Do fully vaccinated people who had COVID need a booster? Here’s what experts say
COVID-19 booster shots are now available for certain fully vaccinated people after evidence revealed the initial series of shots — two doses for the Pfizer and Moderna vaccines, and one dose for the Johnson & Johnson vaccine — appear less effective against the delta variant as protection wanes over time.
Older adults, people with weakened immune systems and those at high risk of COVID-19 exposure are the most likely to benefit from a booster dose, experts say.
The benefit for people outside these groups, however, is “marginal and may amount to just pushing an inevitable breakthrough infection into the future,” Dr. Amesh Adalja, senior scholar with the Johns Hopkins Center for Health Security, told McClatchy News.
But what about the healthy, fully vaccinated people who’ve already had COVID-19 either before or after they received their shots?
Some experts point to early studies that show a prior coronavirus infection acts as a booster when coupled with complete vaccination.
Others say there’s not enough data to know for sure.
“I think there is good reason to think that those with prior infection whose immunity is topped off with vaccination likely have very robust protection and would benefit little from a booster dose,” Adalja said. “However, there may be higher risk individuals in this subgroup that would benefit from heightened protection,” including people with cancer, HIV, obesity or diabetes.
Dr. Paul Offit, a member of the U.S. Food and Drug Administration’s advisory panel on vaccines, told The Wall Street Journal fully vaccinated people who had COVID-19 “just won the game. I wouldn’t ask them to get a booster dose. I think they just got it” with their coronavirus infection.
A Centers for Disease Control and Prevention study found unvaccinated people with prior coronavirus infection were two times more likely to be reinfected compared to those who were fully vaccinated.
Research published in April showed people who were previously infected with the coronavirus had a 10-fold boost in their preexisting antibodies after two doses of the Pfizer vaccine, “but not to levels significantly higher than those of uninfected vaccinees.”
Still, understanding how protection from infection interacts with vaccine-induced protection remains largely unclear.
“We know that having COVID-19 can elicit an increase in antibodies that protect you from reinfection with the virus, so there’s likely some time in which natural immunity can act as a ‘booster,’” Dr. Dirk Sostman, chief academic officer of Houston Methodist in Texas, said in a blog post. “In addition, there is some data suggesting that COVID-19 infection followed by vaccination may provide extremely strong immunity, but we just do not have enough data to know whether this can substitute for a vaccine booster shot.”
Research from the U.K. shows two doses of the Pfizer vaccine provide 87% protection against COVID-19 infection, while unvaccinated people who have had COVID-19 only benefit from 65% protection.
However, complete vaccination plus past coronavirus infection provided 95% protection.
“If you’re not yet eligible for a booster, but have had a previous infection and two vaccines, I wouldn’t be too worried as your protection will be very high,” Tim Spector, lead scientist with the ZOE COVID Study app where people self-report COVID-19 symptoms and test results, said in an October news release. “It’s important we focus on the number of high-risk people who remain unvaccinated, which is still too high.”
Dr. Akiko Iwasaki, an immunologist at Yale University, agrees.
She told The Journal that fully vaccinated people who have had COVID-19 “are likely to be the last group that really needs the booster because they really had three exposures.”
More than 194 million people in the U.S. are fully vaccinated as of Nov. 9, according to a CDC tracker, including more than 24.7 million who have received a booster dose.
This story was originally published November 9, 2021 at 3:18 PM with the headline "Do fully vaccinated people who had COVID need a booster? Here’s what experts say."
