Evidence does not support boosters for general public, experts argue
The United States still plans to offer COVID-19 vaccine booster doses to the general public beginning Sept. 20, pending FDA approval and CDC recommendations.
However, the question remains if a third dose of messenger RNA vaccine is necessary for most people.
In a new viewpoint published in The Lancet, Philip R. Krause, MD, MS, deputy director of the FDA’s Office of Vaccines Research and Review, and experts from six other countries and WHO argued that “current evidence does not ... appear to show a need for boosting in the general population, in which efficacy against severe disease remains high.”
The authors suggest there could be risks associated with offering COVID-19 booster doses “too soon, or too frequently, especially with vaccines that can have immune-mediated side-effects (such as myocarditis, which is more common after the second dose of some mRNA vaccines, or Guillain-Barré syndrome, which has been associated with adenovirus-vectored COVID-19 vaccines)” such as the Johnson & Johnson shot.
“If unnecessary boosting causes significant adverse reactions, there could be implications for vaccine acceptance that go beyond COVID-19 vaccines,” the authors wrote. “Thus, widespread boosting should be undertaken only if there is clear evidence that it is appropriate.”
According to the authors, a consistent finding among all current evidence is that efficacy from available COVID-19 vaccines is “substantially greater” against any infection, and “substantially protective” against severe disease from all main viral variants, supporting the argument against boosters.
“Even if humoral immunity appears to wane, reductions in neutralizing antibody titer do not necessarily predict reductions in vaccine efficacy over time, and reductions in vaccine efficacy against mild disease do not necessarily predict reductions in the (typically higher) efficacy against severe disease,” they wrote.
There has not been a published study providing credible evidence of “substantially declining protection against severe disease, even when there appear to be declines over time in vaccine efficacy against symptomatic disease,” the authors wrote.
They argued that now is the time to test variant-specific vaccines “before there is widespread need for them” — a strategy similar to annual influenza vaccination.
“Any decisions about the need for boosting or timing of boosting should be based on careful analyses of adequately controlled clinical or epidemiological data, or both, indicating a persistent and meaningful reduction in severe disease, with a benefit–risk evaluation that considers the number of severe cases that boosting would be expected to prevent, along with evidence about whether a specific boosting regimen is likely to be safe and effective against currently circulating variants,” the authors wrote.