Vaccination of Young Women Decreases Human Papillomavirus Transmission in Heterosexual Couples: Findings from the HITCH Cohort Study
Menée au Canada sur la période 2005-2013 par questionnaire auprès de 497 femmes (âge : 18-24 ans) et à l'aide de prélèvements génitaux, cette étude analyse l'effet de la vaccination anti-papillomavirus humain sur la transmission du HPV au sein des couples hétérosexuels
Background : Vaccination against human papillomaviruses (HPV) prevents HPV infections and, consequently, cervical lesions. However, the effect of vaccination on HPV transmission within couples is unknown. Methods : We used data from HITCH, a prospective cohort study of heterosexual couples (women ages 18–24 years) in Montreal, 2005 to 2013. Vaccination history was self-reported. Genital samples were tested for HPV DNA by PCR (linear array). Type-specific viral loads were quantified using real-time PCR. OR and HR were estimated using multilevel mixed-effects logistic regression and a parametric model for interval- censored survival-time data, respectively. Differences in viral loads were evaluated using the Friedman ANOVA test. Results : Among 497 couples, 12, 16, and 35 women received 1, 2, or 3 vaccination doses at baseline, respectively. Median age at vaccination was 18 years. Most women (92.1%) had their first coitus before vaccination. At baseline, partner concordance of persistent HPV6/11/16/18 infections was lower in vaccinated than unvaccinated women [adjusted OR = 0.10; 95% confidence interval (CI), 0.01–0.65] but not for non α7/α9/α10-HPV types (adjusted OR = 1.00; 95% CI, 0.44–2.29). Incidence of persistent α7/α9/α10 HPV types in women was inversely associated with vaccination status at baseline (adjusted HR = 0.12; 95% CI, 0.03–0.47). Likewise, male partners of vaccinated women had a lower incidence of α7/α9/α10 HPV infections (adjusted OR = 0.22; 95% CI, 0.05–0.95). Vaccinated women with HPV 6/11/16/18 infections had lower viral loads (P = 0.001) relative to unvaccinated women. Conclusions : Vaccination of sexually active women significantly reduced transmission of α7/α9/α10 HPV types in heterosexual couples. Impact : These results underscore and quantify the positive effect of HPV vaccination on HPV transmission within heterosexual couples.