Effect of vaccination against oral HPV-16 infection in high school students in the city of Cali, Colombia

INTRODUCTION: In recent years, an association between HPV-16 and oropharyngeal cancers has been reported. Therefore, it is necessary to evaluate whether vaccination decreases the exposure of HPV-16 in the oral cavity. OBJECTIVE: To evaluate the effect of vaccination on oral HPV-16 infection in high school students in the city of Cali, Colombia. METHODS: In this cross-sectional study, HPV-16 DNA was detected in samples from the oral cavity and throat of 1,784 high school students of both genders, aged 14–17 years old, in 21 schools in the city of Cali, Colombia. The number in vaccinated girls were 944 vs., 95 unvaccinated girls and 745 unvaccinated boys. RESULTS: The HPV exposure percentages were: 0.7% in vaccinated girls, 3.2% in unvaccinated girls and 2.3% in unvaccinated boys. The odds ratio (OR) of detection of HPV-16 in vaccinated versus unvaccinated students was 0.28 (95% CI: 0.07–0.88), representing a 72% reduction in HPV-16 detection in students immunized with two doses. The odds of detection of HPV-16 in unvaccinated male students were 3.6 times those of vaccinated girls (OR = 3.6, 95% CI: 1.21–12.81) and increased to almost eight-fold in boys who had initiated sexual activity (OR = 7.74, 95% CI: 1.53–75.09). CONCLUSIONS: HPV vaccination was associated with the reduction of HPV-16 exposure percentages in the oral and oropharyngeal cavity.