Vashon Island: The place where many parents skip jabs
11 April 2017 Last updated at 00:08 BST
There is alarm from some doctors in the US that President Trump could usher in a new era of scepticism about vaccines, which save millions of lives around the world every year.
An island in Washington state has some of the lowest vaccination rates in the country. Are parents there endangering lives?
Filmed by Bliss Holloway; Edited by Joni Mazer-Field
Produced by Mat Morrison