U.S. CDC advisers might recommend Omicron specific vaccine boosters

Vaccine experts will meet on Thursday to discuss updated COVID-19 boosters and make recommendations to the U.S. Centers for Disease Control and Prevention (CDC) on who should receive the shots, one of the last steps before they are rolled out as soon as this weekend.

The U.S. Food and Drug Administration on Wednesday authorized the updated shots from Pfizer/BioNTech and Moderna that target the dominant BA.4 and BA.5 Omicron subvariants as well as the original virus.

The CDC’s Advisory Committee for Immunization Practices (ACIP) will vote on a recommendation for who should receive the boosters before the agency’s Director Rochelle Walensky makes the final call after the meeting. She has generally been supportive of a booster campaign in recent public statements.

The FDA authorized the shots for people aged 12 and older who have received a primary vaccine series or have received a booster at least two months prior.

CDC officials, as well as the FDA, have indicated they believe the shots will help increase immunity against the virus ahead of the winter season when infections tend to rise as people spend more time indoors where the virus is more easily transmitted.

Currently, a second booster is restricted largely to people over age 50 and those who are immunocompromised or at high risk.

FDA officials on Wednesday said they believed the retooled shots should be available to a broader population as they may help younger people avoid long COVID, which can leave them suffering debilitating symptoms for months. Vaccine makers have yet to complete human trials for the newly authorized boosters, and ACIP members are likely to raise questions over the lack of data. Most of the available data on the redesigned boosters comes from lab and animal studies.

Waiting for more conclusive data from clinical trials could take too long, said Dr. Kristin Englund, an infectious disease physician at the Cleveland Clinic.

“It would take us beyond this fall season where we are expecting to see increasing numbers of infections,” Englund said.

The FDA had in June said it would not require studies testing the shots in humans for authorization, similar to how annual changes to flu vaccines are cleared.