The protective effect of naturally acquired humoral immunity against human papillomavirus (HPV) infection remains unclear. To investigate the role of infection-induced antibodies on HPV detection in heterosexual partners, we used data from 392 unvaccinated couples (females aged 18-25 years attended up to six visits over 2 years; males aged 17-37 years attended up to two visits 4 months apart) enrolled (2005-2011) in Montreal. Genital and blood samples were HPV DNA genotyped and tested for …