COVID Vax Immunity Wanes After a ‘Few Months’: The New England Journal of Medicine

“These findings indicate that immunity against the delta variant of SARS-CoV-2 waned in all age groups a few months after receipt of the second dose of vaccine.”

QUICK FACTS:
  • A recent study published in The New England Journal of Medicine and conducted in Israel found that immunity against the delta variant of SARS-CoV-2 waned in all age groups only a few months after receipt of the second vaccine dose.
  • The study researchers used data on “confirmed infection and severe disease collected from an Israeli national database for the period of July 11 to 31, 2021, for all Israeli residents who had been fully vaccinated before June 2021,” according to the publication.
  • Researchers compared rates of confirmed coronavirus infections and severe infection among “persons vaccinated during different time periods, with stratification according to age group and with adjustment for possible confounding factors.”
  • The researchers conclude, “These findings indicate that immunity against the delta variant of SARS-CoV-2 waned in all age groups a few months after receipt of the second dose of vaccine.”
  • The researchers also conclude the findings suggest the need to “follow the effects of waning immunity closely” as well as the need to “inform policymakers worldwide who are facing decisions regarding the administration of booster vaccinations.”
Figure 1. Daily Confirmed SARS-CoV-2 Infections and New Cases of Severe Covid-19 among Fully Vaccinated Persons in Israel, June through Early August 2021. The graph shows increases in the numbers of daily severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and new cases of severe coronavirus disease 2019 (Covid-19), on different scales, during the delta variant wave among persons who had received two doses of vaccine.
STUDY RESULTS:

Among persons 60 years of age or older, the rate of infection in the July 11–31 period was higher among persons who became fully vaccinated in January 2021 (when they were first eligible) than among those fully vaccinated 2 months later, in March (rate ratio, 1.6; 95% confidence interval [CI], 1.3 to 2.0). Among persons 40 to 59 years of age, the rate ratio for infection among those fully vaccinated in February (when they were first eligible), as compared with 2 months later, in April, was 1.7 (95% CI, 1.4 to 2.1). Among persons 16 to 39 years of age, the rate ratio for infection among those fully vaccinated in March (when they were first eligible), as compared with 2 months later, in May, was 1.6 (95% CI, 1.3 to 2.0). The rate ratio for severe disease among persons fully vaccinated in the month when they were first eligible, as compared with those fully vaccinated in March, was 1.8 (95% CI, 1.1 to 2.9) among persons 60 years of age or older and 2.2 (95% CI, 0.6 to 7.7) among those 40 to 59 years of age; owing to small numbers, the rate ratio could not be calculated among persons 16 to 39 years of age.

Jon Fleetwood is Managing Editor for American Faith and author of “An American Revival: Why American Christianity Is Failing & How to Fix It.“