Vaccination reduces HPV prevalence by almost half among young people in Brazil

HPV vaccination has reduced the presence of the main types of the virus by almost half among young people in Brazil, according to the largest study on the vaccine's efficacy ever conducted in Latin America. The research, which compared data from different periods, demonstrates the positive impact of immunization on national public health.

The Pop-Brasil study, developed by Hospital Moinhos de Vento in partnership with the Ministry of Health, analyzed the prevalence of the virus in young people aged 16 to 25. The data showed that the infection rate for the four types of HPV covered by the vaccine dropped from 14.98% (collected between 2016 and 2017) to 7.95% (collected between 2020 and 2023).

The investigation highlighted the phenomenon known as the 'herd effect', where the immunization of a portion of the population indirectly protects those who have not been vaccinated. Among unvaccinated women, the prevalence of the subtypes combated by the vaccine dropped from 15.6% to 10.5% during the analysis period.

Among men, the reduction was notable among the vaccinated, with prevalence dropping from 13.8% to 4.6%. However, there was no significant change among male participants who did not receive the dose, which epidemiologist physician Eliana Wendland attributes to low vaccine coverage in this group, which shows only 31.1% immunization.

The research also validated the efficacy of the single-dose schedule adopted by the Unified Health System (SUS). The results showed no difference in the prevalence of the virus among individuals who received one, two, or three doses of the vaccine.

HPV is the main causative agent of cervical cancer, in addition to being related to tumors in the penis, anus, and throat. Currently, the target audience for vaccination in SUS includes children and adolescents aged 9 to 14, as well as vulnerable adult groups, such as the immunosuppressed and victims of sexual violence.