The U.S. Centers for Disease Control and Prevention panel of vaccine experts will vote on shots for respiratory syncytial virus and influenza at a meeting scheduled for June 25 and 26, according to the agency's website.

Fiona Havers, who oversaw CDC respiratory virus data, told colleagues she no longer had confidence the data would be used objectively to set vaccine policy.

A senior scientist at the U.S. Centers for Disease Control and Prevention has resigned, warning that changes in leadership may weaken the country's vaccine program.