HPV vaccine: starting at 9 or 10 means more children are fully vaccinated

When should vaccination against human papillomavirus (HPV) begin? A team led by Allison Kempe and Sean O'Leary of the University of Colorado Anschutz examined this in a cluster-randomised trial in 31 paediatric practices in Colorado and California. Some practices offered the vaccine from age 9 to 10, the rest – as is usual in the US – from 11 to 12. The trial ran from October 2021 to April 2026 and was presented at the IDWeek infectious diseases meeting in Washington; so far it is available as a preprint that has not yet been peer-reviewed. It was funded by the US National Cancer Institute (NCI).

The result: by their 13th birthday, 61.6 per cent of children in the early-start practices had completed the vaccine series, compared with 45.1 per cent in the comparison practices. By that age, 77.1 per cent versus 67.0 per cent had started it. The median age at completion was 12.2 rather than 13.3 years. Other routine vaccinations were not affected. O'Leary told the medical news site Healio that the earlier start had led to statistically significant and clinically meaningful gains. Physician Kengo Inagaki (University of Michigan), who assessed the findings for Healio, stressed, however, that an early start will not eliminate vaccine hesitancy or access barriers.

The authors acknowledge limitations: only two states and no rural practices were included, and children who left a practice could not be followed. In addition, the study measures vaccination rates, not protection against disease. In Germany, the Standing Committee on Vaccination already recommends HPV vaccination for children aged 9 to 14, ideally before first sexual contact; health insurers cover it up to age 18, AOK NordWest explains. In Bulgaria, the national programme for preventing HPV-related cancers (2025–2030) offers free vaccination from age 10 – for girls aged 10 to 17 and boys aged 10 to 13.