On August 31, FDA amended the EUAs of the Moderna and Pfizer-BioNTech vaccines to authorize bivalent formulations to be used as booster doses as least two months following previous primary or booster vaccination. On September 1, ACIP discussed and voted to recommend the bivalent COVID vaccines, followed by a CDC recommendation. The updated COVID-19 boosters add Omicron BA.4 and BA.5 spike protein components to the mRNA COVID-19 vaccine composition, increasing protection against the currently circulating variants. With these updates, the original vaccine formulas are now no longer approved to be used as booster doses. CDC has updated the interim clinical considerations.

With the update of the booster vaccines, CDC has updated what it means to be up to date with COVID vaccines. It is now defined as having completed a primary series and received the most recent booster dose recommended for an individual by CDC. Recommendations vary by age, initial vaccine received, time since last dose, and for those who are immunocompromised. CDC has a tool that can help to determine when people should receive a booster dose.

With the new booster dose recommendations, the Public Health Communications Collaborative has updated its booster dose messaging toolkit. This includes topline messages, answers to tough questions, and social media posts and shareable graphics.