Jeanne got her second COVID booster shot Monday, March 21. Though she was two years out from a mastectomy to treat breast cancer, her health status did not make her eligible for this fourth vaccine dose. (We are using her first name only to protect her family’s privacy.) So she did what at least a few Americans have done since the vaccines were released to the public: She stretched her interpretation of the vaccine eligibility guidelines a bit to get an appointment at CVS.
Vaccine manufacturers have been bullish about boosters. Moderna has requested that the Food and Drug Administration authorize a fourth shot for all adults, and the CEO of Pfizer has said that a fourth dose will be needed for all adults. So far, the Centers for Disease Control and Prevention has only recommended a second booster shot for some immunocompromised people, though the FDA is expected to authorize the shot for adults over 50 next week. [Update, March 29, 2022: The FDA has authorized them.] At the same time, scientists are urging Americans to prepare for the possibility of another wave of COVID, driven by BA.2. So should otherwise healthy adults be eagerly awaiting the approval of a fourth shot? And is there anything to be gained in fibbing a little to sneak in ahead?
There were a few factors that went into Jeanne’s decision to do just that. Part of it was that she wanted to protect herself against long COVID. She also wanted to protect the people around her, as she lives and works around people who smoke and have chronic obstructive pulmonary disease, a group that is at higher risk of serious complications from COVID. Further, she’s worried that people are getting complacent as the pandemic continues. “It’s just we’re at a crossroads with it, politically, and I don’t know which direction we’re going to be going, and so I’m just trying to do whatever little bit I can do to protect myself,” Jeanne explained.
It’s currently unclear just how beneficial more boosters would be for healthy adults, as data is limited. A preprint out of Israel showed decreased rates of infection and severe illness in people 60 and older after a fourth dose of the Pfizer vaccine. A Morbidity and Mortality Weekly Report published by the CDC showed that about four months after a third dose of an mRNA vaccine, the vaccine effectiveness rate in preventing urgent care hospitalizations was 78 percent for adults, suggesting some waning immunity (though the data did not separate high-risk from low-risk adults).
Vaccines, as safe as they are, can come with side effects, which is exactly why the FDA and CDC can take time to approve them for particular groups of people. Dr. Gregory Poland, the director of the Mayo Clinic’s vaccine research group, stressed the importance of weighing the risks and the benefits of additional vaccinations. He told me that after his second dose, he developed tinnitus that hasn’t ceased since. Poland was clear that a link between the condition and vaccination hasn’t been proven. An NBC News report on Poland’s case by reporter Erika Edwards notes that COVID itself has been linked to a worsening of tinnitus; getting the vaccine is the best way to reduce risk against the condition. But it’s reason enough for Poland to be very cautious about advising additional booster doses of the vaccine. “If there was a correlation between getting that [extra] vaccine and a lifelong, 24/7 ringing in your ears, would you say, ‘I’m willing to risk a lifelong condition in order to prevent an asymptomatic or mild case of COVID-19’? I doubt you’d make that trade-off,” he says. For a less extreme example, if you’re an otherwise healthy adult at low risk from COVID, it could be worth considering that side effects from another shot might make you miss a day of work. However, for an older adult who is more at risk of serious complications from COVID, that risk might be worth it.
There’s another reason to hold off on the second booster: The currently available vaccines are still tailored to the ancestral strain of SARS-CoV-2, Poland reminded me. Poland didn’t use this exact example, but imagine you were trained to fight off a black bear, so that when you encounter a black bear, you’ll be pretty good at dealing with it. In fact, you take two black bear fighting classes—the vaccines are the training, in this metaphor—to get even better. Now, the third time you’re trained, you get really good at fighting black bears. But now the bear population has changed—it’s mostly grizzly bears now (bears are variants in this metaphor). You’ll be able to carry some bear knowledge over, but the grizzly will have some tricks up its sleeve that the black bear won’t. Now, you’ve been given an opportunity to sneak into yet another class on black bear combat, but how much more value will you get out of that black bear training class? Especially when there’s news of a spike in polar bears? Put another way: More boosters may offer diminishing returns.
Another expert I checked with, though, was a little more in favor of a second booster—at least, once vaccine manufacturers have released more information. Dr. Peter Hotez, a professor at Baylor College of Medicine and co-director of the Texas Children’s Hospital Center for Vaccine Development, said that when that safety data comes out, barring any unexpected complications, he does support a second booster, citing the CDC report showing waning immunity and the Israeli preprint indicating the benefits of a second booster. “I’m a proponent of getting second [boosters], but I present it with a very strong asterisk, saying I’ve not seen the safety data, and that’s why I can’t give you a robust recommendation,” said Hotez.
He also acknowledged that it is hard to make an exact call right now: “This has been the story of trying to do this in the middle of a raging pandemic—trying to make the best decision you can with the data that you have and the data that you’ve collected during the pandemic.” That’s especially true for people like Jeanne, who don’t fall neatly into one risk category or another and feel the need to protect themselves and their loved ones as best they can.