Most healthy, fully vaccinated Americans don’t need a Covid-19 booster shot just yet, according to a new analysis by international scientists. After reviewing the latest data on vaccine potency and durability, the team concluded most vaccines are still highly effective at preventing infections and hospitalization, despite the spread of the Delta variant.
"Even in populations with fairly high vaccination rates, the unvaccinated are still the major drivers of transmission" at this stage of the pandemic, according to an academic commentary piece authored by 18 scientists published in The Lancet on September 13. The team of collaborators includes two outgoing FDA regulators and additional leading vaccines researchers from around the world, according to the Associated Press.
The news comes in contrast to the Biden administration’s recent announcement planning to offer booster shots eight months after individuals received their second doses. Though experts agree with the decision to offer a third dose of the mRNA-based Pfizer-BioNTech and Moderna vaccines to certain people with weakened immune systems this fall, they say the general population might not need boosters as early as many suspected.
The debate over booster shots has been fueled by reports of breakthrough infections in fully vaccinated people, and the United States isn’t the only wealthy nation grappling with how and when to make a third dose available to the general public. The World Health Organization (WHO) has advised some countries to halt the rollout of booster shots until lower-income nations have access to first doses.
The recent CDC study found that unvaccinated people are around five times more likely to contract Covid-19 and up to 11 times more likely to die once they get the virus. Elderly individuals over 75 years old that vaccines show some weakening in protection against hospitalization, reports Apoorva Mandavilli for the New York Times.
“None of these studies has provided credible evidence of substantially declining protection against severe disease,” the group writes.
The review emphasizes that a drop in antibody levels doesn’t necessarily mean a proportional drop in protection. Instead of giving the same mRNA shot a third time, the group suggests boosters could be tweaked to better handle new variants as the emerge, similar the annual flu shot. A committee of FDA officials is planning to meet on September 17 to review the data.
Despite their conclusion, the authors say boosters will likely be needed eventually, reports Andrew Joseph for STAT News. But promoting the third jab too early could backfire if it’s not needed, or if it causes side effects.
“If unnecessary boosting causes significant adverse reactions, there could be implications for vaccine acceptance that go beyond Covid-19 vaccines,” the authors state.