KEY POINTS
  • Covid booster shots provide "optimal care" as the deadly virus continues to mutate and spread.
  • The U.S. government is staying firm for the time being on the definition of fully vaccinated, however, top U.S. infectious disease expert Dr. Anthony Fauci said Sunday.
  • The push for booster shots comes in tandem with the rise in cases of the omicron variant.
Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, speaks during a news conference in the James S. Brady Press Briefing Room at the White House in Washington, D.C., on Wednesday, Dec. 1, 2021.

Covid booster shots are "optimal care" as the deadly virus continues to mutate and spread, but the U.S. government is staying firm for the time being on the definition of fully vaccinated, top U.S. infectious disease expert Dr. Anthony Fauci said Sunday.

Currently, two doses of the Pfizer-BioNTech or the Moderna vaccines or one dose of the Johnson & Johnson vaccine provide full vaccination. Health officials will continue to evaluate whether that definition needs to change, Fauci said on ABC's "This Week With George Stephanopoulos."