HPV Threat Declines Among Vaccinated Women

But some high-risk strains persist, suggesting screening strategies need re-evaluation.

A recent study in Denmark reveals a significant decrease in HPV 16/18 prevalence among vaccinated women, signaling potential population immunity. However, the incidence of other high-risk HPV types remains a concern, potentially reshaping cervical cancer screening approaches.

Decline in High-Risk HPV Types

Before HPV vaccination programs began, high-risk HPV strains were present in all cervical cancers. Types 16 and 18, which are included in both the 4-valent and 9-valent HPV vaccines, accounted for approximately 74% of these cancers. After vaccination programs started, data indicates that HPV16/18 has been almost eliminated among vaccinated women in Denmark. The prevalence of HPV types 16/18 in vaccinated women’s samples fell to less than 1% in 2021, from 15–17% before vaccination.

Study Details

The research, published in Eurosurveillance, was conducted by **Nonboe et al.** and examined cervical samples from women aged 22–30, all of whom had been vaccinated as girls. Between February 2017 and February 2024, over 17,000 women provided at least one cervical cell sample. The study compared the prevalence, persistence, and incidence of HPV among vaccinated and unvaccinated women.

Population Immunity Indicated

The prevalence of HPV types 16/18 in unvaccinated women remained at 5%, which the authors interpret as a “strongly indicates population immunity.” This suggests that vaccination not only protects individuals but also contributes to broader community protection.

Despite the success against HPV 16/18, about one-third of screened women still had infections from high-risk HPV types not covered by the vaccines. New infections with these types were more frequent in vaccinated than in unvaccinated women. According to the CDC, approximately 43 million HPV infections occurred in 2018, highlighting the ongoing need for comprehensive prevention strategies CDC.

Screening Strategies Reconsidered

Given the low prevalence of HPV16/18 among vaccinated women, **Nonboe et al.** suggest re-evaluating current cervical screening strategies. They noted a significantly higher incidence of non-vaccine high-risk HPV types among vaccinated women compared to unvaccinated women. Based on their findings, **Nonboe et al.** conclude that “less intensive screening seems reasonable until women vaccinated as girls with the 9-valent vaccine reach screening age, at which point screening should be reconsidered.”