Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, speaks during a Senate Health, Education, Labor, and Pensions Committee hearing at the Dirksen Senate Office Building in Washington, D.C., U.S., July 20, 2021.
Stefani Reynolds | Reutesr
White House chief medical advisor Dr. Anthony Fauci said Thursday he would not be surprised if the recommended full regimen for the Pfizer and Moderna Covid-19 vaccines in the U.S. becomes three doses, instead of two.
Giving people an additional dose, or perhaps a final dose, several months after they’ve received their initial vaccination helps the immune system mature, said Fauci, also the director of the National Institute of Allergy and Infectious Diseases.
“I must say from my own experience as an immunologist, I would not at all be surprised that the adequate full regimen for vaccination will likely be three doses,” Fauci told reporters during a White House Covid briefing.
The infectious disease expert’s comments come as the Biden administration prepares to begin widely distributing Covid booster shots the week of Sept. 20.
The plan, outlined by senior health officials last month, calls for a third dose eight months after people get their second shot of either the Pfizer or Moderna vaccines.
Federal health officials, citing three new studies released by the Centers for Disease Control and Prevention, said vaccine protection against Covid infection diminished several months after people received their second dose.
Health experts say it is not uncommon for vaccines to require more than two doses. Vaccinations for hepatitis B and HPV, for example, require third doses, with several months between the second and third shot.
While Americans may eventually need to get a third shot, some health experts have urged officials not to call them “boosters.” That’s because, like other vaccines, Americans may not need more boosters at a later time.
Fauci said Thursday he would leave it up to the Food and Drug Administration and other regulators to make a determination on the full regimen, but added it is reasonable to believe three doses would provide a more durable immune response.
“If it is durable, then you’re going to have very likely a three-dose regimen being the routine regimen,” he said.