KEY POINTS
  • CDC Director Dr. Rochelle Walensky said Thursday that Americans may not need yearly Covid-19 booster shots.
  • Walensky suggested a third shot may sufficiently strengthen the long-term protection of Pfizer's or Moderna's vaccines.
Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention (CDC), and top infectious disease expert Dr. Anthony Fauci, testify before the Senate Health, Education, Labor, and Pensions Committee on Capitol hill in Washington, D.C., July 20, 2021.

CDC Director Dr. Rochelle Walensky said Thursday that Americans may not need yearly Covid-19 booster shots, suggesting that a third shot may sufficiently strengthen the long-term protection of Pfizer's or Moderna's vaccines.

Walensky's remarks come a day after she and other top U.S. health officials said they plan to start offering boosters to all eligible Americans eight months after their second vaccine shots. The effectiveness of mRNA vaccines lessens over time, particularly for anyone at high risk for dangerous coronavirus complications or for those who were immunized early in the vaccine rollout, Walensky and several of the country's top medical officials said in a statement Wednesday.