Vaccination is key to developing herd immunity against COVID-19; however, the attitude of Nigerians towards being vaccinated stalled at the 70% vaccination target. This study engages Theory of Planned Behaviour to analyse the tone of Nigerian YouTube headlines/titles, and the tone of YouTube users' comments to examine the causes of COVID-19 vaccine hesitancy. YouTube videos uploaded between March 2021 and December 2022 were analysed using a content analytic approach. Results show 53.5% of the videos had a positive tone, while 40.5% were negative, and 6% neutral. Second, findings indicate most of the Nigerian YouTube users' comments were neutral (62.6%), while 32.4%, were negative, and 5% were positive. From the antivaccine themes, analysis shows the people's lack of trust in the government on vaccines (15.7%) and the presence of vaccine conspiracy theories mostly related to expressions of religion and biotechnology (46.08%) were the main causes of COVID-19 vaccine hesitancy in Nigeria. The study presents implications for theory and recommends ways for governments to develop better vaccination communication strategies.
Keywords: COVID-19 vaccine; content analysis; health communication; theory of planned behaviour.