Pfizer is significantly less effective at preventing severe cases of disease over the long term
Amid persistent concerns that the protection offered by COVID-19 vaccines may be waning, a report released Friday by the Centers for Disease Control and Prevention finds that America's workhorse shot is significantly less effective at preventing severe cases of disease over the long term than many experts had realized.
Data collected from 18 states between March and August suggest the Pfizer-BioNTech vaccine reduces the risk of being hospitalized with COVID-19 by 91% in the first four months after receiving the second dose. Beyond 120 days, however, that vaccine efficacy drops to 77%. Overall, 54% of fully vaccinated Americans have been immunized with the Pfizer shot.
The surprising findings came as a Food and Drug Administration advisory panel recommended against offering booster doses of the Pfizer vaccine to all Americans ages 16 and older. In a striking rebuke, 16 of 18 experts told the agency it had not mustered enough data to make a third shot the norm.
Panel members made clear that the despite Pfizer's aggressive stance, it had not gathered enough evidence that a third shot was safe for young people and for those at lesser risk of becoming severely ill with COVID-19. "We need age-specific data" on the safety and protective benefits of a further booster, said Dr. Ofer Levy, a panel member who directs the Precision Vaccines program at Boston Children's Hospital.
And in mid-August, Biden himself said his administration would begin making booster shots available the week of Sept. 20 to those vaccinated for at least eight months.
Biden cautioned at the time that his plan was contingent on FDA approval. But his announcement stoked concerns of political meddling in a matter that required the unhindered evaluation of scientists.
Researchers in the United States have been warning for months that the immunity afforded by COVID-19 vaccines might be waning. The CDC reported that in late July, close to three-quarters of the 469 people swept up in a Massachusetts outbreak were fully vaccinated. And the agency has launched several studies aimed at detecting changes in vaccine effectiveness in healthcare workers and others who were vaccinated early. But virtually all of those infections appeared to be mild. And health officials eager to induce vaccine skeptics to step up for their shot have repeatedly praised the vaccines for keeping most fully vaccinated people out of hospitals.
The new report on waning vaccine efficacy challenges that expectation.
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