Human Papillomavirus Genotype Replacement: Still Too Early to Tell?

Abstract

BACKGROUND:

Although human papillomavirus (HPV) vaccines are highly efficacious in protecting against HPV infections and related diseases, vaccination may trigger replacement by nontargeted genotypes if these compete with the vaccine-targeted types. HPV genotype replacement has been deemed unlikely, based on the lack of systematic increases in the prevalence of nonvaccine-type (NVT) infection in the first decade after vaccination, and on the presence of cross-protection for some NVTs.

METHODS:

To investigate whether type replacement can be inferred from early postvaccination surveillance, we constructed a transmission model in which a vaccine type and an NVT compete through infection-induced cross-immunity. We simulated scenarios of different levels of cross-immunity and vaccine-induced cross-protection to the NVT. We validated whether commonly used measures correctly indicate type replacement in the long run.

RESULTS:

Type replacement is a trade-off between cross-immunity and cross-protection; cross-immunity leads to type replacement unless cross-protection is strong enough. With weak cross-protection, NVT prevalence may initially decrease before rebounding into type replacement, exhibiting a honeymoon period. Importantly, vaccine effectiveness for NVTs is inadequate for indicating type replacement.

CONCLUSIONS:

Although postvaccination surveillance thus far is reassuring, it is still too early to preclude type replacement. Monitoring of NVTs remains pivotal in gauging population-level impacts of HPV vaccination.

• Authors: Irene Man, Simopekka Vänskä, Matti Lehtinen, Johannes A Bogaards
• Journal: The Journal of infectious diseases (J Infect Dis) Vol. 224 Issue 3 Pg. 481-491 (08 02 2021) ISSN: 1537-6613 [Electronic] United States
• PMID: 31985011 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.

Chemical References

• Papillomavirus Vaccines

Topics

• Alphapapillomavirus (genetics)
• Genotype
• Humans
• Papillomaviridae (genetics, immunology)
• Papillomavirus Infections (epidemiology, prevention & control)
• Papillomavirus Vaccines
• Vaccine Efficacy