CDC Won't Change 'Fully Vaccinated' Definition, Urges Staying Up to Date on Booster Shots

The Centers for Disease Control and Prevention (CDC) announced Wednesday it would not change its definition of "fully vaccinated" against COVID-19 to require a booster shot, but the group still encouraged the public to get their third doses.

This will allow the "fully vaccinated" designation to keep applying to those who have received two doses of the Moderna or Pfizer vaccine or one dose of the Johnson & Johnson vaccine.

Several health experts have been pushing for the definition to include the booster due to the vaccines' effects diminishing over time. Some worry that keeping the definition as it is might discourage people from getting booster shots—especially those who had to be convinced just to get the initial vaccination.

However, CDC Director Dr. Rochelle Walensky said the definition "is not changing," but she added, "We are now recommending that individuals stay up to date with additional doses that they are eligible for."

The lack of a definition change also means that people will not need a booster in order to be in compliance with federal vaccination mandates.

A CDC spokeswoman said that the organization will use the phrase "up to date" when referring to vaccinations.

"CDC recommends that individuals stay 'up to date' by receiving any additional doses they are eligible for, according to CDC's recommendations, to ensure they have optimal protection against COVID-19," she said.

Anthony Fauci, Rochelle Walensky
The CDC announced it would not change its definition of "fully vaccinated" against COVID-19 to require a booster. Above, Dr. Anthony Fauci, chief medical adviser to the president, and Dr. Rochelle Walensky, director of the CDC, arrive for a video call in the South Court Auditorium at the Eisenhower Executive Office Building on December 27 in Washington, D.C. Photo by Anna Moneymaker/Getty Images

Also on Wednesday, the CDC posted updated information online for Americans to more easily determine their eligibility for booster doses so as to remain up to date with their COVID-19 shots.

Jeff Zients, the White House COVID-19 coordinator, said the administration was not considering an adjustment to require booster shots for international travel or for workers covered by a slew of vaccination mandates instituted by President Joe Biden to press tens of millions of Americans to get the shots.

"That has not changed, and we do not have any plans to change that," he told reporters during a White House briefing.

More than 71 million Americans have received a booster dose, according to CDC data.

"I do think it's really important to recognize the vast majority of hospitalizations and deaths are among the unvaccinated Americans," Zients said. "Completing the primary vaccination series is clearly a critical step to prevent severe outcomes, with boosters, as Dr. Walensky said, giving the highest level of protection."

He added, "As to the definition, someone is considered fully vaccinated if they've received their primary series of vaccine."

Shortly before the White House briefing, the CDC revised an agency web site that had been entitled "When You've Been Fully Vaccinated" that defined the term and talked about what people could do after they achieved that level of protection.

It was retitled "Stay Up to Date with Vaccines," and used the term "fully vaccinated" sparingly to describe the primary series. Much of the site discussed additional and booster doses.

Dr. Anthony Fauci, Biden's top science adviser on the COVID-19 response, said Tuesday that the administration was shifting how it talked about vaccinations and getting booster doses.

"We're using the terminology now 'keeping your vaccinations up to date,' rather than what 'fully vaccinated' means," he said during a National Institutes of Health lecture.

The Associated Press contributed to this report.