YouTube and Informed Decision Making about COVID-19 Vaccination: A Successive Sampling Study.

BACKGROUND Social media such as YouTube are where many people seek and share health content that may influence their decision making about COVID-19 vaccination. OBJECTIVE The purpose of this study was to improve understanding about the sources and content of widely viewed YouTube videos on COVID-19 vaccination. METHODS Using the keywords "coronavirus vaccination," we searched YouTube, sorted by view count, and selected two successive samples (with replacement), of the 100 most widely viewed videos in July and December 2020, respectively. Content related to COVID-19 vaccines were coded two observers and inter-rater reliability was demonstrated. RESULTS The videos observed in this study were viewed over 55 million times. The number of videos that addressed fear increased from 6 to 20 and cumulative views increased from 2.6 % (1,449,915) to 16.6% (9,553,368). There was also a large increase in the number of videos and cumulative views with respect to concerns about vaccine effectiveness, increasing from 6 videos with ~6 million views to 25 videos with over 12 million views. The number of videos and total cumulative views covering adverse reactions almost tripled from 11 videos with ~6.5 million (11.7% of cumulative views) to 31 videos with almost 15.7 million views (27.2% of cumulative views). CONCLUSIONS Our data show the potentially inaccurate and negative influence social media can have on population-wide vaccine uptake and should be urgently addressed by agencies of the U.S. Public Health Service as well as its global counterparts. CLINICALTRIAL