HPV 2017 – 31st International Papillomavirus Conference (Cape Town)

Population-level impact of HPV vaccination program in high HIV prevalence settings

[Abstract HPV17-0835 ]

M.M. Rönn, M. Brisson, K. Looker, H. Kelly, P. Brock, P. Mayaud, M-C. Boily

HPV17-0835 Research Papers Session 08: Economics and Mathematical Modelling

Aims

Interactions between HIV and HPV can impact HPV vaccination programs in high burden areas. Our previous meta-analyses estimate 2.1-2.6-fold HPV acquisition (cofactor1) and 1.4-1.7-fold persistence of HPV (cofactor2) among HIV-infected individuals, and 1.6-2.9-fold HIV acquisition (cofactor3) among HPV-infected individuals. We aimed to investigate how HIV-HPV cofactors influence the population-level impact of 9-valent vaccination in high HIV prevalence populations/settings.

Method

We developed a transmission dynamic model with HIV and two HPV types (susceptible-infected-recovered with short-lived natural immunity) representing 9-valent vaccine (9vHPV) and non-vaccine high-risk (nvtHPV) types. We compared the long-term population 9vHPV prevalence following vaccination program (60% coverage in young girls; 95% life-long vaccine efficacy) in high HIV prevalence (>15%) setting. We varied cofactors 1-3, and heterogeneity in sexual risk (homogenous, low, medium, high) and mixing (proportionate, assortative).

Results

HPV and HIV prevalence is increased by sexual homogeneity and cofactors 1-3. Vaccination impact varies across scenarios and is reduced by HPV cofactors (figure), more in homogenous than in heterogeneous populations. HPV vaccination could indirectly reduce HIV prevalence by 5-11% (with cofactor3) but the effect is reduced by heterogeneity (not shown).

Conclusion

HIV-HPV cofactors can influence HPV vaccination impact to varying degree depending on risk heterogeneity. HPV vaccination may provide ancillary benefits for HIV in more homogenous population. HPV vaccination modeling needs to incorporate HIV transmission in generalized HIV epidemics to account for interactions.