Key clinical point: Diets with higher proinflammatory effects as indicated by higher Dietary Inflammatory Index (DII) values are significantly associated with an increased frequency and severity of migraine headaches.

Major finding: After adjusting for potential confounders, an increase in the DII score from −4.04 to −1.83 increased the headache frequency by 3.48 (β 3.48; P = .001) and was associated with a higher risk for severe headaches (odds ratio 2.25; P = .015).

Study details: Findings are from a population-based cross-sectional study including 262 patients with migraine having a body mass index of 18.5-30.0 kg/m² and daily energy consumption of 800-4,200 kcal/day.

Disclosures: The study was funded by Isfahan University of Medical Sciences, Iran. The authors declared no conflict of interests.

Source: Ghoreishy SM et al. Associations between potential inflammatory properties of the diet and frequency, duration, and severity of migraine headaches: a cross-sectional study. Sci Rep. 2022;12:2878 (Feb 21). Doi: 10.1038/s41598-022-06819-y

Key clinical point: Diets with higher proinflammatory effects as indicated by higher Dietary Inflammatory Index (DII) values are significantly associated with an increased frequency and severity of migraine headaches.

Major finding: After adjusting for potential confounders, an increase in the DII score from −4.04 to −1.83 increased the headache frequency by 3.48 (β 3.48; P = .001) and was associated with a higher risk for severe headaches (odds ratio 2.25; P = .015).

Study details: Findings are from a population-based cross-sectional study including 262 patients with migraine having a body mass index of 18.5-30.0 kg/m² and daily energy consumption of 800-4,200 kcal/day.

Disclosures: The study was funded by Isfahan University of Medical Sciences, Iran. The authors declared no conflict of interests.

Source: Ghoreishy SM et al. Associations between potential inflammatory properties of the diet and frequency, duration, and severity of migraine headaches: a cross-sectional study. Sci Rep. 2022;12:2878 (Feb 21). Doi: 10.1038/s41598-022-06819-y

Key clinical point: Diets with higher proinflammatory effects as indicated by higher Dietary Inflammatory Index (DII) values are significantly associated with an increased frequency and severity of migraine headaches.

Major finding: After adjusting for potential confounders, an increase in the DII score from −4.04 to −1.83 increased the headache frequency by 3.48 (β 3.48; P = .001) and was associated with a higher risk for severe headaches (odds ratio 2.25; P = .015).

Study details: Findings are from a population-based cross-sectional study including 262 patients with migraine having a body mass index of 18.5-30.0 kg/m² and daily energy consumption of 800-4,200 kcal/day.

Disclosures: The study was funded by Isfahan University of Medical Sciences, Iran. The authors declared no conflict of interests.

Source: Ghoreishy SM et al. Associations between potential inflammatory properties of the diet and frequency, duration, and severity of migraine headaches: a cross-sectional study. Sci Rep. 2022;12:2878 (Feb 21). Doi: 10.1038/s41598-022-06819-y

Key clinical point: Moderate-to-severe headache days in chronic migraine with medication overuse (CMMO) could be lowered with preventive medication irrespective of whether the overused symptomatic medication is continued or switched to a limited-use alternative.

Major finding: The number of monthly moderate-to-severe headache days achieved with the no switching strategy was not significantly different from that with the switching strategy both during weeks 1-2 (6.4 vs. 6.6 days; P = .57) and 9-12 (9.1 vs. 9.3 days; P = .75) after randomization.

Study details: The data come from MOTS trial including 720 patients aged ≥21 years with CMMO who were randomly assigned to receive migraine prophylactic medication and concurrently either switch from the overused medication to an alternative (≤2 days/week) or continue the overused medication with no maximum limit.

Disclosures: The study was sponsored by a Patient-Centered Outcomes Research Institute Award. Some authors reported receiving personal compensation, research grants, stock options, or royalties from various pharmaceutical companies.

Source: Schwedt T et al. Patient-centered treatment of chronic migraine with medication overuse: A prospective, randomized, pragmatic clinical trial. Neurology. 2022 (Feb 15). Doi: 10.1212/WNL.0000000000200117

Key clinical point: Moderate-to-severe headache days in chronic migraine with medication overuse (CMMO) could be lowered with preventive medication irrespective of whether the overused symptomatic medication is continued or switched to a limited-use alternative.

Major finding: The number of monthly moderate-to-severe headache days achieved with the no switching strategy was not significantly different from that with the switching strategy both during weeks 1-2 (6.4 vs. 6.6 days; P = .57) and 9-12 (9.1 vs. 9.3 days; P = .75) after randomization.

Study details: The data come from MOTS trial including 720 patients aged ≥21 years with CMMO who were randomly assigned to receive migraine prophylactic medication and concurrently either switch from the overused medication to an alternative (≤2 days/week) or continue the overused medication with no maximum limit.

Disclosures: The study was sponsored by a Patient-Centered Outcomes Research Institute Award. Some authors reported receiving personal compensation, research grants, stock options, or royalties from various pharmaceutical companies.

Source: Schwedt T et al. Patient-centered treatment of chronic migraine with medication overuse: A prospective, randomized, pragmatic clinical trial. Neurology. 2022 (Feb 15). Doi: 10.1212/WNL.0000000000200117

Key clinical point: Moderate-to-severe headache days in chronic migraine with medication overuse (CMMO) could be lowered with preventive medication irrespective of whether the overused symptomatic medication is continued or switched to a limited-use alternative.

Major finding: The number of monthly moderate-to-severe headache days achieved with the no switching strategy was not significantly different from that with the switching strategy both during weeks 1-2 (6.4 vs. 6.6 days; P = .57) and 9-12 (9.1 vs. 9.3 days; P = .75) after randomization.

Study details: The data come from MOTS trial including 720 patients aged ≥21 years with CMMO who were randomly assigned to receive migraine prophylactic medication and concurrently either switch from the overused medication to an alternative (≤2 days/week) or continue the overused medication with no maximum limit.

Disclosures: The study was sponsored by a Patient-Centered Outcomes Research Institute Award. Some authors reported receiving personal compensation, research grants, stock options, or royalties from various pharmaceutical companies.

Source: Schwedt T et al. Patient-centered treatment of chronic migraine with medication overuse: A prospective, randomized, pragmatic clinical trial. Neurology. 2022 (Feb 15). Doi: 10.1212/WNL.0000000000200117

Key clinical point: A higher proportion of patients with chronic migraine treated with eptinezumab vs. placebo showed an early treatment response, with most early responders maintaining the response for at least half of the entire 24-week treatment period.

Major finding: At 1 month, a ≥75% reduction in monthly migraine days was achieved by 30.9%, 36.9%, and 15.6% of patients receiving 100 mg eptinezumab, 300 mg eptinezumab, and placebo, respectively. Among patients who achieved a ≥75% migraine response at 1 month, more than one-third and two-thirds maintained the same for the next 5 months and ≥3 months, respectively.

Study details: This was a post hoc analysis of the PROMISE 2 trial, including 1,072 patients with chronic migraine who were randomly assigned to receive 100 mg eptinezumab, 300 mg eptinezumab, or placebo.

Disclosures: The study was funded by H. Lundbeck A/S, Copenhagen. R Cady and T Brevig declared being employees of Lundbeck or a subsidiary company or having equity in Lundbeck, and others declared serving on advisory panels for or receiving grant support, consulting support, or personal compensation from various sources, including Lundbeck.

Source: Buse DC et al. Early response to eptinezumab indicates high likelihood of continued response in patients with chronic migraine. J Headache Pain. 2022;23:29 (Feb 21). Doi: 10.1186/s10194-022-01387-y

Key clinical point: A higher proportion of patients with chronic migraine treated with eptinezumab vs. placebo showed an early treatment response, with most early responders maintaining the response for at least half of the entire 24-week treatment period.

Major finding: At 1 month, a ≥75% reduction in monthly migraine days was achieved by 30.9%, 36.9%, and 15.6% of patients receiving 100 mg eptinezumab, 300 mg eptinezumab, and placebo, respectively. Among patients who achieved a ≥75% migraine response at 1 month, more than one-third and two-thirds maintained the same for the next 5 months and ≥3 months, respectively.

Study details: This was a post hoc analysis of the PROMISE 2 trial, including 1,072 patients with chronic migraine who were randomly assigned to receive 100 mg eptinezumab, 300 mg eptinezumab, or placebo.

Disclosures: The study was funded by H. Lundbeck A/S, Copenhagen. R Cady and T Brevig declared being employees of Lundbeck or a subsidiary company or having equity in Lundbeck, and others declared serving on advisory panels for or receiving grant support, consulting support, or personal compensation from various sources, including Lundbeck.

Source: Buse DC et al. Early response to eptinezumab indicates high likelihood of continued response in patients with chronic migraine. J Headache Pain. 2022;23:29 (Feb 21). Doi: 10.1186/s10194-022-01387-y

Key clinical point: A higher proportion of patients with chronic migraine treated with eptinezumab vs. placebo showed an early treatment response, with most early responders maintaining the response for at least half of the entire 24-week treatment period.

Major finding: At 1 month, a ≥75% reduction in monthly migraine days was achieved by 30.9%, 36.9%, and 15.6% of patients receiving 100 mg eptinezumab, 300 mg eptinezumab, and placebo, respectively. Among patients who achieved a ≥75% migraine response at 1 month, more than one-third and two-thirds maintained the same for the next 5 months and ≥3 months, respectively.

Study details: This was a post hoc analysis of the PROMISE 2 trial, including 1,072 patients with chronic migraine who were randomly assigned to receive 100 mg eptinezumab, 300 mg eptinezumab, or placebo.

Disclosures: The study was funded by H. Lundbeck A/S, Copenhagen. R Cady and T Brevig declared being employees of Lundbeck or a subsidiary company or having equity in Lundbeck, and others declared serving on advisory panels for or receiving grant support, consulting support, or personal compensation from various sources, including Lundbeck.

Source: Buse DC et al. Early response to eptinezumab indicates high likelihood of continued response in patients with chronic migraine. J Headache Pain. 2022;23:29 (Feb 21). Doi: 10.1186/s10194-022-01387-y

Key clinical point: With its efficacy and safety in patients aged ≥50 years with migraine being similar to those in the overall study population in the PROMISE-1 and PROMISE-2 trials, eptinezumab could be an effective treatment option in this subpopulation.

Major finding: Compared with those in the total study population, similar changes in mean monthly migraine days were observed in patients with episodic (least squares mean [LSM] changes in days: 100 mg eptinezumab: −3.6; 300 mg eptinezumab: −4.4; placebo: −2.8) and chronic (LSM changes in days: 100 mg eptinezumab: −7.6; 300 mg `eptinezumab: −8.4; placebo: −6.0) migraine. The incidence of treatment-emergent adverse events was similar among treatment groups.

Study details: Of 1,960 patients with episodic or chronic migraine from the PROMISE-1 and PROMISE-2 trials, this post hoc analysis evaluated 385 patients aged ≥50 years who received eptinezumab or placebo.

Disclosures: H. Lundbeck A/S, Copenhagen, sponsored the study. V Martin and C Tassorelli declared being consultants, speakers, clinical trial investigators, or advisory board members for various companies, including Lundbeck; the rest are current/former employees of Lundbeck or a subsidiary/contracted company.

Source: Martin V et al. Eptinezumab for migraine prevention in patients 50 years or older. Acta Neurol Scand. 2022 (Feb 26). Doi: 10.1111/ane.13603

Key clinical point: With its efficacy and safety in patients aged ≥50 years with migraine being similar to those in the overall study population in the PROMISE-1 and PROMISE-2 trials, eptinezumab could be an effective treatment option in this subpopulation.

Major finding: Compared with those in the total study population, similar changes in mean monthly migraine days were observed in patients with episodic (least squares mean [LSM] changes in days: 100 mg eptinezumab: −3.6; 300 mg eptinezumab: −4.4; placebo: −2.8) and chronic (LSM changes in days: 100 mg eptinezumab: −7.6; 300 mg `eptinezumab: −8.4; placebo: −6.0) migraine. The incidence of treatment-emergent adverse events was similar among treatment groups.

Study details: Of 1,960 patients with episodic or chronic migraine from the PROMISE-1 and PROMISE-2 trials, this post hoc analysis evaluated 385 patients aged ≥50 years who received eptinezumab or placebo.

Disclosures: H. Lundbeck A/S, Copenhagen, sponsored the study. V Martin and C Tassorelli declared being consultants, speakers, clinical trial investigators, or advisory board members for various companies, including Lundbeck; the rest are current/former employees of Lundbeck or a subsidiary/contracted company.

Source: Martin V et al. Eptinezumab for migraine prevention in patients 50 years or older. Acta Neurol Scand. 2022 (Feb 26). Doi: 10.1111/ane.13603

Key clinical point: With its efficacy and safety in patients aged ≥50 years with migraine being similar to those in the overall study population in the PROMISE-1 and PROMISE-2 trials, eptinezumab could be an effective treatment option in this subpopulation.

Major finding: Compared with those in the total study population, similar changes in mean monthly migraine days were observed in patients with episodic (least squares mean [LSM] changes in days: 100 mg eptinezumab: −3.6; 300 mg eptinezumab: −4.4; placebo: −2.8) and chronic (LSM changes in days: 100 mg eptinezumab: −7.6; 300 mg `eptinezumab: −8.4; placebo: −6.0) migraine. The incidence of treatment-emergent adverse events was similar among treatment groups.

Study details: Of 1,960 patients with episodic or chronic migraine from the PROMISE-1 and PROMISE-2 trials, this post hoc analysis evaluated 385 patients aged ≥50 years who received eptinezumab or placebo.

Disclosures: H. Lundbeck A/S, Copenhagen, sponsored the study. V Martin and C Tassorelli declared being consultants, speakers, clinical trial investigators, or advisory board members for various companies, including Lundbeck; the rest are current/former employees of Lundbeck or a subsidiary/contracted company.

Source: Martin V et al. Eptinezumab for migraine prevention in patients 50 years or older. Acta Neurol Scand. 2022 (Feb 26). Doi: 10.1111/ane.13603

Key clinical point: A single intravenous (IV) dose of sodium valproate exerts a better analgesic effect than that of ibuprofen in the treatment of acute migraine attacks.

Major finding: Mean differences in the delta Numerical Rating Scale scores between the sodium valproate and ibuprofen groups were 1.69, 3.61, 4.11, and 3.92 (all P < .001) after 30, 60, 90, and 120 minutes from the time of presentation, respectively, with more patients achieving pain relief with IV sodium valproate (P < .001).

Study details: Findings are from a prospective, double-blinded study including 99 adult patients with migraine without aura who presented to the emergency department with acute headache and were randomly assigned to receive sodium valproate (n = 49) or ibuprofen (n = 50) by IV infusion over 5 minutes.

Disclosures: The authors reported receiving no financial support for the study and declared no conflict of interests.

Source: Dogruyol S et al. Intravenous ibuprofen versus sodium valproate in acute migraine attacks in the emergency department: A randomized clinical trial. Am J Emerg Med. 2022 (Mar 4). Doi:  10.1016/j.ajem.2022.02.046

Key clinical point: A single intravenous (IV) dose of sodium valproate exerts a better analgesic effect than that of ibuprofen in the treatment of acute migraine attacks.

Major finding: Mean differences in the delta Numerical Rating Scale scores between the sodium valproate and ibuprofen groups were 1.69, 3.61, 4.11, and 3.92 (all P < .001) after 30, 60, 90, and 120 minutes from the time of presentation, respectively, with more patients achieving pain relief with IV sodium valproate (P < .001).

Study details: Findings are from a prospective, double-blinded study including 99 adult patients with migraine without aura who presented to the emergency department with acute headache and were randomly assigned to receive sodium valproate (n = 49) or ibuprofen (n = 50) by IV infusion over 5 minutes.

Disclosures: The authors reported receiving no financial support for the study and declared no conflict of interests.

Source: Dogruyol S et al. Intravenous ibuprofen versus sodium valproate in acute migraine attacks in the emergency department: A randomized clinical trial. Am J Emerg Med. 2022 (Mar 4). Doi:  10.1016/j.ajem.2022.02.046

Key clinical point: A single intravenous (IV) dose of sodium valproate exerts a better analgesic effect than that of ibuprofen in the treatment of acute migraine attacks.

Major finding: Mean differences in the delta Numerical Rating Scale scores between the sodium valproate and ibuprofen groups were 1.69, 3.61, 4.11, and 3.92 (all P < .001) after 30, 60, 90, and 120 minutes from the time of presentation, respectively, with more patients achieving pain relief with IV sodium valproate (P < .001).

Study details: Findings are from a prospective, double-blinded study including 99 adult patients with migraine without aura who presented to the emergency department with acute headache and were randomly assigned to receive sodium valproate (n = 49) or ibuprofen (n = 50) by IV infusion over 5 minutes.

Disclosures: The authors reported receiving no financial support for the study and declared no conflict of interests.

Source: Dogruyol S et al. Intravenous ibuprofen versus sodium valproate in acute migraine attacks in the emergency department: A randomized clinical trial. Am J Emerg Med. 2022 (Mar 4). Doi:  10.1016/j.ajem.2022.02.046

Key clinical point: Anodal transcranial direct current stimulation (a-tDCS) of the left motor cortex shows significant prophylactic effects in patients with resistant chronic migraine (CM), including early and long-lasting beneficial effects after the stimulation period.

Major finding: The frequency of monthly migraine attacks reduced significantly in the a-tDCS vs. sham a-tDCS group from the end of the first month (−21.0% vs. −1.5%; P = .019) to the end of 3-month follow-up (−31.9% vs. −5.6%; P = .011), with the rate of responders being significantly higher in the a-tDCS vs. sham a-tDCS group at 3 months posttreatment (50% vs. 14%; P = .043).

Study details: Findings are from a patient-assessor–blinded trial including 36 patients with resistant CM who were randomly assigned to receive a-tDCS (n = 18) or sham a-tDCS (n = 18) over 2 months before a 3-month posttreatment follow-up.

Disclosures: The study received no specific funding. The authors declared no conflict of interests.

Source: Hodaj H et al. Long-term prophylactic efficacy of transcranial direct current stimulation in chronic migraine. A randomised, patient-assessor blinded, sham-controlled trial. Brain Stimul. 2022;15(2):441-453 (Feb 24). Doi: 10.1016/j.brs.2022.02.012

Key clinical point: Anodal transcranial direct current stimulation (a-tDCS) of the left motor cortex shows significant prophylactic effects in patients with resistant chronic migraine (CM), including early and long-lasting beneficial effects after the stimulation period.

Major finding: The frequency of monthly migraine attacks reduced significantly in the a-tDCS vs. sham a-tDCS group from the end of the first month (−21.0% vs. −1.5%; P = .019) to the end of 3-month follow-up (−31.9% vs. −5.6%; P = .011), with the rate of responders being significantly higher in the a-tDCS vs. sham a-tDCS group at 3 months posttreatment (50% vs. 14%; P = .043).

Study details: Findings are from a patient-assessor–blinded trial including 36 patients with resistant CM who were randomly assigned to receive a-tDCS (n = 18) or sham a-tDCS (n = 18) over 2 months before a 3-month posttreatment follow-up.

Disclosures: The study received no specific funding. The authors declared no conflict of interests.

Source: Hodaj H et al. Long-term prophylactic efficacy of transcranial direct current stimulation in chronic migraine. A randomised, patient-assessor blinded, sham-controlled trial. Brain Stimul. 2022;15(2):441-453 (Feb 24). Doi: 10.1016/j.brs.2022.02.012

Key clinical point: Anodal transcranial direct current stimulation (a-tDCS) of the left motor cortex shows significant prophylactic effects in patients with resistant chronic migraine (CM), including early and long-lasting beneficial effects after the stimulation period.

Major finding: The frequency of monthly migraine attacks reduced significantly in the a-tDCS vs. sham a-tDCS group from the end of the first month (−21.0% vs. −1.5%; P = .019) to the end of 3-month follow-up (−31.9% vs. −5.6%; P = .011), with the rate of responders being significantly higher in the a-tDCS vs. sham a-tDCS group at 3 months posttreatment (50% vs. 14%; P = .043).

Study details: Findings are from a patient-assessor–blinded trial including 36 patients with resistant CM who were randomly assigned to receive a-tDCS (n = 18) or sham a-tDCS (n = 18) over 2 months before a 3-month posttreatment follow-up.

Disclosures: The study received no specific funding. The authors declared no conflict of interests.

Source: Hodaj H et al. Long-term prophylactic efficacy of transcranial direct current stimulation in chronic migraine. A randomised, patient-assessor blinded, sham-controlled trial. Brain Stimul. 2022;15(2):441-453 (Feb 24). Doi: 10.1016/j.brs.2022.02.012

Key clinical point: Anti‐calcitonin gene‐related peptide (anti-CGRP) monoclonal antibodies were effective and safe over a 12-month treatment period in patients with treatment-resistant chronic migraine (CM) and medication overuse.

Major finding: Among patients followed up for 12 months, a ≥50% reduction in monthly migraine days and Migraine Disability Assessment score was achieved by 36.4%-66.6% and 84.4%-100% of patients, respectively. No severe treatment-related adverse events were observed.

Study details: Findings are from a prospective, monocentric, cohort study including 203 patients with CM (most also reporting medication overuse) who were resistant to ≥3 preventive treatments and commenced preventive therapy with erenumab, galcanezumab, or fremanezumab.

Disclosures: The study did not receive any financial support. P Geppetti and FD Cesaris reported receiving personal fees and research grants from various sources along with serving as an advisory board member or founding scientist for some sources.

Source: Iannone LF et al. Long-term effectiveness of three anti-CGRP monoclonal antibodies in resistant chronic migraine patients based on the MIDAS score. CNS Drugs. 2022;36:191-202 (Feb 11). Doi: 10.1007/s40263-021-00893-y

Key clinical point: Anti‐calcitonin gene‐related peptide (anti-CGRP) monoclonal antibodies were effective and safe over a 12-month treatment period in patients with treatment-resistant chronic migraine (CM) and medication overuse.

Major finding: Among patients followed up for 12 months, a ≥50% reduction in monthly migraine days and Migraine Disability Assessment score was achieved by 36.4%-66.6% and 84.4%-100% of patients, respectively. No severe treatment-related adverse events were observed.

Study details: Findings are from a prospective, monocentric, cohort study including 203 patients with CM (most also reporting medication overuse) who were resistant to ≥3 preventive treatments and commenced preventive therapy with erenumab, galcanezumab, or fremanezumab.

Disclosures: The study did not receive any financial support. P Geppetti and FD Cesaris reported receiving personal fees and research grants from various sources along with serving as an advisory board member or founding scientist for some sources.

Source: Iannone LF et al. Long-term effectiveness of three anti-CGRP monoclonal antibodies in resistant chronic migraine patients based on the MIDAS score. CNS Drugs. 2022;36:191-202 (Feb 11). Doi: 10.1007/s40263-021-00893-y

Key clinical point: Anti‐calcitonin gene‐related peptide (anti-CGRP) monoclonal antibodies were effective and safe over a 12-month treatment period in patients with treatment-resistant chronic migraine (CM) and medication overuse.

Major finding: Among patients followed up for 12 months, a ≥50% reduction in monthly migraine days and Migraine Disability Assessment score was achieved by 36.4%-66.6% and 84.4%-100% of patients, respectively. No severe treatment-related adverse events were observed.

Study details: Findings are from a prospective, monocentric, cohort study including 203 patients with CM (most also reporting medication overuse) who were resistant to ≥3 preventive treatments and commenced preventive therapy with erenumab, galcanezumab, or fremanezumab.

Disclosures: The study did not receive any financial support. P Geppetti and FD Cesaris reported receiving personal fees and research grants from various sources along with serving as an advisory board member or founding scientist for some sources.

Source: Iannone LF et al. Long-term effectiveness of three anti-CGRP monoclonal antibodies in resistant chronic migraine patients based on the MIDAS score. CNS Drugs. 2022;36:191-202 (Feb 11). Doi: 10.1007/s40263-021-00893-y

Circulating tumor DNA (ctDNA) is unreliable for detecting colorectal cancer recurrences after resection, conclude the authors of a review of 48 patients at the City of Hope Comprehensive Cancer Center, outside of Los Angeles.

Two ctDNA tests that are used for this purpose are already marketed in the United States: Signatera (Natera) and Reveal (Guardant Health).

This use of ctDNA has been catching on with oncologists in the United States, noted the authors. Such use is based on the premise that the test catches recurrences earlier than imaging and carcinoembryonic antigen (CEA) monitoring, which is the standard approach recommended by the National Comprehensive Cancer Network and the European Society of Medical Oncology.

The review was published online on March 8, 2022, in JAMA Network Open.

The review included 48 patients with stage II-IV colorectal cancer whose disease was in remission after curative-intent surgery. They were followed with CT imaging and CEA, as per NCCN guidelines, and with the Signatera ctDNA test from Natera.

The authors, led by Marwan Fakih, MD, a gastrointestinal oncologist at City of Hope, concluded that ctDNA “provides no definitive advantage compared with standard imaging and CEA measurement in the surveillance of patients with resected colorectal cancer.”

In fact, they suggested that clinicians “have taken a giant leap of faith by endorsing ctDNA assays as predictive and prognostic.” They noted that ongoing phase 3 trials are investigating the deescalation or even elimination of adjuvant chemotherapy, based on negative ctDNA results, as, for example, in a study reported recently at the 2022 Gastrointestinal Cancers Symposium.

“For now, ctDNA can be considered, if ... at all, as a complement to the standard approach recommended by the NCCN, but one must be cognizant of its limitations,” Dr. Fakih commented in a press release.

Asked for comment, Natera countered that its test is backed by “over a dozen peer-reviewed studies, with over 3,000 patients studied across multiple cancer types.” About the review, the company said that “small clinical experience studies are subject to limitations and variability.” It also emphasized that the company “has always supported the use of Signatera in combination with imaging,” not as a replacement.
 

Study details

Among the 49 patients included in the review, 15 experienced recurrence, but only eight of these patients had concurrent positive results on ctDNA.

Five of eight patients with lung recurrences were identified by CT imaging before the ctDNA test was positive or had persistently negative ctDNA results.

“A negative ctDNA finding is common in the setting of low-volume metastatic disease, especially in metastatic disease of the lung,” the investigators said.

Imaging plus CEA identified recurrences before ctDNA in seven cases, and it did so concurrently with ctDNA in four cases, yielding a sensitivity of 73.3% for recurrence versus 53.3% for ctDNA, but the finding wasn’t statistically significant, owing to the small number of patients.

The ctDNA test did identify five patients before imaging, but the investigators said it was “unlikely” that the finding changed treatment.

One patient had multiple lung metastases, and two patients had diffuse retroperitoneal disease, so none of the three were candidates for curative-intent surgery.

The other two patients did undergo surgery, but the investigators said they “would have arguably experienced a similar intervention if followed up by standard surveillance.”

The two retroperitoneal cases were positive on ctDNA for well over a year before recurrences showed up on imaging, which raises another point, commented the author of an accompanying commentary.

Discovering minimal residual disease (MRD) by “ctDNA before the site of recurrence can be localized” for surgery “does not open the window of opportunity. Instead ... patients receive bad news that is not actionable” and “might be harmed” by “learning of inevitable cancer recurrence with nothing to do but wait,” Alan Venook, MD, a gastrointestinal oncologist at the University of California, San Francisco, wrote in the commentary.

“If ctDNA can indeed detect MRD sooner than imaging, then interventional trials with molecular response as an end point are warranted to determine whether ctDNA detection is an actionable finding,” he said.

Dr. Fakih and associates noted that much of “the enthusiasm around these assays, particularly Signatera, was generated by a large observational surveillance trial” in Denmark that found that ctDNA identified disease recurrence an average of 8.7 months before CT imaging.

However, imaging was performed at 1 and 3 years, which they say is “considered substandard” in the United States and many European countries.

There was no funding for the review. Dr. Fakih has numerous ties with industry, including being a speaker for Guardant360; parent company Guardant Health markets a rival ctDNA test, Guardant Reveal. Dr. Fakih is also a speaker for Amgen and is an adviser for and/or receives institutional grants from Amgen, GlaxoSmithKline, Bristol-Myers Squibb, and others. Dr. Venook has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Circulating tumor DNA (ctDNA) is unreliable for detecting colorectal cancer recurrences after resection, conclude the authors of a review of 48 patients at the City of Hope Comprehensive Cancer Center, outside of Los Angeles.

Two ctDNA tests that are used for this purpose are already marketed in the United States: Signatera (Natera) and Reveal (Guardant Health).

This use of ctDNA has been catching on with oncologists in the United States, noted the authors. Such use is based on the premise that the test catches recurrences earlier than imaging and carcinoembryonic antigen (CEA) monitoring, which is the standard approach recommended by the National Comprehensive Cancer Network and the European Society of Medical Oncology.

The review was published online on March 8, 2022, in JAMA Network Open.

The review included 48 patients with stage II-IV colorectal cancer whose disease was in remission after curative-intent surgery. They were followed with CT imaging and CEA, as per NCCN guidelines, and with the Signatera ctDNA test from Natera.

The authors, led by Marwan Fakih, MD, a gastrointestinal oncologist at City of Hope, concluded that ctDNA “provides no definitive advantage compared with standard imaging and CEA measurement in the surveillance of patients with resected colorectal cancer.”

In fact, they suggested that clinicians “have taken a giant leap of faith by endorsing ctDNA assays as predictive and prognostic.” They noted that ongoing phase 3 trials are investigating the deescalation or even elimination of adjuvant chemotherapy, based on negative ctDNA results, as, for example, in a study reported recently at the 2022 Gastrointestinal Cancers Symposium.

“For now, ctDNA can be considered, if ... at all, as a complement to the standard approach recommended by the NCCN, but one must be cognizant of its limitations,” Dr. Fakih commented in a press release.

Asked for comment, Natera countered that its test is backed by “over a dozen peer-reviewed studies, with over 3,000 patients studied across multiple cancer types.” About the review, the company said that “small clinical experience studies are subject to limitations and variability.” It also emphasized that the company “has always supported the use of Signatera in combination with imaging,” not as a replacement.
 

Study details

Among the 49 patients included in the review, 15 experienced recurrence, but only eight of these patients had concurrent positive results on ctDNA.

Five of eight patients with lung recurrences were identified by CT imaging before the ctDNA test was positive or had persistently negative ctDNA results.

“A negative ctDNA finding is common in the setting of low-volume metastatic disease, especially in metastatic disease of the lung,” the investigators said.

Imaging plus CEA identified recurrences before ctDNA in seven cases, and it did so concurrently with ctDNA in four cases, yielding a sensitivity of 73.3% for recurrence versus 53.3% for ctDNA, but the finding wasn’t statistically significant, owing to the small number of patients.

The ctDNA test did identify five patients before imaging, but the investigators said it was “unlikely” that the finding changed treatment.

One patient had multiple lung metastases, and two patients had diffuse retroperitoneal disease, so none of the three were candidates for curative-intent surgery.

The other two patients did undergo surgery, but the investigators said they “would have arguably experienced a similar intervention if followed up by standard surveillance.”

The two retroperitoneal cases were positive on ctDNA for well over a year before recurrences showed up on imaging, which raises another point, commented the author of an accompanying commentary.

Discovering minimal residual disease (MRD) by “ctDNA before the site of recurrence can be localized” for surgery “does not open the window of opportunity. Instead ... patients receive bad news that is not actionable” and “might be harmed” by “learning of inevitable cancer recurrence with nothing to do but wait,” Alan Venook, MD, a gastrointestinal oncologist at the University of California, San Francisco, wrote in the commentary.

“If ctDNA can indeed detect MRD sooner than imaging, then interventional trials with molecular response as an end point are warranted to determine whether ctDNA detection is an actionable finding,” he said.

Dr. Fakih and associates noted that much of “the enthusiasm around these assays, particularly Signatera, was generated by a large observational surveillance trial” in Denmark that found that ctDNA identified disease recurrence an average of 8.7 months before CT imaging.

However, imaging was performed at 1 and 3 years, which they say is “considered substandard” in the United States and many European countries.

There was no funding for the review. Dr. Fakih has numerous ties with industry, including being a speaker for Guardant360; parent company Guardant Health markets a rival ctDNA test, Guardant Reveal. Dr. Fakih is also a speaker for Amgen and is an adviser for and/or receives institutional grants from Amgen, GlaxoSmithKline, Bristol-Myers Squibb, and others. Dr. Venook has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Circulating tumor DNA (ctDNA) is unreliable for detecting colorectal cancer recurrences after resection, conclude the authors of a review of 48 patients at the City of Hope Comprehensive Cancer Center, outside of Los Angeles.

Two ctDNA tests that are used for this purpose are already marketed in the United States: Signatera (Natera) and Reveal (Guardant Health).

This use of ctDNA has been catching on with oncologists in the United States, noted the authors. Such use is based on the premise that the test catches recurrences earlier than imaging and carcinoembryonic antigen (CEA) monitoring, which is the standard approach recommended by the National Comprehensive Cancer Network and the European Society of Medical Oncology.

The review was published online on March 8, 2022, in JAMA Network Open.

The review included 48 patients with stage II-IV colorectal cancer whose disease was in remission after curative-intent surgery. They were followed with CT imaging and CEA, as per NCCN guidelines, and with the Signatera ctDNA test from Natera.

The authors, led by Marwan Fakih, MD, a gastrointestinal oncologist at City of Hope, concluded that ctDNA “provides no definitive advantage compared with standard imaging and CEA measurement in the surveillance of patients with resected colorectal cancer.”

In fact, they suggested that clinicians “have taken a giant leap of faith by endorsing ctDNA assays as predictive and prognostic.” They noted that ongoing phase 3 trials are investigating the deescalation or even elimination of adjuvant chemotherapy, based on negative ctDNA results, as, for example, in a study reported recently at the 2022 Gastrointestinal Cancers Symposium.

“For now, ctDNA can be considered, if ... at all, as a complement to the standard approach recommended by the NCCN, but one must be cognizant of its limitations,” Dr. Fakih commented in a press release.

Asked for comment, Natera countered that its test is backed by “over a dozen peer-reviewed studies, with over 3,000 patients studied across multiple cancer types.” About the review, the company said that “small clinical experience studies are subject to limitations and variability.” It also emphasized that the company “has always supported the use of Signatera in combination with imaging,” not as a replacement.
 

Study details

Among the 49 patients included in the review, 15 experienced recurrence, but only eight of these patients had concurrent positive results on ctDNA.

Five of eight patients with lung recurrences were identified by CT imaging before the ctDNA test was positive or had persistently negative ctDNA results.

“A negative ctDNA finding is common in the setting of low-volume metastatic disease, especially in metastatic disease of the lung,” the investigators said.

Imaging plus CEA identified recurrences before ctDNA in seven cases, and it did so concurrently with ctDNA in four cases, yielding a sensitivity of 73.3% for recurrence versus 53.3% for ctDNA, but the finding wasn’t statistically significant, owing to the small number of patients.

The ctDNA test did identify five patients before imaging, but the investigators said it was “unlikely” that the finding changed treatment.

One patient had multiple lung metastases, and two patients had diffuse retroperitoneal disease, so none of the three were candidates for curative-intent surgery.

The other two patients did undergo surgery, but the investigators said they “would have arguably experienced a similar intervention if followed up by standard surveillance.”

The two retroperitoneal cases were positive on ctDNA for well over a year before recurrences showed up on imaging, which raises another point, commented the author of an accompanying commentary.

Discovering minimal residual disease (MRD) by “ctDNA before the site of recurrence can be localized” for surgery “does not open the window of opportunity. Instead ... patients receive bad news that is not actionable” and “might be harmed” by “learning of inevitable cancer recurrence with nothing to do but wait,” Alan Venook, MD, a gastrointestinal oncologist at the University of California, San Francisco, wrote in the commentary.

“If ctDNA can indeed detect MRD sooner than imaging, then interventional trials with molecular response as an end point are warranted to determine whether ctDNA detection is an actionable finding,” he said.

Dr. Fakih and associates noted that much of “the enthusiasm around these assays, particularly Signatera, was generated by a large observational surveillance trial” in Denmark that found that ctDNA identified disease recurrence an average of 8.7 months before CT imaging.

However, imaging was performed at 1 and 3 years, which they say is “considered substandard” in the United States and many European countries.

There was no funding for the review. Dr. Fakih has numerous ties with industry, including being a speaker for Guardant360; parent company Guardant Health markets a rival ctDNA test, Guardant Reveal. Dr. Fakih is also a speaker for Amgen and is an adviser for and/or receives institutional grants from Amgen, GlaxoSmithKline, Bristol-Myers Squibb, and others. Dr. Venook has disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

A large registry-based cohort study in Sweden has revealed that 75% of children born before 24 weeks of gestation had neurodevelopmental disorders, including intellectual disabilities and autism, and required habilitative services.

In addition, somatic disorders such as asthma and failure to thrive/short stature were diagnosed in 88% of the cohort. The findings, published in Acta Paediatrica, emphasize the need for further study of this population, especially as survival rates continue to increase.

“The primary aim of this large, retrospective, national study was to report clinical diagnoses registered after children born before 24 weeks were discharged from neonatal care,” explained lead author Eva Morsing, MD, PhD, of Lund (Sweden) University, and colleagues.

Data on diagnoses of neurodevelopmental disorders and selected somatic diagnoses were obtained from national Swedish registries. Study participants’ individual medical files were also examined by the researchers.
 

Results

The study cohort comprised 383 infants born at a median of 23.3 weeks of gestation (range, 21.9-23.9 weeks). The median birthweight of participants was 565 grams (range, 340-874 grams), with a median birthweight standard deviation (SD) of −0.40 (range, −3.63–3.17).

The majority (75%) of infants had a neurodevelopmental disorder, including speech disorders (52%), intellectual disabilities (40%), attention-deficit/hyperactivity disorder (30%), autism spectrum disorder (24%), visual impairment (22%), cerebral palsy (17%), epilepsy (10%), and hearing impairment (5%).

With respect to gender, a greater number of boys than girls born at 23 weeks had intellectual disabilities (45% vs. 27%; P < .01) and visual impairment (25% vs. 14%; P < .01). Moreover, 55% of the participants were referred for habilitative services.

With respect to somatic diagnoses, failure to thrive/short stature was diagnosed in 39% of the cohort, and it occurred more often in those born at 21 and 22 weeks than in those born at 23 weeks (49% vs. 36%; P < .05).

In addition, asthma and childhood bronchopulmonary dysplasia, pulmonary hypertension, and vocal cord paresis were diagnosed in 63%, 12%, and 13% of participants, respectively.

“Several studies have reported higher rates of preterm morbidities, and poor neurodevelopmental outcomes after extremely preterm birth in boys rather than girls,” study author Ann Hellström, MD, PhD, of the University of Gothenburg, Sweden, said in an interview.

“While the reasons for this were not studied in the present paper, reports in the literature suggest that boys have a higher average growth rate than girls and appear to be more sensitive to suboptimal neonatal nutrition than girls,” Dr. Hellström explained.

“We also know that sex steroids differ in relation to intrauterine life depending on the sex after preterm birth,” Dr. Hellström added.

In an accompanying editorial, Neil Marlow, MD, of University College London, wrote, “One headline from this study [that is interesting] is the high prevalence of autistic spectrum disorders recorded.

“This is a particular finding in extremely preterm cohorts from Sweden, who record more diagnoses than in other longitudinal studies,” Dr. Marlow added. “It certainly warrants further investigation and understanding.”

The researchers acknowledged that a key limitation of the study was the broad age range at the most recent follow-up visit, which ranged from 2 to 13 years, explaining that some diagnoses may occur later in childhood.

“Neonatal clinical practice needs to adopt a long-term perspective and clinicians treating children and adults should be aware of the complicated health problems of children born before 24 weeks,” they concluded.

This study was supported by the Swedish Medical Research Council, the Gothenburg Medical Society, and by grant funding from the Swedish government. The authors reported no relevant disclosures.

A large registry-based cohort study in Sweden has revealed that 75% of children born before 24 weeks of gestation had neurodevelopmental disorders, including intellectual disabilities and autism, and required habilitative services.

In addition, somatic disorders such as asthma and failure to thrive/short stature were diagnosed in 88% of the cohort. The findings, published in Acta Paediatrica, emphasize the need for further study of this population, especially as survival rates continue to increase.

“The primary aim of this large, retrospective, national study was to report clinical diagnoses registered after children born before 24 weeks were discharged from neonatal care,” explained lead author Eva Morsing, MD, PhD, of Lund (Sweden) University, and colleagues.

Data on diagnoses of neurodevelopmental disorders and selected somatic diagnoses were obtained from national Swedish registries. Study participants’ individual medical files were also examined by the researchers.
 

Results

The study cohort comprised 383 infants born at a median of 23.3 weeks of gestation (range, 21.9-23.9 weeks). The median birthweight of participants was 565 grams (range, 340-874 grams), with a median birthweight standard deviation (SD) of −0.40 (range, −3.63–3.17).

The majority (75%) of infants had a neurodevelopmental disorder, including speech disorders (52%), intellectual disabilities (40%), attention-deficit/hyperactivity disorder (30%), autism spectrum disorder (24%), visual impairment (22%), cerebral palsy (17%), epilepsy (10%), and hearing impairment (5%).

With respect to gender, a greater number of boys than girls born at 23 weeks had intellectual disabilities (45% vs. 27%; P < .01) and visual impairment (25% vs. 14%; P < .01). Moreover, 55% of the participants were referred for habilitative services.

With respect to somatic diagnoses, failure to thrive/short stature was diagnosed in 39% of the cohort, and it occurred more often in those born at 21 and 22 weeks than in those born at 23 weeks (49% vs. 36%; P < .05).

In addition, asthma and childhood bronchopulmonary dysplasia, pulmonary hypertension, and vocal cord paresis were diagnosed in 63%, 12%, and 13% of participants, respectively.

“Several studies have reported higher rates of preterm morbidities, and poor neurodevelopmental outcomes after extremely preterm birth in boys rather than girls,” study author Ann Hellström, MD, PhD, of the University of Gothenburg, Sweden, said in an interview.

“While the reasons for this were not studied in the present paper, reports in the literature suggest that boys have a higher average growth rate than girls and appear to be more sensitive to suboptimal neonatal nutrition than girls,” Dr. Hellström explained.

“We also know that sex steroids differ in relation to intrauterine life depending on the sex after preterm birth,” Dr. Hellström added.

In an accompanying editorial, Neil Marlow, MD, of University College London, wrote, “One headline from this study [that is interesting] is the high prevalence of autistic spectrum disorders recorded.

“This is a particular finding in extremely preterm cohorts from Sweden, who record more diagnoses than in other longitudinal studies,” Dr. Marlow added. “It certainly warrants further investigation and understanding.”

The researchers acknowledged that a key limitation of the study was the broad age range at the most recent follow-up visit, which ranged from 2 to 13 years, explaining that some diagnoses may occur later in childhood.

“Neonatal clinical practice needs to adopt a long-term perspective and clinicians treating children and adults should be aware of the complicated health problems of children born before 24 weeks,” they concluded.

This study was supported by the Swedish Medical Research Council, the Gothenburg Medical Society, and by grant funding from the Swedish government. The authors reported no relevant disclosures.

A large registry-based cohort study in Sweden has revealed that 75% of children born before 24 weeks of gestation had neurodevelopmental disorders, including intellectual disabilities and autism, and required habilitative services.

In addition, somatic disorders such as asthma and failure to thrive/short stature were diagnosed in 88% of the cohort. The findings, published in Acta Paediatrica, emphasize the need for further study of this population, especially as survival rates continue to increase.

“The primary aim of this large, retrospective, national study was to report clinical diagnoses registered after children born before 24 weeks were discharged from neonatal care,” explained lead author Eva Morsing, MD, PhD, of Lund (Sweden) University, and colleagues.

Data on diagnoses of neurodevelopmental disorders and selected somatic diagnoses were obtained from national Swedish registries. Study participants’ individual medical files were also examined by the researchers.
 

Results

The study cohort comprised 383 infants born at a median of 23.3 weeks of gestation (range, 21.9-23.9 weeks). The median birthweight of participants was 565 grams (range, 340-874 grams), with a median birthweight standard deviation (SD) of −0.40 (range, −3.63–3.17).

The majority (75%) of infants had a neurodevelopmental disorder, including speech disorders (52%), intellectual disabilities (40%), attention-deficit/hyperactivity disorder (30%), autism spectrum disorder (24%), visual impairment (22%), cerebral palsy (17%), epilepsy (10%), and hearing impairment (5%).

With respect to gender, a greater number of boys than girls born at 23 weeks had intellectual disabilities (45% vs. 27%; P < .01) and visual impairment (25% vs. 14%; P < .01). Moreover, 55% of the participants were referred for habilitative services.

With respect to somatic diagnoses, failure to thrive/short stature was diagnosed in 39% of the cohort, and it occurred more often in those born at 21 and 22 weeks than in those born at 23 weeks (49% vs. 36%; P < .05).

In addition, asthma and childhood bronchopulmonary dysplasia, pulmonary hypertension, and vocal cord paresis were diagnosed in 63%, 12%, and 13% of participants, respectively.

“Several studies have reported higher rates of preterm morbidities, and poor neurodevelopmental outcomes after extremely preterm birth in boys rather than girls,” study author Ann Hellström, MD, PhD, of the University of Gothenburg, Sweden, said in an interview.

“While the reasons for this were not studied in the present paper, reports in the literature suggest that boys have a higher average growth rate than girls and appear to be more sensitive to suboptimal neonatal nutrition than girls,” Dr. Hellström explained.

“We also know that sex steroids differ in relation to intrauterine life depending on the sex after preterm birth,” Dr. Hellström added.

In an accompanying editorial, Neil Marlow, MD, of University College London, wrote, “One headline from this study [that is interesting] is the high prevalence of autistic spectrum disorders recorded.

“This is a particular finding in extremely preterm cohorts from Sweden, who record more diagnoses than in other longitudinal studies,” Dr. Marlow added. “It certainly warrants further investigation and understanding.”

The researchers acknowledged that a key limitation of the study was the broad age range at the most recent follow-up visit, which ranged from 2 to 13 years, explaining that some diagnoses may occur later in childhood.

“Neonatal clinical practice needs to adopt a long-term perspective and clinicians treating children and adults should be aware of the complicated health problems of children born before 24 weeks,” they concluded.

This study was supported by the Swedish Medical Research Council, the Gothenburg Medical Society, and by grant funding from the Swedish government. The authors reported no relevant disclosures.

Seroprevalence surveys suggest that, from the beginning of the pandemic to 2022, more than a third of the global population had been infected with SARS-CoV-2. As large numbers of people continue to be infected, the efficacy and duration of natural immunity, in terms of protection against SARS-CoV-2 reinfections and severe disease, are of crucial significance. The virus’s epidemiologic trajectory will be influenced by the trends in vaccine-induced and hybrid immunity.

Omicron’s immune evasion

Cases of SARS-CoV-2 reinfection are increasing around the world. According to data from the U.K. Health Security Agency, 650,000 people in England have been infected twice, and most of them were reinfected in the past 2 months. Before mid-November 2021, reinfections accounted for about 1% of reported cases, but the rate has now increased to around 10%. The reinfection risk was 16 times higher between mid-December 2021 and early January 2022. Experts believe that this spike in reinfections is related to the spread of Omicron, which overtook Delta as the dominant variant. Nonetheless, other aspects should also be considered.

Omicron’s greater propensity to spread is not unrelated to its ability to evade the body’s immune defenses. This aspect was raised in a letter recently published in the New England Journal of Medicine. The authors reported that the effectiveness of previous infection in preventing reinfection against the Alpha, Beta, and Delta variants was around 90%, but it was only 56% against Omicron.
 

Natural immunity

Natural immunity showed roughly similar effectiveness regarding protection against reinfection across different SARS-CoV-2 variants, with the exception of the Omicron variant. The risk of hospitalization and death was also reduced in SARS-CoV-2 reinfections versus primary infections. Observational studies indicate that natural immunity may offer equal or greater protection against SARS-CoV-2 infections, compared with immunization with two doses of an mRNA vaccine, but the data are not fully consistent.

Natural immunity seems to be relatively long-lasting. Data from Denmark and Austria show no evidence that protection against reinfections wanes after 6 months. Some investigations indicate that protection against reinfection is lowest 4-5 months after initial infection and increases thereafter, a finding that might hypothetically be explained by persistent viral shedding; that is, misclassification of prolonged SARS-CoV-2 infections as reinfections. While no comparison was made against information pertaining to unvaccinated, not previously-infected individuals, preliminary data from Israel suggest that protection from reinfection can decrease from 6 to more than 12 months after the first SARS-CoV-2 infection. Taken together, epidemiologic studies indicate that protection against reinfections by natural immunity lasts over 1 year with only moderate, if any, decline over this period. Among older individuals, immunocompromised patients, and those with certain comorbidities or exposure risk (for example, health care workers), rates of reinfection may be higher. It is plausible that reinfection risk may be a function of exposure risk.

There is accumulating evidence that reinfections may be significantly less severe than primary infections with SARS-CoV-2. Reduced clinical severity of SARS-CoV-2 reinfections naturally also makes sense from a biologic point of view, inasmuch as a previously primed immune system should be better prepared for a rechallenge with this virus.
 

Vaccine-induced immunity

The short-term (<4 months) efficacy of mRNA vaccines against SARS-CoV-2 is high and varies from 94.1% (Moderna) to 95% (BioNTech/Pfizer). This has been confirmed by randomized controlled trials and was subsequently confirmed in effectiveness studies in real-world settings. Waning efficacy was observed with respect to protection against SARS-CoV-2 infections (for example, only approximately 20% after about half a year in Qatar), whereas protection against severe disease was either sustained or showed only a moderate decline.

In individuals who received two doses of the BioNTech/Pfizer vaccine at least 5 months earlier, an additional vaccine dose, a so-called booster, significantly lowered mortality and severe illness. These findings suggest that the booster restored and probably exceeded the initial short-term efficacy of the initial vaccination.

Data are still emerging regarding the efficacy of boosters against the Omicron variants. Preliminary data suggest a far lower ability to restore protection from infection and vaccination. However, fatalities and hospitalizations remain low.
 

Natural immunity vs. vaccine-induced immunity

Comparisons of natural immunity with vaccine-induced immunity are complicated by a series of biases and by combinations of biases – for example, the biases of comparisons between infected and uninfected, plus the biases of comparisons between vaccinated and nonvaccinated, with strong potential selection biases and confounding. Of particular note, the proportion of people previously infected and/or vaccinated may influence estimates of effectiveness. Regarding this point, one study compared unvaccinated patients with a prior SARS-CoV-2 infection and vaccinated individuals followed up from a week after the second vaccine dose onward versus a group of unvaccinated, not previously infected individuals. The findings showed that, compared with unvaccinated, not previously infected individuals, the natural immunity group and the vaccinated group had similar protection of 94.8% and 92.8% against infection, of 94.1% and 94.2% against hospitalization, and of 96.4% and 94.4% against severe illness, respectively.

Hybrid immunity

The combination of a previous SARS-CoV-2 infection and a respective vaccination is called hybrid immunity. This combination seems to confer the greatest protection against SARS-CoV-2 infections, but several knowledge gaps remain regarding this issue.

Data from Israel showed that, when the time since the last immunity-conferring event (either primary infection or vaccination) was the same, the rates of SARS-CoV-2 infections were similar in the following groups: individuals who had a previous infection and no vaccination, individuals who had an infection and were then vaccinated with a single dose after at least 3 months, and individuals who were vaccinated (two doses) and then infected. Severe disease was relatively rare overall.

Data on the efficacy of hybrid immunity point in the direction of hybrid immunity being superior, as compared with either vaccine-induced (without a booster) immunity or natural immunity alone. Timing and mode of vaccination of previously infected individuals to achieve optimal hybrid immunity are central questions that remain to be addressed in future studies.

Given that vaccination rates are continuously increasing and that, by the beginning of 2022, perhaps half or more of the global population had already been infected with SARS-CoV-2, with the vast majority of this group not being officially detected, it would appear logical that future infection waves, even with highly transmissible variants of SARS-CoV-2, may be limited with respect to their maximum potential health burden. The advent of Omicron suggests that massive surges can occur even in populations with extremely high rates of previous vaccination and variable rates of prior infections. However, even then, the accompanying burden of hospitalizations and deaths is far less than what was seen in 2020 and 2021. One may argue that the pandemic has already transitioned to the endemic phase and that Omicron is an endemic wave occurring in the setting of already widespread population immunity.

A version of this article first appeared on Medscape.com.

Seroprevalence surveys suggest that, from the beginning of the pandemic to 2022, more than a third of the global population had been infected with SARS-CoV-2. As large numbers of people continue to be infected, the efficacy and duration of natural immunity, in terms of protection against SARS-CoV-2 reinfections and severe disease, are of crucial significance. The virus’s epidemiologic trajectory will be influenced by the trends in vaccine-induced and hybrid immunity.

Omicron’s immune evasion

Cases of SARS-CoV-2 reinfection are increasing around the world. According to data from the U.K. Health Security Agency, 650,000 people in England have been infected twice, and most of them were reinfected in the past 2 months. Before mid-November 2021, reinfections accounted for about 1% of reported cases, but the rate has now increased to around 10%. The reinfection risk was 16 times higher between mid-December 2021 and early January 2022. Experts believe that this spike in reinfections is related to the spread of Omicron, which overtook Delta as the dominant variant. Nonetheless, other aspects should also be considered.

Omicron’s greater propensity to spread is not unrelated to its ability to evade the body’s immune defenses. This aspect was raised in a letter recently published in the New England Journal of Medicine. The authors reported that the effectiveness of previous infection in preventing reinfection against the Alpha, Beta, and Delta variants was around 90%, but it was only 56% against Omicron.
 

Natural immunity

Natural immunity showed roughly similar effectiveness regarding protection against reinfection across different SARS-CoV-2 variants, with the exception of the Omicron variant. The risk of hospitalization and death was also reduced in SARS-CoV-2 reinfections versus primary infections. Observational studies indicate that natural immunity may offer equal or greater protection against SARS-CoV-2 infections, compared with immunization with two doses of an mRNA vaccine, but the data are not fully consistent.

Natural immunity seems to be relatively long-lasting. Data from Denmark and Austria show no evidence that protection against reinfections wanes after 6 months. Some investigations indicate that protection against reinfection is lowest 4-5 months after initial infection and increases thereafter, a finding that might hypothetically be explained by persistent viral shedding; that is, misclassification of prolonged SARS-CoV-2 infections as reinfections. While no comparison was made against information pertaining to unvaccinated, not previously-infected individuals, preliminary data from Israel suggest that protection from reinfection can decrease from 6 to more than 12 months after the first SARS-CoV-2 infection. Taken together, epidemiologic studies indicate that protection against reinfections by natural immunity lasts over 1 year with only moderate, if any, decline over this period. Among older individuals, immunocompromised patients, and those with certain comorbidities or exposure risk (for example, health care workers), rates of reinfection may be higher. It is plausible that reinfection risk may be a function of exposure risk.

There is accumulating evidence that reinfections may be significantly less severe than primary infections with SARS-CoV-2. Reduced clinical severity of SARS-CoV-2 reinfections naturally also makes sense from a biologic point of view, inasmuch as a previously primed immune system should be better prepared for a rechallenge with this virus.
 

Vaccine-induced immunity

The short-term (<4 months) efficacy of mRNA vaccines against SARS-CoV-2 is high and varies from 94.1% (Moderna) to 95% (BioNTech/Pfizer). This has been confirmed by randomized controlled trials and was subsequently confirmed in effectiveness studies in real-world settings. Waning efficacy was observed with respect to protection against SARS-CoV-2 infections (for example, only approximately 20% after about half a year in Qatar), whereas protection against severe disease was either sustained or showed only a moderate decline.

In individuals who received two doses of the BioNTech/Pfizer vaccine at least 5 months earlier, an additional vaccine dose, a so-called booster, significantly lowered mortality and severe illness. These findings suggest that the booster restored and probably exceeded the initial short-term efficacy of the initial vaccination.

Data are still emerging regarding the efficacy of boosters against the Omicron variants. Preliminary data suggest a far lower ability to restore protection from infection and vaccination. However, fatalities and hospitalizations remain low.
 

Natural immunity vs. vaccine-induced immunity

Comparisons of natural immunity with vaccine-induced immunity are complicated by a series of biases and by combinations of biases – for example, the biases of comparisons between infected and uninfected, plus the biases of comparisons between vaccinated and nonvaccinated, with strong potential selection biases and confounding. Of particular note, the proportion of people previously infected and/or vaccinated may influence estimates of effectiveness. Regarding this point, one study compared unvaccinated patients with a prior SARS-CoV-2 infection and vaccinated individuals followed up from a week after the second vaccine dose onward versus a group of unvaccinated, not previously infected individuals. The findings showed that, compared with unvaccinated, not previously infected individuals, the natural immunity group and the vaccinated group had similar protection of 94.8% and 92.8% against infection, of 94.1% and 94.2% against hospitalization, and of 96.4% and 94.4% against severe illness, respectively.

Hybrid immunity

The combination of a previous SARS-CoV-2 infection and a respective vaccination is called hybrid immunity. This combination seems to confer the greatest protection against SARS-CoV-2 infections, but several knowledge gaps remain regarding this issue.

Data from Israel showed that, when the time since the last immunity-conferring event (either primary infection or vaccination) was the same, the rates of SARS-CoV-2 infections were similar in the following groups: individuals who had a previous infection and no vaccination, individuals who had an infection and were then vaccinated with a single dose after at least 3 months, and individuals who were vaccinated (two doses) and then infected. Severe disease was relatively rare overall.

Data on the efficacy of hybrid immunity point in the direction of hybrid immunity being superior, as compared with either vaccine-induced (without a booster) immunity or natural immunity alone. Timing and mode of vaccination of previously infected individuals to achieve optimal hybrid immunity are central questions that remain to be addressed in future studies.

Given that vaccination rates are continuously increasing and that, by the beginning of 2022, perhaps half or more of the global population had already been infected with SARS-CoV-2, with the vast majority of this group not being officially detected, it would appear logical that future infection waves, even with highly transmissible variants of SARS-CoV-2, may be limited with respect to their maximum potential health burden. The advent of Omicron suggests that massive surges can occur even in populations with extremely high rates of previous vaccination and variable rates of prior infections. However, even then, the accompanying burden of hospitalizations and deaths is far less than what was seen in 2020 and 2021. One may argue that the pandemic has already transitioned to the endemic phase and that Omicron is an endemic wave occurring in the setting of already widespread population immunity.

A version of this article first appeared on Medscape.com.

Seroprevalence surveys suggest that, from the beginning of the pandemic to 2022, more than a third of the global population had been infected with SARS-CoV-2. As large numbers of people continue to be infected, the efficacy and duration of natural immunity, in terms of protection against SARS-CoV-2 reinfections and severe disease, are of crucial significance. The virus’s epidemiologic trajectory will be influenced by the trends in vaccine-induced and hybrid immunity.

Omicron’s immune evasion

Cases of SARS-CoV-2 reinfection are increasing around the world. According to data from the U.K. Health Security Agency, 650,000 people in England have been infected twice, and most of them were reinfected in the past 2 months. Before mid-November 2021, reinfections accounted for about 1% of reported cases, but the rate has now increased to around 10%. The reinfection risk was 16 times higher between mid-December 2021 and early January 2022. Experts believe that this spike in reinfections is related to the spread of Omicron, which overtook Delta as the dominant variant. Nonetheless, other aspects should also be considered.

Omicron’s greater propensity to spread is not unrelated to its ability to evade the body’s immune defenses. This aspect was raised in a letter recently published in the New England Journal of Medicine. The authors reported that the effectiveness of previous infection in preventing reinfection against the Alpha, Beta, and Delta variants was around 90%, but it was only 56% against Omicron.
 

Natural immunity

Natural immunity showed roughly similar effectiveness regarding protection against reinfection across different SARS-CoV-2 variants, with the exception of the Omicron variant. The risk of hospitalization and death was also reduced in SARS-CoV-2 reinfections versus primary infections. Observational studies indicate that natural immunity may offer equal or greater protection against SARS-CoV-2 infections, compared with immunization with two doses of an mRNA vaccine, but the data are not fully consistent.

Natural immunity seems to be relatively long-lasting. Data from Denmark and Austria show no evidence that protection against reinfections wanes after 6 months. Some investigations indicate that protection against reinfection is lowest 4-5 months after initial infection and increases thereafter, a finding that might hypothetically be explained by persistent viral shedding; that is, misclassification of prolonged SARS-CoV-2 infections as reinfections. While no comparison was made against information pertaining to unvaccinated, not previously-infected individuals, preliminary data from Israel suggest that protection from reinfection can decrease from 6 to more than 12 months after the first SARS-CoV-2 infection. Taken together, epidemiologic studies indicate that protection against reinfections by natural immunity lasts over 1 year with only moderate, if any, decline over this period. Among older individuals, immunocompromised patients, and those with certain comorbidities or exposure risk (for example, health care workers), rates of reinfection may be higher. It is plausible that reinfection risk may be a function of exposure risk.

There is accumulating evidence that reinfections may be significantly less severe than primary infections with SARS-CoV-2. Reduced clinical severity of SARS-CoV-2 reinfections naturally also makes sense from a biologic point of view, inasmuch as a previously primed immune system should be better prepared for a rechallenge with this virus.
 

Vaccine-induced immunity

The short-term (<4 months) efficacy of mRNA vaccines against SARS-CoV-2 is high and varies from 94.1% (Moderna) to 95% (BioNTech/Pfizer). This has been confirmed by randomized controlled trials and was subsequently confirmed in effectiveness studies in real-world settings. Waning efficacy was observed with respect to protection against SARS-CoV-2 infections (for example, only approximately 20% after about half a year in Qatar), whereas protection against severe disease was either sustained or showed only a moderate decline.

In individuals who received two doses of the BioNTech/Pfizer vaccine at least 5 months earlier, an additional vaccine dose, a so-called booster, significantly lowered mortality and severe illness. These findings suggest that the booster restored and probably exceeded the initial short-term efficacy of the initial vaccination.

Data are still emerging regarding the efficacy of boosters against the Omicron variants. Preliminary data suggest a far lower ability to restore protection from infection and vaccination. However, fatalities and hospitalizations remain low.
 

Natural immunity vs. vaccine-induced immunity

Comparisons of natural immunity with vaccine-induced immunity are complicated by a series of biases and by combinations of biases – for example, the biases of comparisons between infected and uninfected, plus the biases of comparisons between vaccinated and nonvaccinated, with strong potential selection biases and confounding. Of particular note, the proportion of people previously infected and/or vaccinated may influence estimates of effectiveness. Regarding this point, one study compared unvaccinated patients with a prior SARS-CoV-2 infection and vaccinated individuals followed up from a week after the second vaccine dose onward versus a group of unvaccinated, not previously infected individuals. The findings showed that, compared with unvaccinated, not previously infected individuals, the natural immunity group and the vaccinated group had similar protection of 94.8% and 92.8% against infection, of 94.1% and 94.2% against hospitalization, and of 96.4% and 94.4% against severe illness, respectively.

Hybrid immunity

The combination of a previous SARS-CoV-2 infection and a respective vaccination is called hybrid immunity. This combination seems to confer the greatest protection against SARS-CoV-2 infections, but several knowledge gaps remain regarding this issue.

Data from Israel showed that, when the time since the last immunity-conferring event (either primary infection or vaccination) was the same, the rates of SARS-CoV-2 infections were similar in the following groups: individuals who had a previous infection and no vaccination, individuals who had an infection and were then vaccinated with a single dose after at least 3 months, and individuals who were vaccinated (two doses) and then infected. Severe disease was relatively rare overall.

Data on the efficacy of hybrid immunity point in the direction of hybrid immunity being superior, as compared with either vaccine-induced (without a booster) immunity or natural immunity alone. Timing and mode of vaccination of previously infected individuals to achieve optimal hybrid immunity are central questions that remain to be addressed in future studies.

Given that vaccination rates are continuously increasing and that, by the beginning of 2022, perhaps half or more of the global population had already been infected with SARS-CoV-2, with the vast majority of this group not being officially detected, it would appear logical that future infection waves, even with highly transmissible variants of SARS-CoV-2, may be limited with respect to their maximum potential health burden. The advent of Omicron suggests that massive surges can occur even in populations with extremely high rates of previous vaccination and variable rates of prior infections. However, even then, the accompanying burden of hospitalizations and deaths is far less than what was seen in 2020 and 2021. One may argue that the pandemic has already transitioned to the endemic phase and that Omicron is an endemic wave occurring in the setting of already widespread population immunity.

A version of this article first appeared on Medscape.com.