CDC advises a booster once you’re well, but some doctors suggest waiting a little longer.
If you just tested positive for COVID-19 but haven’t been boosted yet, should you run to your local pharmacy and get a booster shot once you’re well? After all, a number of universities and employers across the country are requiring proof of boosters before you can return to campus—or the office.
The official guidance from the Centers for Disease Control and Prevention (CDC) is to get your booster as soon as you’re done isolating (a recommended five full days) and your symptoms have improved, meaning you have been fever-free for 24 hours.
Yet, based on anecdotal reports, some doctors are advising people to hold off for some period of time—30, 60, or even 90 days—before getting a boost. So how should you navigate a booster mandate if you just had COVID? And which is safer: boosting ASAP or holding off a month or two post infection?
We asked experts to parse out what we know so far about booster shots after a breakthrough infection.
Do you really need a booster after a COVID breakthrough infection?
First, let’s look at the rationale for boosting. “I always like to remind people what the word ‘booster’ means,” says Michael Bauer, MD, medical director at Northwestern Medicine Lake Forest Hospital in Lake Forest, Illinois. “It reminds your immune system to rev up again [to produce more antibodies],” he tells Health.
“If you’ve been vaccinated and then get a COVID infection, that infection is actually serving a similar role to a booster,” explains Dr. Bauer. “In effect, you are getting a booster at that point by natural immunity.”
The question is, how long does that immunity last?
Data from earlier in the pandemic suggest that people are unlikely to get reinfected right away. One study, published in JAMA Internal Medicine, looked at folks who had COVID-19 (confirmed by an antibody test) on or after January 2020. Researchers followed those people over time. The likelihood of getting another COVID infection within 90 days was exceedingly low.
That’s because we develop antibodies to help fight off the virus, according to Dr. Bauer.
But now that Omicron is the dominant variant in the US, it’s unclear how protective a prior infection may be against future bouts of COVID. Frankly, experts say, there’s a dearth of data.
A preprint study (which has yet to undergo peer review) examined COVID reinfections in South Africa. Based on population data, researchers found evidence suggesting that Omicron is able to escape immunity from prior infection. Separately, a report from the Imperial College London (also not yet peer reviewed) estimated that the risk of reinfection is 5.4 times greater with Omicron compared with Delta.
“I think one of the problems with natural infection is that the antibody responses that you’re going to get, and the immune responses that you are left with after natural infection, can be variable,” says Jonathan Li, MD, associate professor of medicine at Harvard Medical School and a member of the NIH COVID-19 Treatment Guidelines Panel.
“We just don’t know how well that recent infection is going to protect that individual against subsequent infection, whereas a booster is standardized,” Dr. Li told Health during a media briefing on COVID. Vaccinations (including boosters) are also a “more reliable means of offering longer-term protection,” he noted.
Who’s eligible for a booster after having COVID?
Adults and some adolescents are eligible for booster doses. Here’s how the CDC breaks out its booster guidance:
If you got the Pfizer-BioNTech vaccine, you can get a booster at least five months after completing that series. Adults (18 and older) can decide which booster to get, though Pfizer and Moderna boosters are preferred in most situations, per the CDC. Teens 12 to 17 may get the Pfizer booster.
Adults 18 and older who got Moderna can get boosted five months after completing that series. Again, a Pfizer or Moderna booster is preferred in most cases.
And anyone 18 and older who got the Johnson & Johnson (J&J)/Janssen vaccine is due for a booster two months after that shot. In most cases, Pfizer and Moderna are preferred, although the CDC describes specific situations in which another J&J jab may be considered, say, if someone has a severe allergy to one of the Pfizer or Moderna vaccine ingredients.
What if you are required to get a booster even though you had a recent COVID infection?
Per CDC guidance, people who had COVID before getting their booster dose should go ahead and get that extra jab after their isolation period is over.
“The CDC says there’s no definite interval that you need wait after you have recovered from your acute illness to get your booster dose,” William Schaffner, MD, professor of medicine in the Division of Infectious Diseases at Vanderbilt University School of Medicine in Nashville, tells Health.
His preference? “I would give them the vaccine, sure, because we think that there’s no discernible safety issue, and they may well benefit from getting that booster.”
Age isn’t a factor either, says Michael Chang, MD, a pediatric infectious disease physician with McGovern Medical School at UTHealth Houston and Children’s Memorial Hermann Hospital. “As long as you’re eligible for the vaccine and booster, the guidance is the same.”
Dr. Chang suggests scheduling your booster while you’re in isolation. “Ultimately, you should have a minimum disruption of six days—a minimum of five days in isolation and then a booster the next day.”
What if you want to wait a bit before getting boosted?
“A lot of doctors will tell patients that if you’re vaccinated and just recovering from a COVID infection, it makes sense to wait 30 to 60 days or so since you are already protected,” says Dr. Bauer.
With Omicron, though, there’s “a lack of clear data” to advocate for getting boosted right away after a COVID infection versus waiting it out, notes Aaron E. Glatt, MD, chair of the Department of Medicine and chief of Infectious Diseases at Mount Sinai South Nassau on New York’s Long Island.
“If I’m asked my professional medical opinion, I say we really don’t have a lot of data. We tend to wait 90 days,” Dr. Glatt tells Health.
That said, if you require a booster for work or travel or some other reason, “I don’t think it’s dangerous to take the vaccine,” adds Dr. Glatt.