New COVID-19 vaccine boosters are coming

The Food and Drug Administration on Wednesday authorized new Covid-19 vaccines for emergency use for the first time since the original vaccines were approved in December 2020. The new boosters from Pfizer/BioNTech and from Moderna are targeted at the BA.4 and BA.5 subvariants of the omicron variant. They’re also the engine of a new vaccine booster campaign in the United States as health officials brace for another surge in cases. “As we head into fall and begin to spend more time indoors, we strongly encourage anyone who is eligible to consider receiving a booster dose with a bivalent COVID-19 vaccine to provide better protection against currently circulating variants,” said FDA Commissioner Robert M. Califf in a statement. “Bivalent” refers to the fact that the vaccines contain genetic instructions for the immune system to target the original version of the SARS-CoV-2 virus that causes Covid-19, as well as the main variants in circulation now.

The BA.4 and BA.5 subvariants are notorious for evading prior immunity to Covid-19, although older Covid-19 vaccines are still preventing hospitalizations and deaths from newer versions of the virus. Before those shots can start going into arms, the Centers for Disease Control and Prevention has to weigh in and come up with guidelines for how to distribute these new shots. Advisers to the CDC are meeting this Thursday and Friday to come up with recommendations. Meanwhile, the US government has already ordered 170 million doses. Pending CDC approval, shots could begin rolling out as soon as next week. As for who is eligible, the Moderna bivalent vaccine is available to anyone over the age of 18 as a first booster or a second booster, provided it’s been at least two months since the last shot. The Pfizer/BioNTech vaccine follows the same criteria except that it’s open to people ages 12 and up. For both boosters, it does not matter which vaccine you had as your initial doses. However, the bivalent vaccines are only authorized as boosters, so at the moment, they don’t replace the original vaccines for people who are completely unvaccinated.