Dec. 10, 2021 -- White House Chief Medical Advisor Anthony Fauci, MD, says it’s "a matter of when, not if," the definition of “fully-vaccinated” is changed to include a third shot.
"I don't think anybody would argue that optimal protection is going to be with a third shot. It's a technical, almost semantic definition, and it is the definition for requirements," Fauci said Wednesday on CNN.
"My own personal opinion is that it is going to be a matter of when, not if," he said.
Federal health authorities already recommend people get a third, or booster, COVID shot. However, by the CDC’s official definition, a person is fully vaccinated two weeks after receiving a second dose of the Pfizer/BioNTech or Moderna vaccines or two weeks after one dose of the Johnson & Johnson vaccine.
The arrival of the highly transmissible Omicron variant – and before that, the Delta variant – has led many health officials to say extra doses may not be enough for full protection.
Studies released this week showed that the standard two doses of the Pfizer/BioNTech vaccine appear to be much less effective against the Omicron variant than a booster dose.
"We should think of the COVID-19 vaccine as a three-dose vaccine," Peter Hotez, MD, dean for the National School of Tropical Medicine at Baylor Medical, told CNN.
Biden administration vaccine mandates – now on hold while they work their way through the courts – have applied the CDC’s current definition of what fully vaccinated means -- two doses of Pfizer or Moderna or one dose of Johnson & Johnson. Mandates by businesses, colleges, and other organizations have used the same standard.
Changing the definition and requiring a third dose could cause enforcement problems, said William Schaffner, MD, chair of the department of preventive medicine at Vanderbilt University School of Medicine and liaison to the CDC's Advisory Committee on Immunization Practices.
"Changing the requirements of what fully vaccinated means, I think, has all kinds of downstream effects for all kinds of institutions in the country," Schaffner said on CNN. "I don't think we're quite there yet."
Pfizer officials said Wednesday that the Omicron variant could make it more likely that people will need a fourth dose of vaccine earlier than expected.