title: Different population-level vaccination effectiveness for HPV types 16, 18, 6 and 11.
authors.affiliation: Département de Médecine Sociale et Préventive, Université Laval, Québec, Canada. marc.brisson@uresp.ulaval.ca
authors.forename: Marc
authors.initials: M
authors.lastname: Brisson
authors.forename: Nicolas
authors.initials: N
authors.lastname: Van de Velde
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Boily