The number of measles cases exceeded 500 in Texas on Tuesday, according to the state’s health department, which made the update days after a second Texas child died after contracting the highly contagious illness that has been confirmed in at least 20 states.

The Texas measles outbreak that started in January has grown to 481 confirmed cases as of Friday, April 4, with at least 59 new infections this week.

Kennedy Jr. met with the families of two girls who had died from measles in West Texas—and raised doubts about the safety of vaccines. “He said, ‘You don’t know what’s in the vaccine anymore,’” Peter Hildebrand,

Robert F. Kennedy Jr.’s response to the outbreak has drawn criticism from both serious scientists and his most loyal supporters