Characteristics of YouTube videos about the meningococcal B vaccine (4CMenB)

Information in Spanish on YouTube about Covid-19 vaccines

Our objective was to analyze the sources, characteristics, tone, and content of the most viewed YouTube videos in Spanish about Covid-19 vaccines. In February 2021, a search was carried out on YouTube using the terms "Vacuna Covid," "Vacuna coronavirus," and "Vacuna Covid19." Associations between tone, source, and others variables (e.g. number of views or dislikes) were studied with a Mann-Whitney U-test and a chi-square test. A total of 118 videos were analyzed; 63.6% were originated from Mexico and the USA; media created 57.6% of the videos. Positive tone was observed in 53.4%. The most discussed topics were target groups for vaccination (38.9%) and safety (43.2%). The 68 videos produced by media accumulated 31,565,295 views (55.0% of views), and the 19 videos created by health professionals obtained 10,742,825 views (18.7% of views). A significantly smaller number of likes was obtained in videos of media compared to those created by health professionals (p = .004). Videos made by health professionals, compared to those of media, showed a greater positive tone (OR = 3.09). Hoaxes/conspiracy theories were identified in 1.7% of the videos. Monitoring that the information on YouTube about Covid-19 vaccines is reliable should be a central part of Covid-19 vaccination campaigns.

YouTube as a Source of Influenza Vaccine Information in Spanish

Our objective was to analyze the information in Spanish on YouTube about the influenza vaccine. In August 2020, a search was conducted on YouTube using the terms “Vacuna gripe”, “Vacuna influenza”, and “Vacuna gripa”. Associations between the type of authorship, country of publication, and other variables (such as tone, hoaxes, and vaccination recommendations) were studied via univariate analysis. A total of 100 videos were evaluated; 57.0% were created in Mexico (24.0%), Argentina (17.0%), and Spain (16.0%), and 74.0% were produced by mass media or health professionals. Positive messages were detected in 65.0%. The main topics were the benefits of the vaccine (59.0%) and adverse effects (39.0%). Hoaxes were detected in 19 videos. User-generated content, compared to that of health professionals, showed a higher probability of hoaxes (odds ratio (OR) = 15.56), a lower positive tone (OR = 0.04), and less evidence of recommendations to vaccinate pregnant individuals (OR = 0.09) and people aged 60/65 or older. Videos published in Spain, in comparison with those from Hispanic America, presented significant differences in the positive tone of their messages (OR = 0.19) and in the evidence of the benefits of vaccination (OR = 0.32). A higher probability of hoaxes was detected in videos from Spain and the USA. Information in Spanish about the influenza vaccine on YouTube is usually not very complete. Spanish health professionals are urged to produce pro-vaccination videos that counteract hoaxes, and users in Hispanic America should be advised to consult videos produced in Hispanic American countries by health professionals to obtain reliable information.