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Human papillomavirus (HPV) infection contributes to approximately 5% of the worldwide cancer burden. The three-dose HPV vaccine has demonstrated immunogenicity and efficacy. Humoral responses may be critical for preventing, controlling, and/or eliminating HPV infection. Using data from the HITCH cohort, we analysed humoral immune response to HPV vaccination among women in relation to the phylogenetic relatedness of HPV genotypes. We included 96 women aged 18–24 years attending college or university in Montreal, Canada. Participants provided blood samples at enrolment and five follow-up visits. Antibody response to bacterially expressed L1 and E6 glutathione S‐transferase fusion proteins of multiple Alphapapillomavirus types, and to virus-like particles (VLP-L1) of HPV16 and HPV18 were measured using multiplex serology. We assessed correlations between antibody seroreactivities using Pearson correlations (r). At enrolment, 87.7% of participants were unvaccinated, 2.4% had received one, 3.2% two, and 6.7% three doses of HPV vaccine. The corresponding L1 seropositivity to any HPV was 41.2%, 83.3%, 100%, and 97.0%. Between-type correlations for L1 seroreactivities increased with the number of vaccine doses, from one to three. Among the latter, the strongest correlations were observed for HPV58–HPV33 (Pearson correlation [r] = 0.96; α9-species); HPV11–HPV6 (r = 0.96; α10-species); HPV45–HPV18 (r = 0.95; α7-species), and HPV68–HPV59 (r = 0.95; α7-species). Correlations between HPV-specific antibody seroreactivities are affected by phylogenetic relatedness, with anti-L1 correlations becoming stronger with the number of vaccine doses received. [ABSTRACT FROM AUTHOR]

Background Real-world evidence of human papillomavirus (HPV) vaccine effectiveness (VE) against longitudinal outcomes is lacking among gay, bisexual, and other men who have sex with men (GBM). We compared 12-month incidence and persistence of anal HPV infection between vaccinated and unvaccinated GBM. Methods We recruited GBM aged 16–30 years in Montreal, Toronto, and Vancouver, Canada, from 2017 to 2019. Participants were followed over a median of 12 months (interquartile range, 12–13 months). Participants self-reported HPV vaccination and self-collected anal specimens for HPV DNA testing. We calculated prevalence ratios (PR) for 12-month cumulative incidence and persistence with ≥1 quadrivalent vaccine type (HPV 6/11/16/18) between vaccinated (≥1 dose at baseline) and unvaccinated participants using a propensity score-weighted, modified Poisson regression. Results Among 248 participants, 109 (44.0%) were vaccinated at baseline, of whom 62.6% received 3 doses. PRs for HPV 6/11/16/18 were 0.56 (95% confidence interval [CI],.24–1.31) for cumulative incidence and 0.53 (95% CI,.25–1.14) for persistence. PRs were 0.23 (95% CI,.05–1.03) and 0.08 (95% CI,.01–.59) for incidence and persistence, respectively, among participants who received their first dose at age ≤23 years and 0.15 (95% CI,.03–.68) and 0.12 (95% CI,.03–.54) among participants who were sexually active for ≤5 years before vaccination. Conclusions Findings support national recommendations for HPV vaccination at younger ages or soon after sexual debut. [ABSTRACT FROM AUTHOR]

Background Humoral immune responses may be critical for preventing, controlling, and/or eliminating human papillomavirus (HPV) infection. We analyzed humoral response to natural HPV infection considering phylogenetic relatedness among unvaccinated women. Methods We included 399 young women attending university/college in Montreal, Canada who were participants of the HITCH cohort. Participants provided blood samples at baseline and 5 follow-up visits. Antibody response to bacterially expressed L1 and E6 glutathione S-transferase (GST) fusion proteins, and virus-like particles (VLP-L1) of Alphapapillomavirus types were measured using multiplex serology. We assessed correlations and associations between HPV types at baseline using Pearson correlation coefficients (r) and univariable linear regressions. Results At baseline, > 40% were seropositive for GST-L1 antibodies of at least 1 HPV type. Strong correlations between GST-L1 were observed for α9 HPV types: 58–52 (r = 0.86), 58–33 (r = 0.75), 33–52 (r = 0.72), and between GST-E6: 52–11 (r = 0.84), 52–18 (r = 0.79), 58–33 (r = 0.78), 35–11 (r = 0.76). HPV16 VLP-L1 moderately explained variability in HPV16 GST-L1 (regression coefficient [b] = 0.38, R 2 = 43.1%), and HPV45 GST-L1 in HPV18 GST-L1 (b = 0.68, R 2 = 42.8%). GST-E6 antibodies accounted for a low to moderate proportion of variability in HPV16 and HPV18 GST-E6 (R 2 = 6.4%–62.2%). Conclusions Associations between naturally induced HPV-specific antibodies depend on phylogenetic relatedness. [ABSTRACT FROM AUTHOR]

Couple-based studies have considered human papillomavirus (HPV) transmission between current heterosexual partners (male↔female). Using data from young women and their sequential male partners, we analysed HPV transmission from upstream sexual partnerships (male 1↔female) to downstream sex partners (→male 2). Among 502 females enrolled in the HPV Infection and Transmission among Couples through Heterosexual activity study (2005–2011, Montréal, Canada), 42 brought one male sex partner at baseline (male 1) and another during follow-up (male 2). Female genital samples, collected at six visits over 24 months, and male genital samples, collected at two visits over 4 months, were tested for 36 HPV types (n = 1512 detectable infections). We calculated observed/expected ratios with 95% CIs for type-specific HPV concordance between males 1 and 2. Using mixed-effects regression, we estimated ORs with 95% CIs for male 2 testing positive for the same HPV type as male 1. Detection of the same HPV type in males 1 and 2 occurred 2.6 (CI 1.9–3.5) times more often than chance (29 instances observed vs. 10.95 instances expected). The OR for male 2 positivity was 4.2 (CI 2.5–7.0). Adjusting for the number of times the linking female tested positive for the same HPV type attenuated the relationship between male 1 and 2 positivity, suggesting mediation. High type-specific HPV concordance between males 1 and 2 confirms HPV's transmissibility in chains of sequential sexual partnerships. HPV positivity in an upstream partnership predicted positivity in a downstream male when the linking female partner was persistently positive. [Display omitted] [ABSTRACT FROM AUTHOR]

The article presents a study which evaluates the role of human papillomavirus (HPV) infected partner and sexual practices in the prevalence of HPV infection. The method of the study includes HPV typing of self-collected vaginal and clinician-collected penis and scrotum swabs from women students in Montreal, Quebec and from their male partners. It shows that 56% of the study population were infected with HPV, wherein 85% HPV prevalence was observed among individuals with infected partners.

The authors estimated plausible ranges of the probability of human papillomavirus (HPV) transmission per coital act among newly forming couples by using stochastic computer simulation. Comparative empirical data were obtained in 1996–2001 from a cohort study of female university students in Montreal, Canada. Female prevalence and frequency of sexual intercourse and condom use were set equal to those in the cohort. Simulations included 240 combinations of male prevalence, the relative risk for protected versus unprotected sex, and per-act transmission probabilities. Those that produced expected HPV incidence within the 95% confidence interval observed in the cohort were selected. The observed 6-month cumulative incidence following acquisition of a new partner was 17.0% (95% confidence interval: 11.4, 23.0). Expected incidences consistent with those from cohort findings occurred in 54/240 simulations. The range of per-act transmission probabilities was 5–100% (median, 40%). Male HPV prevalence was the same as or greater than that for women in all consistent simulations. Varying condom effectiveness did not produce better-fitting data. This simulation suggests that HPV transmissibility is several-fold higher than that for other viral sexually transmitted infections such as human immunodeficiency virus or herpes simplex virus 2. With high transmissibility, any potential protective effect of condoms would disappear over multiple intercourse acts, underlining the need for an effective HPV vaccine. [ABSTRACT FROM AUTHOR]

Starting in 2015/16, most Canadian provinces introduced publicly-funded human papillomavirus (HPV) vaccination programs for gay, bisexual, and other men who have sex with men (GBM) aged ≤ 26 years. We estimated 12-month changes in HPV vaccine coverage among community-recruited GBM from 2017 to 2021 and identified baseline factors associated with vaccine initiation (≥1 dose) or series completion (3 doses) among participants who were unvaccinated or partially vaccinated at baseline. We recruited sexually-active GBM aged ≥ 16 years in Montreal, Toronto, and Vancouver, Canada, from 02/2017 to 08/2019 and followed them over a median of 12 months (interquartile range = 12–13 months). We calculated the proportion who initiated vaccination (≥1 dose) or completed the series (3 doses) by 12-month follow-up. Analyses were stratified by city and age-eligibility for the publicly-funded programs at baseline (≤26 years or > 26 years). We used multivariable logistic regression to identify baseline factors associated with self-reported incident vaccine initiation or series completion. Among 165 unvaccinated participants aged ≤ 26 years at baseline, incident vaccine initiation (≥1 dose) during follow-up was 24.1% in Montreal, 33.3% in Toronto, and 38.9% in Vancouver. Among 1,059 unvaccinated participants aged > 26 years, incident vaccine initiation was 3.4%, 8.9%, and 10.9%, respectively. Higher education and trying to access pre-exposure prophylaxis for HIV were associated with incident vaccination among those aged ≤ 26 years, while younger age, residing in Vancouver (vs. Montreal), being diagnosed with anogenital warts, having both government and private extended medical insurance, and being vaccinated against influenza were associated with incident vaccination among those aged > 26 years. We observed substantial gains in HPV vaccine coverage among young GBM within 5 + years of targeted program implementation, but gaps remain, particularly among older men who are ineligible for publicly-funded programs. Findings suggest the need for expanded public funding or insurance coverage for HPV vaccines. [ABSTRACT FROM AUTHOR]