Research Summary

Does HPV Vaccination Prevent Transmission in Heterosexual Couples?

Miranda Manier, BA

Key Highlights:

  • This randomized controlled study evaluated human papillomavirus (HPV) incidence and transmission in 154 heterosexual couples based on sex and vaccination status.
  • Recent HPV vaccination appeared to reduce incidence in males but not in females.
  • There was no consistent evidence that recent vaccination reduced HPV transmission to a partner.
  • Findings suggest limited benefit from HPV vaccination for adults vaccinated after sexual debut.

A new study in the Journal of Clinical Virology investigated whether recent human papillomavirus (HPV) vaccination provides protection against infection or transmission in newly formed heterosexual couples. Drawing on data from the Transmission Reduction and Prevention with HPV Vaccination (TRAP-HPV) study, researchers observed lower incidence rates in vaccinated males but found no consistent evidence of protection for females or reduced transmission to partners.

Understanding HPV transmission dynamics between sexual partners is key for informing vaccination strategies. Previous studies have shown strong vaccine efficacy when administered before exposure, but less is known about its benefits when given after sexual debut. This study aimed to address that gap by following newly formed heterosexual couples randomized into four groups based on vaccination status: neither vaccinated, only the male vaccinated, only the female vaccinated, or both vaccinated.

Researchers enrolled 308 participants (154 couples) in Montreal between 2014 and 2022. Genital samples were collected at baseline and multiple follow-ups over 12 months and tested for 36 HPV types. Incidence and transmission rates were calculated for vaccine-targeted types, phylogenetically related types, and unrelated types. Time-to-event analyses at the HPV-type level provided detailed insight into infection risk by sex and vaccination status.

Among males, those who received recent HPV vaccination had lower point estimates for incident detection of vaccine-type HPV (0.99 and 1.67 events/1000 months) compared to unvaccinated males (2.42 and 3.35 events/1000 months). However, the wide confidence intervals and low event counts limited statistical certainty. In females, incidence rates did not show a clear protective trend. Transmission rates were inconsistent, and in some cases, unexpectedly higher in couples where both partners were vaccinated.

The study’s limitations include small sample size, wide confidence intervals, and a high rate of loss to follow-up, often due to relationship dissolution. Many participants were also already sexually experienced, and some may have had latent infections not preventable by vaccination. These factors may have masked protective effects.

“We did not find conclusive evidence of a protective effect from recent HPV vaccination against either incident infection or transmission for oneself or one’s partner,” Moore et al concluded. “Given the low number of events in each study arm and the well-established efficacy of HPV vaccination in preventing HPV infection, these findings should be interpreted with great caution and should not be generalized to younger or less sexually experienced populations. Future studies with larger sample sizes could yield further insights into the effects of HPV vaccination in sexually active adult populations.”

 

Reference:
Moore A, El-Zein M, Burchell AN, Tellier PP, Coutlée F, Franco EL. Human papillomavirus incidence and transmission by vaccination status among heterosexual couples. J Clin Virol. 2025;177:105779. doi:10.1016/j.jcv.2025.105779