Fauci said there will likely be a need for an 'additional boost' of COVID-19 vaccine 'sooner or later'

• Dr. Anthony Fauci said Sunday that a COVID-19 booster shot will likely be needed at some point in the future.
• Fauci said he supported a third vaccine shot for people with weakened immune systems as soon as possible.
• But all Americans, and especially the elderly, will likely need to get another jab in the future, he said.

Dr. Anthony Fauci, the longtime director of the US National Institute of Allergy and Infectious Diseases, said Sunday that it was likely there would be a need for a COVID-19 booster shot sometime in the future.

Fauci made the comments during an appearance Sunday on NBC's "Meet the Press." He said he supported individuals with immunocompromising conditions - like individuals who receive chemotherapy treatments and those who have had organ transplants and take immunosuppressive drugs - should receive a third dose of the vaccine "as soon as possible."

The US Food and Drug Administration is expected to review new data from the Centers for Disease Control and Prevention that supports using additional vaccine doses for individuals with weakened immune systems, The Washington Post reported.

According to the report, FDA officials could revise the emergency use authorizations for the coronavirus vaccines to include extra doses for immunocompromised people.

But others, especially the elderly, will likely need a booster shot in the future as vaccines typically become less effective over time, Fauci told NBC's Chuck Todd on Sunday.

"There's no doubt that over time you're going to have an attenuation of protection," said Fauci, a senior adviser to President Joe Biden. Fauci said data from Pfizer showed its vaccine went from an efficacy rate of the 90s to around the mid-80s a few months post-vaccination.

"The recent data from Moderna shows that it isn't really going down, but everyone assumes, and I think correctly, that sooner or later you're going to see an attenuation to the point where you're going to have to give a boost to people," he said.

The booster shot will likely be prioritized for elderly people before becoming more widely available, Fauci added.

His comments come as the US reached a milestone Saturday with over 50% of the population fully vaccinated against COVID-19 amid a surge of the more contagious Delta variant across the US.

Fauci repeated Sunday that the vaccines were effective in preventing serious illness and death even in the case of breakthrough infections, and said the ongoing surge of the disease is being fueled by unvaccinated Americans.

"It's a pandemic and an outbreak among the unvaccinated," he said. "If you are vaccinated you are very well protected against getting infected."