Recommendations for Reporting on Poliovirus Outbreaks

A media guide for journalists writing about circulating vaccine-derived polioviruses (cVDPVs) and polio eradication.

Overview

The media have an important role to play in communicating about one of the most complex challenges facing global polio eradication efforts: the spread of circulating vaccine-derived poliovirus (cVDPV) outbreaks in areas where immunization rates are low. This guide is intended to support media reporting on cVDPVs to ensure coverage does not inadvertently cause vaccine hesitancy, mistrust, or other unintended adverse consequences to public health and use of polio vaccines. Vaccination efforts that achieve and maintain a high level of coverage (85% or higher) within at-risk populations are critical to stopping all forms of polio and finally achieving eradication of the disease.

CVDPVS: Asked and Answered

What are cVDPVs?

A child cannot get cVDPV infection from receiving a polio vaccine. cVDPVs emerge when not enough children are vaccinated against polio, and the weakened strain of the poliovirus contained in the oral polio vaccine (OPV) circulates among under-immunized populations for a long time in areas with poor sanitary conditions. The weakened strains are shed by vaccinated children into the environment via their digestive systems and can pass from one unvaccinated individual to another, a process exacerbated by poor sanitation systems and the absence of clean drinking water. Over time, genetic changes in the virus can result in reversion to a form that can cause paralysis. cVDPVs are different from wild polioviruses, which now only circulate in Pakistan and Afghanistan. The rise in cVDPV cases, however, poses a risk to children, threaten eradication efforts and, just like wild polio, must be stopped.

What causes cVDPV outbreaks?

cVDPV outbreaks are caused by community-level immunity gaps, where both routine immunization and door-to-door campaigns have and issues accessing high-risk groups such as mobile populations. About 90% of cVDPV outbreaks are caused by type 2 cVDPV.

• In 2020, the March-July suspension of polio campaigns to protect communities and staff from COVID-19, coupled with related disruptions to routine immunization, created immunity gaps that led to new outbreaks of cVDPVs and further increased transmission of cVDPVs globally.

Where are outbreaks happening?

Most cVDPV outbreaks are in Africa, although there are also cases in parts of Asia, the Middle East and Eastern Europe. For the latest cVDPV case counts, see the GPEI’s cVDPVs page.

How are outbreaks stopped?

As with wild polio, outbreaks of cVDPVs are stopped by ensuring every child is reached with oral polio vaccine through high-quality immunization campaigns to close immunity gaps. Fast, high-quality vaccination campaigns using type 2 monovalent OPV (mOPV2) have stopped cVDPV2 outbreaks previously. The vaccine continues to be a safe, effective tool for outbreak response across the continent. In addition, the novel oral polio vaccine type 2 (nOPV2) is now being rolled out in several countries affected by cVDPV2 to help more sustainably stop outbreaks.