Over the past week, there’s been plenty of back-and-forth among experts about whether people need Covid booster shots — but the conversation is missing a crucial element.
On Wednesday, Pfizer submitted data to the Food and Drug Administration from a real-world study in Israel, showing that a third dose of the mRNA vaccine administered six months after a second shot restores protection from infection to 95%. That seems like solid stat to justify giving out boosters, but it omits a key point about vaccines: They’re not meant to completely prevent infection.
The Covid vaccines are doing exactly what they’re designed to do, which is to prevent hospitalizations, severe infections and deaths.
That’s one potential reason for the FDA‘s quick response to Pfizer’s report. “[The] FDA has not independently reviewed or verified the underlying data or their conclusions,” the agency wrote in a document published Wednesday. The FDA’s vaccine advisory committee is set to meet on Sept. 17 to review the data and make a decision about whether to approve booster shots in the U.S.
In its report, the FDA also noted that the Israel study submitted by Pfizer is observational, and therefore may contain biases that make the findings less reliable. Studies conducted in the U.S., the agency wrote, “may most accurately represent vaccine effectiveness in the U.S. population.”
Moderna also released new data on Wednesday ahead of the FDA committee’s meeting, claiming breakthrough cases are less frequent in people who recently received its vaccine, implying that its protection also wanes over time. The drugmaker’s analysis has yet to be peer-reviewed.
New data released last Friday bolsters the fact that the vaccines are still working as intended, even amid the spread of the more contagious delta variant. The Centers for Disease Control and Prevention studied more than 600,000 COVID-19 cases from April through mid-July, when delta became dominant, and found that unvaccinated people were about four and a half times more likely to get Covid, over 10 times more likely to be hospitalized and 11 times more likely to die from the disease.
Over time, Covid vaccines may not work as well at preventing mild illnesses in vaccinated people, “but this isn’t a sign that the vaccines are failing,” Dr. Anna Durbin, director of the Center for Immunization Research at Johns Hopkins Bloomberg School of Public Health, said during a briefing Wednesday.
That’s also why a group of experts published a piece in the medical journal The Lancet on Monday, arguing that Covid boosters are “not appropriate at this stage in the pandemic.”
Even if the FDA approves the use of boosters, deeming them safe and effective at doing what they’re supposed to do, it’s up to the CDC to review, officially sign off and decide who should get them, Durbin said.