COVID boosters: Should you get a third shot, who’s eligible and when?

Written by Danielle Chiriguayo, produced by Rosalie Atkinson

The U.S. government plans to offer COVID vaccine booster shots beginning September 20. Federal regulators said late last week that they may only be able to recommend a third dose for some Pfizer recipients by that deadline. What does this leave people who got the Moderna or Johnson and Johnson vaccines? Who will get priority for those third shots?

In Israel, everyone over age 12 is already eligible for Pfizer booster shots. Israel is scheduled to formally present its research to the Food and Drug Administration as the U.S. decides how to proceed.

So far, the U.S. appears to be on track to recommend booster shots for older and immunocompromised people, according to New York Times science and global health reporter Apoorva Mandavilli. But she says the FDA still needs more data to figure out whether others will also be cleared for the extra dose. 

The Biden administration is putting pressure on the FDA and CDC to approve a booster shot, she adds.

“The administration has always said they'll follow the science. But in this case, the scientists at those agencies have not fully looked at all of the information yet,” she tells KCRW. “This is one of those cases where really I think for the first time since the Trump administration, we're seeing some conflict between the scientific community at large and the Biden administration in terms of what they think is appropriate.” 

The pressure has even prompted two top regulators at the FDA to leave the agency. Both have stated that they don’t believe boosters are really necessary for the average person. 

Infectious diseases professor Dr. Peter Chin-Hong says he’s also unclear whether a booster will help bolster COVID protections. He cites Israel’s study showing that vaccine efficacy barely dropped after six months among people ages 40-59. The efficacy did drop by more than 80% in people over 60, however.  

“You could say that let's be proactive, rather than reactive and wait for a lot of people to flood hospitals. I think it's reasonable, as a clinician, to think about really protecting that older population,” Chin-Hong says. “But for the rest of us, I mean, if you look at the data, there really isn't much of a case that we need to make for the rest of the population to get a booster shot.”

He adds, “The data is clear from the beginning of the pandemic that it's very much age-related in terms of serious disease and infection. … Every decade you go above the age of 50, you add an additional risk of mortality and serious disease.” 

In the case of immunocompromised people, Chin-Hong argues that a third booster shot might not prompt an antibody response. 

He points out that Israel’s study did include some COVID variants. But in the case of a new super variant, it’s still unclear whether booster shots would help.

Mandavilli says the fears surrounding new variants are partly driving the fervor to get booster shots approved. It’s also led to confusion, prompting people to believe that a vaccine can unilaterally prevent infection. 

“It's clear so far that even with Delta, the vaccines are preventing the vast majority of people from getting really sick,” she explains. “What the vaccines are not doing as well with Delta is preventing infections. When we say infection, we're talking about something much milder — you're not actually going to end up in the hospital. And that [is what] the vaccines don't seem to be preventing nearly as well.” 

For those who might want to get a booster just to be safe, Chin-Hong says doing so might be more trouble than it’s worth. “I can definitely understand that worry. But again, it may be a goal that’s hard to achieve because you probably would need a shot every six months.” 

He says you should have faith in science instead. “There's recent data showing that people with breakthrough vaccination cases … have much lower odds of getting long COVID or chronic symptoms by more than two times. Then you're thinking about a possible risk, but much, much lower than if you weren't vaccinated.” 



  • Dr. Peter Chin-Hong - professor of medicine who specializes in infectious diseases at the University of California San Francisco
  • Apoorva Mandavilli - science and global health reporter for the New York Times