Polio Continues Spreading in Various Countries

The 28th meeting of the Emergency Committee under the International Health Regulations on the international spread of poliovirus reviewed updated data on wild poliovirus (WPV1) and circulating vaccine-derived polioviruses (cVDPV) on May 4, 2021.

On May 21, 2021, this World Health Organization (WHO) Committee announced it unanimously agrees that the risk of international spread of poliovirus remains a Public Health Emergency of International Concern (PHEIC) and recommended the extension of Temporary Recommendations for an additional three months.  

The Committee recognizes the concerns regarding the lengthy duration of the polio PHEIC. 

Still, it concludes that the current situation is extraordinary, with a clear ongoing substantial risk of international spread and the utmost need for a coordinated international response.

The Committee noted that the current situation provides an excellent opportunity over the next six months to curb the WPV1 transmission by implementing high-quality vaccination activities and fast-track progress towards global WPV1 eradication.

Furthermore, since its last meeting in February 2021, the Committee noted that cVDPV2 spread to Senegal and Kenya had been confirmed, and a new cVDPV1 outbreak has been reported in Madagascar. 

Despite an overall decreasing trend in the number of cVDPV2 cases in 2021 so far, a significant number of countries (11) remain infected in the African and Eastern Mediterranean regions during the first quarter of the year. 

Moreover, the Global Polio Laboratory Network analysis of the most recent quarterly routine analysis indicates cVDPV2 exportation to various countries.

The Committee noted that the novel OPV2 had been introduced and delivered in two countries (Nigeria and Liberia), with an additional four countries to implement nOPV2 campaigns by the end of May. 

The WHO’s Strategic Advisory Group of Experts on immunization has endorsed, in principle, nOPV2 to become the vaccine of choice for response to cVDPV2 outbreaks after review of the initial use period is completed, and all requirements for use are met.

The Committee noted that there are currently 60 million doses of nOPV2 in the stockpile, and it is expected to have an additional 252 million nOPV2 doses by the end of the year to support its wider use. 

In addition, trivalent OPV (tOPV) remains available on the advice of the OPV2 Advisory Group and approval by the WHO Director-General for use in countries that have concurrent type 1 and type 2 poliovirus infections co-circulating and is being used in both Pakistan and Afghanistan. 

About 2.5 million doses of tOPV currently available in the stockpile, and orders are in place for about 140 million additional doses by December 2021. 

Monovalent OPV2 (mOPV2) also remains available to be utilized to respond to the cVDPV2 outbreaks on the advice of the OPV2 Advisory Group and the approval of the WHO Director-General. 

Currently, 149 mOPV2 doses are available in the stockpile, and orders are in place for additional 175 million doses until December 2021.

Based on the updated GPEI guidance, the polio vaccination campaigns have mostly been resumed under good coordination among the polio eradication and COVID-19 management structures and coordination entities.

Separately, the U.S. CDC issued Level 2 Travel Alerts regarding countries with polio outbreaks. 

On May 13, 2021, the CDC suggested future visitors to certain countries in Asia and Africa should speak with a healthcare provider regarding polio vaccination options before traveling abroad.

Since 2000, the inactivated polio vaccine is most often given in the USA. The oral polio vaccine is offered in other countries, says the CDC.

Vax-Before-Travel publishes research-based polio vaccine news.