Worldwide HPV Vaccination Coverage For Cervical Cancer Prevention

Silvia DE SANJOSÉ, Catalan Institute of Oncology, IDIBELL, L’Hospitalet de Llobregat, Spain
DIAZ M. 1 , BARRIONUEVO-ROSAS L. 1 , HERRERO R. 2 , BRAY F. 3 , BOSCH F. 1 , DE SANJOSÉ S. 1,4 , CASTELLSAGUÉ X. 1

1 Unit of Infections and Cancer, Cancer Epidemiology Research Program, Catalan Institute of Oncology, IDIBELL, L’Hospitalet de Llobregat, Barcelona, Spain
2 Prevention and Implementation Group, Section of Early Detection and Prevention, International Agency for Research on Cancer, Lyon, France
3 Cancer Surveillance Section, International Agency for Research on Cancer, Lyon, France
4 CIBER en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain

Purpose:
Since their licensure in 2006, HPV vaccines have been progressively introduced in many countries. By 2015, 64 countries have implemented national HPV vaccination programs and 37 have conducted demonstration projects.  However, the national guidelines, targeted ages, financing and delivery strategies differ considerably between countries and even within countries at regional level. We aim to describe and estimate actual global coverage considering all these variations.
Methods
Compilation of the most comprehensive database to date on publicly-funded National HPV Immunization Programmes, including: conversion of all retrieved coverages from multiple sources into birth cohort specific coverages, design of an imputation algorithm to treat missing data, and the use of global population estimates and projections. These procedures allow continuous monitoring and production of vaccination coverage trends, together with the use of cancer statistics to approximate the expected reduction on cervical cancer in vaccinated cohorts.
Results
About 118 million women have been targeted through these programmes, but only 1% from low or lower-middle income countries. 47 million (95%CI:39-55) women received the full course of vaccine and 59 million (95%CI:48-71) at least one dose. In more developed regions 33·5%(26·0-42·1%) of girls aged 10-20 years received the full-course, but only 2·7%(1·8-3·7%) in less developed regions. We estimated a reduction of about 380,000 future cervical cancer cases in these vaccinated cohorts. The expected impact will be higher for Latin American girls, despite a lower number vaccinated (13 million) compared to high income countries (32 million).
Conclusions
Despite the high number of girls successfully vaccinated between 2006 and 2014 worldwide (47 million), there are still many populations that have not yet had the possibility to be vaccinated. The monitoring of the worldwide HPV vaccination coverage will provide a critical tool to assess the expected impacts and benefits of this important prevention strategy.
Funding: PATH (USA); ISCIII, AGAUR(Spain)