Polio vaccines: WHO position paper--June 2022/ Vaccins antipoliomyelitiques: note de synthese de l'OMS--juin 2022.

Citation metadata

Date: June 24, 2022
From: Weekly Epidemiological Record(Vol. 97, Issue 25)
Publisher: World Health Organization
Document Type: Article
Length: 23,712 words
Lexile Measure: 1750L

Document controls

Main content

Article Preview :

Introduction

In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale vaccination programmes. They summarize essential background information on diseases and vaccines and conclude with the current WHO position on the use of vaccines worldwide.

The position papers are reviewed by external experts and WHO staff and endorsed by the WHO Strategic Advisory Group of Experts (SAGE) on Immunization (https://www.who.int/groups/strategic-advisory-group-of-experts-on-immunization). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) method is used to assess the quality of the available evidence systematically. The SAGE decision-making process is reflected in "evidence-to-recommendation" tables. The processes followed for the preparation of WHO vaccine position papers are described at: https://www.who.int/publications/m/item/ guidance-for-the-development-of-evidence-based-vaccine-related-recommendations. The position papers are intended for use mainly by national public health officials and managers of immunization programmes. They may also be of interest to international funding agencies, vaccine advisory groups, vaccine manufacturers, health professionals, researchers, the scientific media and the general public.

This WHO position paper on polio vaccines supersedes the previous iteration published in the Weekly Epidemiological Record on 25 March 2016. (1) It summarizes developments in the polio programme after the globally synchronized "switch" from trivalent to bivalent oral poliovirus vaccine (OPV) which took place 17 April-1 May 2016. Recommendations from this position paper provide updated guidance on the use of polio vaccines in national immunization programmes. Recommendations regarding polio vaccines and schedules are discussed biannually by SAGE; evidence presented at these meetings can be accessed at: https://www.who.int/groups/ strategic-advisory-group-of-experts-on-immunization/ meetings.

Background

Epidemiology

Poliomyelitis (polio) is a highly contagious acute disease caused by one of three poliovirus serotypes (poliovirus types 1, 2, or 3). Transmission can occur through faecal-oral and oral-oral routes, with faecal-oral transmission more common in areas with poor access to water and sanitation. Polio mainly affects children aged <5 years. Infected individuals excrete poliovirus through faecal and pharyngeal shedding, typically for 4 and 2 weeks respectively. (2) However, immunosuppressed individuals have been documented to excrete poliovirus for extended periods of time (see below).

In 1988, more than 350 000 cases of paralytic poliomyelitis were reported annually across 125 countries. At this time, the World Health Assembly established the Global Polio Eradication Initiative (GPEI) to achieve polio eradication by the year 2000. By the end of 2021, sustained efforts in polio vaccination worldwide had resulted in a decrease of more than 99.9% in the number of reported paralytic cases caused by wild poliovirus (WPV). The last cases of WPV type 2 (WPV2) were reported in October 1999 (India), and of WPV type 3 (WPV3) in November 2012 (Nigeria). Subsequently, global eradication of WPV2 was certified on 20 September 2015, and of WPV3 on 24 October 2019. In 2021, 6 WPV type 1 (WPV1) cases were reported, with only 2 endemic countries, Afghanistan and Pakistan. (3)

In 2016, there was...

Source Citation

Source Citation   

Gale Document Number: GALE|A709490745