HPV vaccine and age of sexual debut of adolescents: A nationwide cross-sectional study

BACKGROUND: Reports from the literature indicate parental concern that sexual education and HPV vaccine may encourage early initiation of sexual activity. In this context, the present study aims to evaluate possible associations between sexual education, adherence to HPV (Human Papillomavirus) vaccination, and the initiation of sexual activity among Brazilian students. METHODS: This study is based on the analysis of data from the 2019 National Survey of School Health, involving 165,838 participants of both sexes, and representative of the Brazilian school population. Data on demographics, sexual education [guidance on sexually transmitted infections (STIs) and pregnancy prevention], HPV vaccine uptake, and age of sexual initiation were collected. Frequency analyses, logistic regression, and the survey-adjusted Wald test were employed. A significance level of p < 0.05 was adopted. RESULTS: Among individuals aged 13 to 15 years who received counseling regarding STIs or Pregnancy Prevention, HPV vaccination was more likely in both males (STI prevention: aOR 1.69, 95% CI 2.03-1.40, p < 0.001; pregnancy prevention: aOR 1.22, 95% CI 1.45-1.03, p = 0.021) and females (STI prevention: aOR 1.60, 95% CI 1.98-1.30, p < 0.001; pregnancy prevention: aOR 1.44, 95% CI 1.76-1.20, p < 0.001). The survey-adjusted Wald test indicated differences in the mean age of sexual initiation associated with both STI and pregnancy prevention counseling. In both cases, these interventions were associated with a slightly later sexual debut, with mean differences of approximately two months. CONCLUSION: Sexual education in the form of guidance on STIs and pregnancy prevention is associated with higher HPV vaccine uptake, although no causal relationship or chronological relation can be stated on a cross-sectional dataset. STI education, pregnancy prevention counseling, or HPV vaccine uptake showed no clinically relevant association with early or late initiation of sexual activity, as the magnitude of the differences in means is negligible.