A systematic review of psychological factors influencing attitudes and intentions toward, and uptake of, Covid-19 vaccines in adolescents

Vaccination was a key measure to tackle the Covid-19 pandemic, however adolescents were less likely than adults to accept the vaccine. Low vaccine uptake reduces the effectiveness of vaccination campaigns and threatens global public health. Understanding why adolescents are hesitant to accept new vaccines is therefore crucial to support the development of novel vaccine uptake interventions. Prior reviews have included far fewer citations, excluded qualitative data, studies after 2022 and have not mapped adolescent Covid-19 vaccine behaviour onto psychological models. This systematic review investigated psychological factors influencing attitudes and intentions toward and uptake of Covid-19 vaccines in adolescents aged 10 to 19 years globally. It mapped results onto the COM-B framework to inform future interventions. Our search identified 25,354 citations, and included 77 in this review. The quality of studies was mixed, predominantly cross-sectional in design. According to our review, key influences on adolescent Covid-19 vaccine behaviour were: i) Reflective motivation (safety concerns, perceived susceptibility to/severity of Covid-19, perceived vaccine effectiveness, ii) Social opportunity (social norms, autonomy and prosocial attitudes), iii) Psychological capability (attitude and knowledge about vaccines). Our review provides new insights into psychological factors influencing adolescent Covid-19 vaccine behaviour, and maps factors to the COM-B model of behaviour change. To improve vaccine uptake, future vaccine interventions should support adolescents to think critically about the pros and cons of vaccines and consider external influences on their decisions.