Insights into human papillomavirus surveillance in Ireland using residual unlinked clinical samples

Problem

Ireland has delivered a national, school‑based human papillomavirus (HPV) vaccination programme since 2010, moving to a single‑dose schedule in 2022. In the absence of population‑level monitoring of vaccine impact on HPV prevalence the need to establish a population‑based surveillance system was identified.

Description of the problem

A scoping exercise was led by the Health Protection Surveillance Centre, in collaboration with key stakeholders, to identify the most appropriate methodology for assessing the impact of HPV vaccination in Ireland. Following a review of international surveillance models and engagement with international colleagues from existing surveillance programmes, monitoring HPV genotype prevalence and distribution using residual unlinked clinical specimens was identified as the preferred approach. In 2024, an amendment to the Infectious Disease Regulations designated HPV infection detected in residual unlinked specimens as notifiable, providing a clear statutory basis for this form of surveillance. In parallel, scoping was conducted to identify suitable residual clinical specimen sources for extended HPV genotyping, including samples from sexual health services and the national cervical screening programme.

Results

Through expert consensus it was agreed that surveillance of HPV genotype prevalence and distribution, aimed at monitoring vaccine impact and the potential emergence of replacement genotypes in Ireland, is best delivered through extended genotyping of unlinked residual samples from the national cervical screening programme.

Lessons

The use of unlinked residual cervical screening samples provides population‑level coverage and leverages established laboratory infrastructure within existing public health governance arrangements. Further work is underway to pilot this approach and assess the feasibility of delivering it as a sustainable surveillance programme, with lessons learned informing future surveillance programme development.

Key messages

• Development of a national HPV genotype surveillance programme in Ireland to monitor the impact of HPV vaccination and the potential emergence of replacement genotypes in the population.

• Development of HPV genotype surveillance in Ireland using unlinked residual cervical screening samples to monitor the prevalence and distribution of HPV genotypes and the impact of vaccination.