COVID-19 booster for immunocompromised to be approved 'imminently,' Fauci says

U.S. approval of an additional COVID-19 booster vaccine for people with weakened immune systems is expected to come "imminently," Dr. Anthony Fauci said Thursday — adding that it’s likely everyone will need one eventually.

Fauci, the nation’s top infectious disease expert, said a booster vaccine will be recommended for people who are immunocompromised during an interview with NBC’s "Today." Authorization for an additional shot would come from the U.S. Food and Drug Administration. 

Fauci added that people other than the immunocompromised do not need booster shots "at this moment," as echoed by the U.S. Centers for Disease Control and Prevention. But "inevitably," most will likely need a booster dose in the future, he said.

"No vaccine, at least not within this category, is going to have an indefinite amount of protection," Fauci told "Today." Data is currently being collected for other vaccinated groups, such as the elderly, to determine if or when their protection falls below a critical level.

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FILE - A sign promotes COVID-19 vaccines at Lake Charles Memorial Hospital on Aug. 10, 2021, in Lake Charles, Louisiana. (Photo by Mario Tama/Getty Images)

The anticipated FDA approval of a third shot of the Moderna and Pfizer-BioNTech vaccines comes as a surge in new daily cases fueled by the highly transmissible delta variant makes its way through the country. The U.S. is averaging more than 116,000 new COVID-19 infections a day along with about 50,000 hospitalizations — levels not experienced since the winter surge. 

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The U.S. Centers for Disease Control and Prevention has identified immunocompromised people as being at higher risk for getting severely ill from COVID-19, more likely leading to hospitalization or death. 

Nearly 3% of the U.S. adult population is immunocompromised, according to the CDC. Among them are people with HIV or AIDS, transplant recipients, some cancer patients and people with autoimmune disorders such as rheumatoid arthritis, inflammatory bowel disease and lupus, the CDC explains on its website.

Emerging evidence has indicated people with weakened immune systems could benefit from a booster dose of vaccine in order to bump up their antibody response against the virus. Most recently, a study published Wednesday in the New England Journal of Medicine reported that a third dose of Moderna's COVID-19 vaccine substantially improved protection for organ transplant recipients.

U.S. health officials have long said that people one day might need a booster, as they do for many other vaccines. That’s why studies are underway to test different approaches: simple third doses, mix-and-match tests using a different brand for a third dose, or experimental boosters tweaked to better match different variants.

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Meanwhile, Israel started giving boosters to older adults. Several other countries, including Germany, Russia and the U.K., have approved them for some people. The head of the World Health Organization recently urged wealthier nations to stop administering boosters to ensure vaccine doses are available to other countries still struggling to administer the first shots. 

COVID-19 shots weren’t studied in large numbers of people with weak immune systems. But limited data and experience with flu and pneumonia vaccines suggest they won’t work as well as they do in others. But experts say the shots should still offer some protection. 

It’s why vaccinations are still recommended for people with immune systems weakened by disease or certain medications. It’s also important that family, friends and caregivers get vaccinated, which will make it far less likely that they pass on the virus.

"It’s prudent to use all the precautions you were using before you were vaccinated," said Dr. Ajit Limaye, a transplant expert at the University of Washington Medicine in Seattle.

Although most cancer patients should get vaccinated as soon as they can, people getting stem cell transplants or CAR T-cell therapy should wait at least three months after treatment to get vaccinated, according to guidance from the National Comprehensive Cancer Network. That delay will make sure the vaccines work as well as they can.

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The Associated Press contributed to this report.