Population-level impact and herd effects following human papilloma virus vaccination programs

Overall goals

1) update and summarise the most recent evidence about the population-level impact of girls-only HPV vaccination on HPV infections and anogenital warts diagnoses among girls, women, boys and men.
2) summarise new evidence about the population-level impact of girls-only HPV vaccination on CIN2+ among screened girls/women
3) compare the population-level impact of HPV vaccination on anogenital warts diagnoses and CIN2+ between countries including or not multiple age-cohort vaccination in their HPV vaccination programs.

Key UK Colleagues and Partners

NHS Greater Glasgow and Clyde, Public Health England, Jo’s Cervical Cancer Trust

International Partners

Dr Melanie Drolet & Dr Marc Brisson
Centre de recherche du CHU de Québec – Université Laval, Canada
Melanie.Drolet@crchudequebec.ulaval.ca

Sustainable development goals

• SDG 3 - Good health and well-being
• SDG 5 - Gender equality
• SDG 10 - Reduced inequalities

Funding source

Scottish Government, Canadian Institute of Health Research

Project origin

Through attendance at NSS-funded conferences, I began to generate partnerships with the aforementioned individuals.

Evidence of need

We decided that a systematic review and meta-analysis of all countries implementing HPV vaccine programmes would provide a global perspective of the impact of HPV vaccines with respect to dosing regimens; gender-neutral programmes and vaccine types.

Project areas

Health Protection

Project activities

In 2015, we published our first systematic review in Lancet Infectious Diseases entitled “Population-level impact and herd effects following human papilloma virus vaccination programmes: a systematic review and meta-analysis”. In June 2018, we performed a similar review but with updated literature and this has been submitted for peer-review to Lancet.

Changes

We did a systematic review and meta-analysis to assess the population-level consequences and
herd effects after female HPV vaccination programmes, to verify whether or not the high efficacy reported in randomised controlled clinical trials were materialising in real-world situations. This has been evidenced as has the impact of vaccine on reduced infection and disease in unvaccinated women through high uptake. Our data reveal the importance of maintaining high uptake of these vaccines, and the importance of gender-neutral HPV vaccine programmes.

Next steps

The results of this meta-analysis, cumulating data from >60 million individuals, show compelling evidence of the substantial impact of three-dose girls-only HPV vaccination programs with the quadrivalent or bivalent vaccines on high-risk HPV infection, anogenital warts and CIN2+ among women, and herd effects among boys and older women. It will be crucial to continue monitoring the population-level impact of HPV vaccination to examine the impact of changes in vaccination strategies (e.g., potential waning of vaccine efficacy over time with reduced-dose schedules, incremental benefit of gender-neutral or nonavalent vaccination) and to quantify the impact of vaccination in low- and middle-income countries.

Challenges

It has been very collaborative with little in the way of challenge.

Mitigating challenges

N/A

Partnership principles

• strategic
• respectful
• flexible

Project gains

• leadership
• teamwork
• awareness
• academic
• resilience