According to data from the first study to assess how the retooled shots are faring in the real world, 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.
The findings back up findings from company studies showing that their updated shots produced higher antibody responses against the BA.4/B.5 subvariants after one month than their original shots. more info
More than 360,000 people participated in the study, which compared updated boosters from Pfizer/BioNTech and Moderna that target both the original virus and Omicron BA.4/5 coronavirus subvariants with their previous COVID-19 vaccines. The findings were published in the Morbidity and Mortality Weekly publication of the Centers for Disease Control and Prevention in the United States.
The new shots were approved in the United States in September based on human trials of vaccines that included an earlier Omicron variant, as well as data on the BA.4/BA.5 boosters from lab and animal studies.
The most recent study found that the vaccines were more beneficial to people aged 18 to 49 than to older people.
The study found that when given eight months or more after a previous COVID shot, the new boosters were 56% more effective than the original shots in preventing symptomatic disease in people aged 18-49 years, 48% in those aged 50-64 years, and 43% in those aged 65 and older.
When boosters were administered two to three months after previous vaccination, vaccine effectiveness dropped to a range of 28%-31%.
The study’s authors noted several limitations, including the possibility that participants did not accurately recall their vaccination status, previous infection history, and underlying medical conditions, as well as the possibility that low acceptance of the new boosters skewed the results.
According to data from the United States, approximately 35 million updated boosters have been administered across the country, representing approximately 10% of the total population.
Furthermore, the results may not be generalizable to future variants because the dominant variants are constantly evolving, according to the authors.
In just the last two months, the BQ.1 and BQ.1.1 subvariants of the coronavirus have surpassed the BA.5 subvariant of Omicron targeted by the updated boosters to become the dominant versions of the coronavirus in the United States.
(Adapted from Reuters.com)