COVID questions: Which booster?
Editor’s note: This ongoing series answers questions about COVID-19 and the pandemic. If you have a question to submit, please email it to covid19update@uc.wisc.edu. See answers to previous COVID questions, and visit our COVID-19 impact site.
I had my second COVID-19 shot in late January. Which booster should I get?
People who received a full-series of an mRNA vaccine should get a booster at least 6 months after their second dose. Most of the studies done to show that boosters were safe and effective were done using the same vaccine as the original series. Currently Pfizer is approved for booster with the full original dose, while Moderna is approved with only a half-dose needed for effective boosting.
EVERYONE who received a single dose of the Janssen (J&J) vaccine needs a booster. This can be given as soon as 2 months after the original dose. There is one small study done by NIH that did show some benefit for people who received J&J vaccine to switch to a different vaccine in order to have an even great boost. However that study was done with full-dose Moderna, whereas the approved booster from Moderna is only half-dose. This decreased dose has not been studied as a booster for anyone other than original recipients of Moderna vaccines. Therefore, it seems prudent for J&J recipients to seek a full dose booster with either J&J or Pfizer vaccine.
– James Conway, Pediatric Infectious Diseases Fellowship Program Director and School of Medicine and Public Health Office of Global Health Director
If you had Covid a year ago, and had a Pfizer vaccine in April and May, is the booster necessary?
While previous infection combined with vaccines does seem to offer better protection for many individuals, the quality of the immunity after infection is quite variable. Everyone who has been previously infected is still recommended to receive vaccines.
For more on third doses and booster shots, visit the CDC website.
– James Conway, Pediatric Infectious Diseases Fellowship Program Director and School of Medicine and Public Health Office of Global Health Director
See more answers to COVID questions at news.wisc.edu/tag/covid-questions/. Also, visit our COVID-19 impact site.
