Goal-oriented browsing on YouTube reduced the likelihood of encountering anti-vaccine videos. Conversely, direct navigation that started from an anti-vaccine video led to more encounters with similar content. In the two seed networks created to resemble direct navigation, pro-vaccine videos, anti-vaccine videos, and videos containing non-vaccine-related health misinformation were all more likely to lead to further anti-vaccine videos. Furthermore, although YouTube has increased the search rankings of pro-vaccine videos to combat misinformation, when viewers are directed to anti-vaccine videos on YouTube from external sites, the algorithm is still likely to recommend additional anti-vaccine content.