Updated COVID boosters offer better protection than Reuters’ original US study
(Reuters) – Updated COVID-19 boosters offer increased protection against new coronavirus subvariants in people who have previously received up to four doses of the older vaccine, based on data from the first study to assess how those upgraded are doing Vaccinations are hitting the real world, U.S. officials said Tuesday.
The results support results from company studies showing that their updated vaccinations elicited higher antibody responses against the BA.4/B.5 subvariants than their original vaccinations at one month.
The study of more than 360,000 people compared updated Pfizer/BioNTech and Moderna (NASDAQ:) boosters targeting both the original virus and subvariants of the Omicron BA.4/5 coronavirus to their previous COVID-19 vaccines. The data were published in the US Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report.
The new vaccines were launched in the United States in September after they were developed based on human studies of vaccines containing an earlier Omicron variant and data on the BA.4/BA.5 boosters from laboratory and human studies animals were allowed.
The latest study showed that the vaccines provided greater benefit to 18- to 49-year-olds than older adults.
When given eight months or more after a previous COVID vaccination, the relative vaccine efficacy of the new boosters compared to the original vaccinations in preventing symptomatic disease was 56% in people aged 18-49 years, 48% in those 50-64 year olds and 43% in people aged 65 and over, the study showed.
Vaccine efficacy dropped to a range of 28% to 31% when the booster was given just two to three months after the previous vaccination.
The study authors noted several limitations, including that participants may not have accurately recalled their vaccination status, past infection history, and underlying medical conditions, and that low uptake of the new booster shots may have skewed the results.
To date, about 35 million updated booster shots have been administered in the United States, accounting for about 10% of the total population, US data shows.
In addition, the results may not generalize to future variants as the dominant variants continue to evolve, the authors said.
In the last two months alone, the BQ.1 and BQ.1.1 subvariants have become the dominant versions of the coronavirus in the United States, overtaking Omicron’s BA.5 subvariant, which has been targeted by the updated boosters.