"We're committed to protecting the health of the public conversation on Twitter — ensuring individuals can find information from authoritative sources is a key part of that mission," the company said. Twitter will also block auto-suggestions for queries that might lead to anti-vax commentary and information.

For now, the new search prompt can be found on iOS, Android and mobile.twitter.com in the US, Canada, the UK, Brazil and Korea. It's also available on Twitter.com in Japan, Indonesia, Singapore and in Spanish-speaking Latin American countries. Twitter takes similar action when people search for terms associated with suicide or self-harm, directing them to Lifeline. The company says it plans to expand the feature to other important public health issues in the coming months.