Instagram is cracking down on anti-vaccine conspiracy theories. The company announced Thursday that it will block hashtags that surface false information about vaccines.

With the change, which is beginning to take effect now, Instagram will prevent the hashtags it's identified from appearing in search results and hashtag pages. Instagram has previously done this to address hashtags associated with self harm or selling drugs.

The change comes as Facebook faces public pressure to do more to prevent anti-vaccination conspiracy theories and propaganda from spreading.

Importantly, the company isn't blocking anti-vaccination sentiment entirely. Instagram will make a distinction between specific, "scientifically false" information ("vaccines cause autism"), which will be blocked, and statements that are more vague ("vaccines make me feel bad").

To make this distinction, Instagram is taking a similar approach to how Facebook addressed anti-vaccination conspiracy theories on its platform. The company is relying on information from the World Health Organization and other organizations that have debunked "scientifically false" information about vaccines in the past.

Critics will likely argue that this doesn't go far enough. The pages that were created to sow fear in parents about vaccinations will still be around, and their followers will still be able to see their posts.

But by removing the worst offenders from search results, Instagram is at least tackling one of the most obvious problems: it's unbelievably easy to find blatant anti-vaccine conspiracy theories and propaganda on Instagram.

In fact, at the very moment that Instagram's policy team was briefing reporters on the changes, a search in the Instagram app showed that nearly all the top results for "vaccine" were pages spreading conspiracy theories and false information.

In order to address this, the company is also planning an in-app popup that will appear when people search for vaccine-related content. It's not yet clear exactly what this will look like, but Instagram says the goal is to direct people to accurate information on the topic from reputable sources.