Transcript for How Facebook is fighting anti-vaxxing propaganda
That's "Pop news," everybody. Facebook taking often a new fight cracking down on vaccine misinformation spreading online after those recent measles outbreaks. Erielle reshef is back with the details. Hey, erielle. Hey, George. The measles is preventable but so far this year there have been more than 200 cases in 11 states. Mostly in unvaccinated children. The world health organization calling the decision not to vaccinate a global threat. Now Facebook is taking sweeping steps to curb the spread of misinformation about vaccines vowing to fight back. Any time that we see misinformation, hoaxes, inaccurate information about vaccines being shared in a group or a page, we will be taking action. Reporter: The announcement coming as the hot button topic is making headline. My mother is an anti-vax advocate. Reporter: This week Ethan Lindenberger testifying before congress that his mother decided not to vaccinate him based on myths perpetuated online. Facebook now saying it will reduce the ranking of pages that spread falsehoods and reject ads that contain misinformation. If we see people sharing this sort of content on Facebook, immediately we will make sure that that content, those pages, those groups don't appear in what I'll call search type head and we'll remove them from recommendations. Reporter: The issue of childhood vaccination an emotional minefield on social media with parents facing off. When it comes to vaccinations people have a different concern is the fact that their child is playing with a child that's not vaccinated going to cause some kind ofssue or medical issue and that's scary for a lot of parents. Reporter: But within the medical community, clear consensus, the CDC an American academy of period at tricks stressing the benefits of immewny sayings far outweigh any minimal risk. The CDC and prevention has talked about the effectiveness of vaccines Sean really pushing to have vaccinations for not only children but for adults, as well. There's no science, medical data to support that vaccines cause autism. Vaccines are very effective. They save lives. Reporter: Now the world health organization says vaccines work best when 93 to 95% of people have been vaccinated. So doctors urge it's not just a personal choice. It also affects everyone around you. By the way, Cecilia, Facebook is not alone in taking steps to stop the spread of misinformation on social media. In the past month. Pinterest and YouTube have joined the effort.
This transcript has been automatically generated and may not be 100% accurate.