Kennedy Jr. became the country's top health official, the Centers for Disease Control and Prevention has already pulled back some of its efforts to protect Americans with safe, life-saving vaccines. The agency has indefinitely postponed a public meeting of its vaccine advisory committee and killed a campaign promoting seasonal flu shots.

Health and Human Services officials said the postponement was to accommodate public comment ahead of the meeting but experts decried the delay.

HHS Secretary Robert F. Kennedy Jr. appears to be planning major changes to the way his department oversees vaccines, media outlets are reporting.