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 health secretary is emphasizing the importance of vaccines after previously calling the measles outbreak in Texas “not unusual"

U.S. Health and Human Services Secretary Robert F. Kennedy Jr. said he’s spoken directly with Gov. Greg Abbott about the measles outbreak in Texas, but neither are telling Texas families to get the vaccine that can stop the spread of the highly contagious respiratory illness.