A vial of SARS-CoV2 COVID-19 vaccine in a medical research laboratory

Evidence does not support more than a single yearly dose of the COVID-19 bivalent booster vaccine for older adults and other groups vulnerable to severe disease, according to independent advisers to the Centers for Disease Control and Prevention.

The unanimous decision, made Friday by members of the Advisory Committee For Immunization Practices (ACIP), is notable, considering that the effectiveness of COVID-19 mRNA vaccines is thought to decline significantly at about four to six months after the shot is received. 

The news comes about a month after advisers to the Food and Drug Administration endorsed phasing out the original monovalent vaccines, and using updated bivalent vaccines for all COVID mRNA shots. Currently, the CDC recommends one updated COVID-19 booster dose about two months after receipt of an initial vaccine series.

In Friday’s meeting, ACIP also recommended that any vaccine policy remain flexible, allowing more frequent doses for people with weakened immune systems for example, according to Reuters. The CDC and FDA continue to analyze how best to update COVID-19 vaccines for efficacy against new virus variants, and have proposed a fall 2023 schedule for boosters, the news outlet reported.

About 41% of the U.S. population aged 65 years and older has received the bivalent shot, according to the CDC’s COVID data tracker. That number is bigger in U.S. nursing homes, with about 52% of residents updated, according to industry advocate LeadingAge. The organization highlighted an even more impressive 65% rate of complete and up-to-date vaccinations among its members as of Feb. 12.

Meanwhile, 16% of the entire U.S. population is complete and up to date with their COVID-19 shots, the CDC reported Feb. 23.

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