Trump flip-flops on vaccines

President Donald Trump appears to have dropped his opposition to vaccines in the wake of the biggest outbreak of the century in the US.

It's only April, but this year is already the worst on record since measles was eradicated from the US in 2000, meaning outbreaks only happen when someone carrying the virus enters the country.  There have been nearly 700 cases

"They have to get the shots. The vaccinations are so important. This is really going around now. They have to get their shots," Trump told CNN.

The President had previously linked vaccines to autism.

"Massive combined inoculations to small children is the cause for big increase in autism," he tweeted in 2012, following that up in 2014 with: "Healthy young child goes to doctor, gets pumped with massive shot of many vaccines, doesn't feel good and changes - AUTISM. Many such cases!"

During a Republican primary debate in 2015 he said it was the size of the vaccines - "meant for a horse" - that caused the problems.

Trump also reportedly held meetings with anti-vaccine activists during his 2016 election campaign.

The belief vaccines cause autism was started by a fraudulent research paper published in The Lancet in the late 1990s. The researcher behind it was later stripped of his credentials, and no reputable study has found any link whatsoever.

Earlier this year the World Health Organization named anti-vaccine activism one of the top 10 threats to global health.