Youtube was kind enough to put a link directly below the video to Wikipedia for the MMR vaccine.

Drop down box: why am i seeing this.

Information panel providing topical context
Note: This feature is currently available only in the United States and South Korea.

Users may see information from third parties, including Encyclopedia Britannica and Wikipedia, alongside videos on a small number of well-established historical and scientific topics that have often been subject to misinformation online, like the moon landing.

An information panel providing topical context may appear in search results or on the Watch page of videos. It will include basic, independent third party information about a given topic, and will link to the third party partner’s website to allow viewers to learn more about the topic.

This information panel will appear alongside videos related to the topic, regardless of the opinions or perspectives expressed in the videos.
Note: This information panel isn’t used in any decisions regarding monetization. For advertiser-friendly content guidelines, learn more here.


Full video live stream.