President-elect Donald Trump’s announcement Thursday that he had chosen anti-vaccine activist Robert F. Kennedy Jr. to lead the Department of Health and Human Services was met with alarm from doctors and public health advocates.

“Concerned,” said Dr. Mandy Cohen , director of the Centers for Disease Control and Prevention. “I don’t want to go backwards and see children or adults suffer or lose their lives to remind us that vaccines work.

” “Speechless,” said Dr. Richard Besser , former acting director of the CDC, adding that Kennedy “would imperil the health of people across the country.” “Shocked,” said Dr.

Paul Offit, professor of pediatrics at Children’s Hospital of Philadelphia and co-inventor of the rotavirus vaccine. “It’s like Typhoid Mary being in charge of food safety.” But another group was celebrating Trump’s pick: the anti-vaccine movement Kennedy leads.

On Friday, Mary Holland, CEO of the Kennedy-founded anti-vaccine nonprofit Children’s Health Defense , shared her elation on the group’s online TV morning show. She and Polly Tommey, director of CHD.TV and a longtime anti-vaccine activist, reflected on Kennedy’s power within their campaign.

“Bobby Kennedy was the first prominent citizen, the first prominent American, to really take up our banner and to join us,” Holland said of Trump’s pick. “To parents around the world with vaccine-injured children that either were killed or are very injured, I want to thank you for .