Over the past week, there's been plenty of back-and-forth among experts about whether people need Covid booster shots — but one crucial element is getting lost in the conversation.
If you're on team booster shot or not, or if you don't know what to think, remember this: Being fully vaccinated is still preventing hospitalization in 86% of patients and death in 82%, according to the Centers for Disease Control and Prevention. In other words, even amid the spread of the contagious delta variant, the Covid vaccines are doing exactly what they're designed to do.
Much like the flu shot, Covid vaccines are intended to lower your chance of infection and severe illness, not eradicate it.
"Vaccines are designed to prevent serious illness, not to prevent infection or prevent any symptoms," 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 one potential reason for the FDA remaining neutral in the face of new Pfizer data suggesting boosters do boost immunity.
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%.
"[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 Wednesday, saying 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.
The vaccines remaining effective against hospitalization and death is also the reason 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."
And as the booster debate rages, the CDC released new data Friday bolstering the fact that the vaccines are still working as intended.
The agency 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, again: "[T]his isn't a sign that the vaccines are failing," Durbin said.
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.
This story has been edited for clarity.