Incidence and duration of human papillomavirus infections in young women: insights from a bimonthly follow-up cohort.

Background: We studied the duration of HPV detection and risk of (re-) detection for 25 HPV genotypes in a cohort of 132 women followed every eight weeks for up to two years between 2016 and 2020. Participants were between 18 and 25 years old at inclusion and half of them were vaccinated against HPV. They were recruited near the University and the STI detection centre in Montpellier, France.

Methods: We used genotype-specific longitudinal data to characterise the dynamics of HPV-detected episodes. We investigated the contribution of viral and host factors to the variations in the duration of HPV detection, and the time before (re-)detection of the same genotype using multivariate Cox regression models with frailty at the patient level.

Findings: We detected at least one HPV episode in 74% of the participants and re-detected the same genotype in 47% of them. Covariates related to socio-economic difficulties were associated with a lower risk of detectability loss (hazard ratio 0.45 with a 95% confidence interval, CI, from 0.21 to 0.97). The number of lifetime sexual partners was strongly associated with an increased risk of new positive detection (hazard ratio 2.40 with a 95%CI from 1.07 to 5.39). In contrast, vaccination was associated with a lower risk of displaying incident infections (hazard ratio of 0.64 with a 95%CI from 0.43 to 0.96).

Conclusion: In the short term, vaccination shows clear signs of protection against new HPV detections, including for some genotypes not targeted by the vaccine, such as HPV31 and HPV51.