https://www.yalemedicine.org/news/johnson-and-johnson-covid-booster
4. If you had the J&J shot, can you get a booster of Pfizer or Moderna instead?
The FDA’s authorization of the mix-and-match approach follows a report of early data from a federal clinical trial suggested it might be better for J&J recipients to get an mRNA vaccine booster (from Pfizer or Moderna). The trial’s preliminary data showed that people who had gotten the J&J vaccine followed by a Moderna booster had a 76-fold rise in antibodies in 15 days; those who got Pfizer saw a 35-fold increase; while those who got the J&J booster had only a four-fold increase. That data was published in a preprint and has not yet undergone independent peer review.
