Prevalence of non-vaccine high-risk HPV cervical infections in vaccinated women: a systematic review and meta-analysis
Human Papillomavirus (HPV) is the most common sexually transmitted lower genital tract infection worldwide and the main etiological factor of cervical cancer (CC). Since 2006, vaccines have been implemented to reduce CC-related morbidity and mortality. This systematic review and meta-analysis aimed to evaluate the prevalence of cervical infections by non-vaccine high-risk HPV (HR-HPV) types in women vaccinated against types 16 and 18. This systematic review and meta-analysis used independent electronic databases - Lilacs, WHO, BDENF, State Department of Health SP, Health Information Locator, IRIS, Coleciona Sistema Único de Saúde, BINACIS, IBECS, CUMED and SciELO, on July 14, 2023. Observational studies that evaluated vaccinated and unvaccinated women against HR-HPV and the prevalence of cervical infection by types of HR-HPV were included. Intervention effects were expressed as prevalence ratios (PR). Forest plots were used to visualize vaccination effects. The study protocol was previously registered in PROSPERO, under code CRD42023440610. Of the 7,051 studies, 31 met the analysis criteria. A total of 59,035 women were eligible for this systematic review. The results showed a high prevalence of non-vaccine HR-HPV types, regardless of vaccination status. For HPV 31/33/45 (PR = 0.60 [0.40-0.91]), HPV31 (PR = 0.47 [0.31-0.72]), and HPV 45 (PR = 0.38 [0.22-0.69]), a positive random effect was found. The prevalence of non-vaccine HR-HPV cervical infection was high in women, regardless of vaccination status. For HPV types 31 and 45 and 31/33/45, the prevalence was lower in vaccinated women, suggesting a cross-protective effect of vaccines for these viral types.