As a result of ongoing disease surveillance, the Global Polio Laboratory Network (GPLN) has confirmed that a child in Changara district, Tête province, Mozambique, was paralyzed by type 1 wild poliovirus (WPV1). 

The child experienced onset of paralysis on 25 March 2022, and sequencing of the virus confirms that it is linked to the imported WPV1 case confirmed in Malawi in February.  

While this detection of another WPV1 in the southeast Africa region is a concern, it is not unexpected following the Malawi detection in February and further underscores the importance for all countries to prioritize immunization of children against polio. 

Mozambique has participated in the multi-country coordinated vaccination campaigns in response to Malawi’s imported WPV1, with two vaccination rounds already conducted. The most recent took place at end of April, with 4.2 million children vaccinated across the country, and the Global Polio Eradication Initiative (GPEI) is supporting countries to strengthen disease surveillance and prepare for the remaining two campaign rounds. These will cover Malawi, Tanzania, Mozambique and Zambia, with Zimbabwe joining the later rounds to ultimately help reach over 23 million children under five years with polio vaccine by end of August 2022. 

Mozambique last recorded a case of wild polio in 1992 though the country has more recently been affected by an outbreak of circulating vaccine-derived poliovirus type 2 (cVDPV2). Three cases have been detected since April 2021 and vaccination campaigns in response to the outbreak are continuing, which include use of the novel oral polio vaccine type 2 (nOPV2).  

Wild polio remains endemic in just two countries – Pakistan and Afghanistan. The WPV1 detection in Mozambique does not affect the WHO African Region’s wild poliovirus-free certification status officially marked in August 2020, as the virus strain originated in Pakistan. However, any child paralysed by polio is one too many. The polio eradication programme has seen importations from endemic countries to regions that have been certified wild poliovirus-free in the past and has moved quickly to successfully stop transmission of the virus in these areas. 

Polio anywhere is a threat to children everywhere. It is vital that all parties ensure that the GPEI has the support it needs to implement its five-year eradication Strategy in full and ensure no child is paralysed by polio ever again.

April 2022 – Convening this month in Geneva, Switzerland, the Strategic Advisory Group of Experts on immunization (SAGE), the global advisory body to the World Health Organization (WHO) on all things immunization, urged concerted action to finish wild polioviruses once and for all.

The group, reviewing the global wild poliovirus epidemiology, highlighted the unique opportunity, given current record low levels of this strain. At the same time, it noted the continuing risks, highlighted in particular by detection of wild poliovirus in Malawi in February, linked to wild poliovirus originating in Pakistan.

On circulating vaccine-derived poliovirus (cVDPV) outbreaks, SAGE expressed concern at continuing transmission, in particular in Nigeria which now accounts for close to 90% of all global cVDPV type 2 cases, as well as the situation in Ukraine, and its disruption to health services, urging for strengthening of immunization and surveillance across Europe.  It also noted the recent detection of cVDPV type 3 in Israel in children, and in environmental samples in occupied Palestinian territories, and urged high-quality vaccination activities and strengthened surveillance.

Preparing for the post-certification era, the group underscored the importance of global cessation of all live, attenuated oral polio vaccine (OPV) use from routine immunization, planned one year after global certification of wild poliovirus eradication.  To ensure appropriate planning, coordination and implementation, the group endorsed the establishment of an ‘OPV Cessation Team’, to consist of wider-than-GPEI stakeholder participation and ensure leadership on all aspects of OPV cessation.

SAGE will continue to review available evidence and best practices on a broad range of GPEI-related programmatic interventions, including as relevant the increasing role of inactivated polio vaccine (IPV), including in outbreak response and effects of novel oral polio vaccine type 2 (nOPV2), as part of global efforts to secure a lasting world free of all forms of poliovirus.