Evaluation of the immune response to human papillomavirus types 16, 18, 31, 45 and 58 in a group of Colombian women vaccinated with the quadrivalent vaccine

Abstract Objective To analyze whether the immune response to HPV-16, -18, -31, -45 and -58 capsids in women vaccinated with the quadrivalent vaccine induces cross-reactivity against other HPV virus-like particles (VLPs). Methods A total of 88 women aged between 18 and 27 years attending the HPV clinic at the Instituto Nacional de Cancerologia were enrolled and vaccinated against HPV. Follow-up visits were scheduled at months 7, 12, and 24. Samples were collected for cytology, HPV-DNA typing, and detection of HPV antibodies. IgG antibodies were measured by ELISA using HPV-16, -18, -31, -45, and -58 VLPs. HPV-DNA detection was done by GP5+/GP6+PCR-ELISA and HPV typing was performed by Reverse Line-Blot assay. Results Pre-vaccination, the seroprevalence of HPV-16, -18, -31, -45, and -58 was 39%, 31.7%, 15.9%, 31.7%, and 23.2%, respectively. One month post-vaccination, the seroprevalence increased close to 100% for all types. At month 24, this response was maintained only for HPV-16 and -18. For HPV-31, -45 and -58, the seroprevalence decreased to below 50%. The prevalence of HPV DNA types 16, 18 and 58 before vaccination was little changed 1 month after vaccination. No new infections were observed at 24 months. For HPV-16 and -18 related types, no differences were observed before vaccination and at month 24. For other high-risk HPV types, the prevalence increased 18 months post-vaccination (15.5%) compared with pre-vaccination (9.8%) Conclusion Immune response to all HPV types increased after vaccination, but this increase was maintained only for HPV-16 and -18. These results suggest a possible cross-reactivity against HPV types 31, 45 and 58, but this cross-reactivity wanes with time.