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Vaccine vials and needle

COVID-19 vaccine boosters authorized for all adults

November 20, 2021

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Federal health officials have expanded eligibility for a COVID-19 vaccine booster dose to include all adults ages 18 and older.

Experts say the move on Friday could clear up confusion and provide extra protection as the holidays and winter season approach.

“Booster shots have demonstrated the ability to safely increase people’s protection against infection and severe outcomes and are an important public health tool to strengthen our defenses against the virus as we enter the winter holidays,” Centers for Disease Control and Prevention (CDC) Director Rochelle P. Walensky, M.D., M.P.H., said in a statement. “Based on the compelling evidence, all adults over 18 should now have equitable access to a COVID-19 booster dose.”

Her statement came Friday morning as the Food and Drug Administration granted emergency use authorization to boosters for everyone 18 and older who had received one of the two mRNA vaccines as their primary series. Hours later, the CDC’s Advisory Committee on Immunization Practices (ACIP) voted 11-0 in favor and the CDC director gave final approval.

About 195 million people in the U.S. are fully vaccinated, according to the CDC. However, there has been some evidence protection is waning, and cases are starting to rise again in some states.

The approval means all adults who received the Pfizer-BioNTech or Moderna vaccines are eligible for a booster with any authorized vaccine at least six months after their primary series. The Pfizer-BioNTech booster is the same 30-microgram dose as the primary series doses, while the Moderna booster is 50 micrograms, half the primary series doses.

“As a clinician deep in the clinical trenches, I am really glad we have clarity and streamlining of the recommendations so that all Americans can understand the vaccines that are recommended for them at this time,” said ACIP member Camille N. Kotton, M.D., FIDSA, FAST, clinical director, transplant and immunocompromised host infectious diseases, at Massachusetts General Hospital.

The previous booster recommendations caused some confusion as they were based on a combination of age and underlying medical conditions or occupational exposures.

While about 31 million have received a booster dose, a survey found 40% of fully vaccinated adults aren’t sure if they are eligible. Nirav Shah, M.D., J.D., president of the Association of State and Territorial Health Officials, urged expansion and simplification of the guidelines during Friday’s ACIP meeting.

“The current guidelines, though well-intentioned and thoughtful, create an obstacle to uptake of boosters,” Dr. Shah said. “In pursuit of precision, they create confusion. … Individuals who right now are absolutely eligible for boosters are not able to parse the guidelines and come to that conclusion on their own.”

ACIP members reviewed data on safety and efficacy of the boosters. A Pfizer-BioNTech trial found relative efficacy of a booster in preventing symptomatic infection to be about 95%. Moderna did not present booster efficacy data but has shown the geometric mean titer ratio met non-inferiority criteria.

Data from the v-safe system in which people report side effects from vaccination showed local and systemic reactions after boosters were less frequent than after dose two. Moderna boosters appear to be more reactogenic than the Pfizer-BioNTech booster.

Officials have been closely watching reports of myocarditis after vaccination, which have been rare, and did not present new concerns about boosters. A study of myocarditis rates after receipt of the Pfizer-BioNTech vaccine in Israel found the risk to be lower after a booster than after dose two.

ACIP members on Friday expanded their recommendations as to who should get a booster vs. who may get one. Among those who initially were vaccinated with Pfizer-BioNTech or Moderna, everyone ages 50 and older and people 18 and older who live in long-term care facilities should get a booster. All other adults may get a booster.

“It’s a stronger recommendation, and I want to make sure we provide as much protection as we can and I think there’s some benefits for the 50- to 64-year-olds broadly,” said ACIP member Matthew F. Daley, M.D., senior investigator at the Institute for Health Research at Kaiser Permanente Colorado.

Friday’s actions did not impact people who initially got a Johnson & Johnson vaccine. All adult recipients should get a booster with any authorized vaccine at least two months after their original dose.



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