Factors influencing vaccine hesitancy among United Kingdom adolescents in a senior high school environment and actions to address it.

We explored adolescent viewpoints on vaccines and hesitancy using an anonymized, validated, self-completed electronic questionnaire amongst state-school Year 12-13 adolescents in London, UK. As the response rate was low (Cohort 1;  = 112/486, 23.0%), we repeated the survey with incoming students (cohort 2,  = 256/275; 93%). A focus group ( = 31) evaluated international HPV campaign posters. Cohort 1 participants were 82.1% female, 13.4% male, and ethnically diverse (32.1% Asian/Asian British, 29.5% Black/Black British, 25.9% White, 7.1% Mixed); Cohort 2 were 80% female, 18% male, with participants identifying as 38% Black/Black British, 34% Asian/Asian British, 15% White, 12% Mixed/Others. Across both cohorts, participants believed childhood vaccinations were safe (Cohort 1 = 95.8%, Cohort 2 = 91%). COVID-19 vaccination uptake was higher in Cohort 1 than 2 (76.8% vs 67%), with fewer participants believing it was adequately tested (56.3% vs 47%). Support for mandatory COVID-19 vaccination for healthcare workers (HCW) was high (Cohort 1:77.8-79% "all" vs "patient-facing HCWs;" Cohort 2 = 62-64%). Similar patterns were observed for mandatory influenza vaccination (Cohort 1: 62.5-66.7%; Cohort 2: 62-63%). Vaccination decisions in Cohort 2 were primarily influenced by parents (96%), healthcare providers (48%), and school friends (36%) (Cohort 1 = 30.2%, 19.6%, and 12%, respectively). Recommendations by doctors, experts and parents (but not politicians) and school-based vaccine availability boosted vaccine confidence. Social media had minimal impact. Most participants received HPV vaccine (Cohort 1 = 83.1%, Cohort 2 = 77.2%). International HPV posters received strong but mixed support; direct design input from the target group is needed to ensure the success of visual vaccine promotions.