CDC panel endorses Pfizer Covid booster shots for high-risk adults, rejects plan to distribute widely across America

Walensky addressed the committee Thursday before the vote, thanking them for their work and laying out what’s at stake.

“These data are not perfect, yet collectively they form a picture for us, and they are what we have in this moment to make a decision about the next stage in this pandemic,” she said.

Before the vote, some committee members said they worried that widely offering boosters could interfere with efforts to get the shots to the unvaccinated or potentially reduce confidence in the vaccines’ effectiveness. Others were frustrated that only Pfizer recipients would be eligible to get the shots, leaving out millions of Americans who got the Moderna and Johnson Johnson vaccines.

The vote came at the end of a two-day meeting, where CDC advisors listened to several presentations on data to support the wide distribution of booster shots, including one from a Pfizer executive who displayed data that showed a third shot appears to be safe and boost antibody levels in recipients.

During one presentation Thursday, CDC official Dr. Sara Oliver showed observational studies from Israel, where officials began inoculating the nation’s population ahead of many other countries and started offering third shots to their citizens in late July.

The Israel data has been criticized by at least one FDA official as it is based on so-called observational studies that don’t adhere to the same standards as formal clinical trials. 

“We can use the experience from Israel to inform our knowledge of the safety of boosters,” Oliver said, adding the country has only reported one case of a rare heart inflammation condition known as myocarditis out of nearly 3 million third doses administered.

CDC official Dr. Kathleen Dooling said data also suggests a third dose may reduce the risk of severe illness in older adults and people with comorbidities. Potential risks include myocarditis, although this risk is very rare, occurring mostly in males under 30, she said.

“The third dose of Pfizer-BioNTech Covid-19 vaccine appears to have similar reactogenicity as the second dose,” she added.

The topic of who should get boosters and when has been a contentious topic among the scientific community since the Biden administration last month outlined its plan to widely distribute them.

In a paper published days before an FDA advisory meeting last week, a leading group of scientists said available data showed vaccine protection against severe disease persists, even as the effectiveness against mild disease wanes over time. The authors, including two high-ranking FDA officials and multiple scientists from the World Health Organization, contended in the medical journal The Lancet that widely distributing booster shots to the general public is not appropriate at this time.

In outlining plans last month to start distributing boosters as early as this week, Biden administration officials cited three CDC studies that showed the vaccines’ protection against Covid diminished over several months. Senior health officials said at the time they worried protection against severe disease, hospitalization and death “could” diminish in the months ahead, especially among those who are at higher risk or were inoculated during the earlier phases of the vaccination rollout.

– CNBC’s Robert Towey contributed to this report.