As the nation braces for another possible surge in COVID-19 activity as schools resume and cooler weather brings people indoors, vaccine advisers to the Centers for Disease Control and Prevention (CDC) today recommended two updated COVID-19 boosters that target the circulating BA.4/BA.5 Omicron subvariants.

Moving forward with the new boosters

Scientists from the companies that make the two boosters said the Omicron variant is the most distant antigenically from the original SARS-CoV-2 virus and that adding Omicron alongside the original virus in a bivalent (two-strain) vaccine has the potential to broaden protection, based on data so far. BA.4 and BA.5 share the same spike protein.

The action comes just a day after the Food and Drug Administration (FDA) authorized for emergency use bivalent boosters from Moderna and Pfizer-BioNTech. The Moderna booster was authorized for people ages 18 and older and the Pfizer booster for those ages 12 and older.

After discussions today, which included extensive presentations from CDC experts, scientists from Moderna and Pfizer, as well as comments from the public, the CDC's Advisory Committee on Immunization Practices (ACIP) passed the recommendation with 13 yes votes and 1 no vote for both boosters in separate votes.

No data from human studies yet

Several ACIP members aired reservations about the lack of clinical data specifically on the BA.4/BA.5 version of the booster, while acknowledging that waiting would delay the boosters a few more months. Clinical trials are under way, and the FDA based its EUA authorization on clinical data from the Omicron BA.1 bivalent booster, which has been approved in Europe, and preclinical data on the BA.4/BA.5 version. The updated Omicron boosters are made with the same method as earlier mRNA vaccines and contain the same antigen load.

Read more...