A highly anticipated study of “mixing and matching” Covid-19 vaccines found the approach to be safe and effective, although the Moderna and Pfizer-BioNTech vaccines were found to spark stronger immune system responses than Johnson & Johnson’s vaccine.
“Mixing and matching” refers to giving a booster dose of a vaccine different from the vaccine type that was used for the initial vaccination series.
The National Institutes of Health study, which was released Wednesday but has yet to be peer-reviewed, found that people who received the Johnson & Johnson vaccine produced stronger antibody levels after they got booster shots made by Moderna or Pfizer, compared to boosters from Johnson & Johnson. Those who were originally vaccinated with the Pfizer or Moderna vaccines and received either company’s booster shot produced similarly strong immune responses, the researchers found.
CDC recommends that certain populations receive a booster shot of Pfizer-BioNTech’s #COVID19 Vaccine at least 6 months after completion of their 2-dose Pfizer-BioNTech vaccine series.
— CDC (@CDCgov) September 24, 2021
The findings will be presented Friday to the Food and Drug Administration’s advisory committee. The group is meeting Thursday and Friday to consider recommending the emergency use authorization of booster shots of the Moderna and Johnson & Johnson vaccines.
Moderna and Johnson & Johnson release documents about COVID vaccine boosters https://t.co/swdOGwpA3Z
— NPR Health News (@NPRHealth) October 12, 2021
Study participants were divided into groups based on their original immunizations and were given one of three boosters made by Pfizer, Moderna, or Johnson & Johnson. For instance, those who were originally vaccinated with Pfizer’s two-dose regimen got matching Pfizer boosters or “mixed” boosters from either Moderna or Johnson & Johnson. The study also assessed full doses of each vaccine even though Moderna is seeking authorization from the FDA for a half-dose booster.
Friday just in: +1.12M doses reported administered over yesterdays total! Includes 306K newly vaccinated and 520K additional doses/boosters. The US vaccination program has now administered over 400 million COVID-19 vaccine doses, truly a historic national team effort. 🇺🇸
— Cyrus Shahpar (@cyrusshahpar46) October 8, 2021
Antibody levels in people who were originally vaccinated with Johnson & Johnson’s single-shot were about five times higher after they received matching Johnson & Johnson boosters. Those who originally received Johnson & Johnson’s vaccine but were given boosters of either the Pfizer or Moderna vaccines had significantly stronger immune responses, including antibody levels that were more than 50 times higher after the Moderna booster.