After seeing a number of what it calls false claims about vaccines, YouTube is vowing to crack down on medical misinformation. The online video platform says it will be extra-vigilant about checking all uploaded videos for inaccurate information, and those that contain falsehoods will be removed immediately. "Specifically, content that falsely alleges that approved vaccines are dangerous and cause chronic health effects, claims that vaccines do not reduce transmission or contraction of disease or contains misinformation … will be removed," company officials wrote in a blog post. The new policy went into effect on Wednesday.