Vaccinating girls and boys against HPV encourages them to have more sexual partners.
This concern, prominent in the early 2000s, was based on moral panic rather than evidence. Multiple large studies (including cohort studies in the US, UK, and Australia involving hundreds of thousands of adolescents) found zero difference in sexual behaviour, age of first intercourse, or number of partners between vaccinated and unvaccinated youth. A 2021 longitudinal study in JAMA tracked nearly 2,000 adolescents through vaccination and early adulthood and found no behavioural differences attributable to HPV vaccination. The vaccine targets Human Papillomavirus, which causes cervical cancer (99% of cases involve HPV), genital warts, and multiple other cancers. A 2021 Finnish study showed that HPV vaccination reduced cervical cancer incidence by 89% compared to unvaccinated cohorts, with cervical cancer rates dropping dramatically in countries with high vaccination coverage. The 'moral licensing' concern, that prevention enables risky behaviour, has no empirical support in decades of behavioural research. By contrast, countries that delayed or rejected HPV vaccines due to these concerns experienced preventable cancer deaths, while countries that vaccinated broadly have seen dramatically improved cancer outcomes.