If you’ve had the Johnson & Johnson vaccine, should you get a Pfizer booster to stay safe from the delta variant?

johnson & johnson booster pfizer vaccine
Photo via New York National Guard/Flickr (CC BY ND 2.0)

As the delta COVID variant continues its rapid spread, new questions are arising about the efficacy of the different COVID vaccines. People who received the Pfizer and Moderna vaccines remain confident in their level of protection, but some people that received the Johnson & Johnson single-dose vaccine are more hesitant. The rise of variants has some Johnson & Johnson recipients wondering if they’ll need a Pfizer booster shot to better protect themselves. 

The Food and Drug Administration, along with the Centers for Disease Control and Prevention, do not recommend adding to the protection granted by the Johnson & Johnson vaccine. There is not yet any data on the safety or efficacy of doing so, according to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, and no evidence yet points to a booster being necessary. 

Data suggests that the Johnson & Johnson vaccine is effective at protecting against the delta variant even without a booster. The single-shot vaccine doesn’t offer quite the level of protection that Pfizer and Moderna do, but experts say it is unnecessary to mix-and-match vaccines, particularly when Johnson & Johnson vaccine recipients are considered fully vaccinated two weeks after their single dose. 

“Right now, we have no information to suggest that you need a second shot after J&J even with the delta variant,” CDC Director Rochelle Walensky said. 

Despite this, some people are signing up to receive a Pfizer booster following a Johnson & Johnson vaccine. While this practice isn’t recommended by the CDC or FDA, it is not expected to be dangerous. Experts still advise against mixing vaccines, however, until further research is done into potential side effects and risks. 

“Are you going to get many more sore arms, rashes, feeling badly, fever, not feeling up to snuff for a day or two or even longer?” William Schaffner, medical director of the National Foundation for Infectious Diseases, said. “We don’t know how frequently that will occur, and we don’t know anything about really any other more serious adverse reactions. I think none would be expected, I would like to make that clear, it’s just that we don’t have this experience documented.”

Until health agencies conclude research into the safety of mixing vaccine doses, experts continue to advise against fully vaccinated people getting an additional shot.

Early trials indicate that a Pfizer booster shot can generate a “strong immune response” when mixed with the AstraZeneca vaccine, which shares several similarities with Johnson & Johnson’s vaccine. A British study found that volunteers who received a Pfizer booster following an AstraZeneca vaccine “produced antibody levels roughly as high as recipients of two Pfizer doses,” according to U.S. News

Read more on the delta variant: 

Sources: U.S. News, Business Insider, Washington Post

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