Other companies like Facebook, YouTube and Twitter have also been infiltrated with misinformation about vaccines. But only Pinterest, as first reported by The Wall Street Journal, has chosen to banish results associated with certain vaccine-related searches, regardless of whether the results might have been reputable.

“Right now, blocking results in search is a temporary solution to prevent people from encountering harmful misinformation,” Jamie Favazza, a spokeswoman, said. The company said it was working with experts to develop a more tailored long-term approach…

An analysis by The Daily Beast of seven Facebook pages that promote anti-vaccine posts found that the pages had bought a combined 147 Facebook ads that had been viewed millions of times. Most of them targeted women over the age of 25, it reported.