Kennedy's acknowledgement of the value of the measles vaccine comes as the outbreak that began in Texas continues to grow. So far, nearly 150 cases and one death—the first U.S. fatality from the disease in more than 10 years—have been confirmed. It's the largest measles outbreak in the U.S. in decades.

The top spokesperson at the Health and Human Services Department resigned Monday after clashing with Robert F. Kennedy Jr. over his response to the measles. Thomas Corry said he called it quits “effective immediately” in a post on his LinkedIn account just two weeks into his tenure at the agency.

Health and Human Services Secretary Robert F. Kennedy, Jr. is urging people to receive measles vaccinations amid an outbreak after he doubted their efficacy for years. Senior Scholar at the Johns Hopkins University Center for Health Security Dr.