Cross-neutralizing antibodies elicited by the Cervarix human papillomavirus vaccine display a range of Alpha-9 inter-type specificities

The highly efficacious human papillomavirus (HPV) vaccines contain virus-like particles (VLP) representing genotypes HPV16 and HPV18, which together account for approximately 70% of cervical cancer cases. Vaccine-type protection is thought to be mediated by high titer, type-specific neutralizing antibodies. The vaccines also confer a degree of cross-protection against some genetically-related types from the Alpha-9 (HPV16-like: HPV31, HPV33, HPV35, HPV52, HPV58) and Alpha-7 (HPV18-like: HPV39, HPV45, HPV59, HPV68) species groups. Cross-protection is coincident with the detection of low titer serum responses against non-vaccine types by vaccinees. Such antibodies may be the effectors of cross-protection or their detection may be useful as a correlate or surrogate.