Comparing frequency of booster vaccination to prevent severe COVID-19 by risk group in the United States

Abstract

While waning protection from vaccination and natural infection against SARS-CoV-2 infection is well-documented, recent analyses have also found waning of protection against severe COVID-19. This highlights a broader need to understand the optimal timing of COVID-19 booster vaccines specific to an individual to mitigate the risk of severe COVID-19, while accounting for waning of protection and differential risk by age group and immune status. Here we show that more frequent COVID-19 booster vaccination (every 6-12 months) in older age groups and the immunocompromised population would effectively mitigate the burden of severe COVID-19, while frequent boosters in the younger population may only provide modest benefit. Analyzing United States COVID-19 surveillance and seroprevalence data in a microsimulation model, we estimated that in persons 75+ years, annual and semiannual bivalent boosters would reduce annual absolute risk of severe COVID-19 by 311 (277-369) and 578 (494-671) cases, respectively, compared to a one-time bivalent booster dose. In contrast, for persons 18-49 years, the model estimated that annual and semiannual bivalent boosters would reduce annual absolute risk of severe COVID-19 by 20 (13-26) and 37 (24-50) cases per 100,000 persons, respectively, compared to a one-time bivalent booster dose. Persons with prior infection had a much lower benefit of more frequent boosting, while immunocompromised persons had larger benefit. This study underscores the benefit of customizing timing of COVID-19 booster vaccines based on individual risk.

Optimal annual COVID-19 vaccine boosting dates following previous booster vaccination or breakthrough infection

“…Booster vaccination has tremendous public health potential (20,42,43). However, uptake of COVID-19 booster vaccination by low proportions of residents has lowered its public health impact (26).…”

Comparative Analysis of Adverse Event Rates and Severity Following COVID-19 mRNA Vaccinations Among SARS-CoV-2 Naïve Nursing Home Residents and Staff

“…However, the estimation of the magnitude and durability of protection through COVID-19 vaccination has become a challenge because of the emergence of the omicron variants which altered virus characteristics, such as transmissibility and antigenicity, evolving in response to herd immunity 9 . A recent study reported that frequent COVID-19 booster vaccination in older age groups and the immunocompromised population would effectively reduce the burden of severe COVID-19 by analyzing COVID-19 surveillance and seroprevalence data 10 .…”