Serologic response to human papillomavirus genotypes following vaccination: findings from the HITCH cohort study

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.