The U.S. Food and Drug Administration (FDA) is preparing to allow “mix and match” coronavirus vaccine boosting, in which people get a different additional shot to the dose they initially received, U.S. media reported.
Citing sources familiar with the situation, the New York Times said the FDA might make the announcement on Wednesday when it is also expected to authorise boosters for the Moderna and Johnson & Johnson vaccines.
A preliminary study showed that people who have received the J&J vaccine may benefit from a booster dose of a different, messenger-RNA vaccine such as Pfizer or Moderna.
But multiple reports quoted people familiar with the discussions as saying one shot may not be recommended over another.
“People should generally get the same vaccine as their initial series,” a federal official told the Washington Post.
Proponents of mixing and matching point to its benefits in terms of simplifying vaccine rollout, and ensuring those who need boosters can get them regardless of which jab they initially had. “From a public health perspective, there’s a clear need in some situations for individuals to receive a different vaccine,” Amanda Cohn, a Centers for Disease Control and Prevention official, told the New York Times.
In July, the World Health Organization’s chief scientist Soumya Swaminathan said mixing and matching vaccines was “a bit of a data-free, evidence-free zone.”
The U.S. study on boosters has several limitations. The number of participants was small, and the immune response could evolve beyond the 15 days observed during the study.
