Polio this week

Polio this week as of 27 April 2016

• This World Immunization Week, we are closer than ever to the target of a world free of polio, with just two remaining polio endemic countries- Afghanistan and Pakistan. 

• Around the world, countries that remain vulnerable to polio are continuing to vaccinate children and build immunity

The Trivalent to Bivalent Oral Polio Vaccine Switch

• Between 17 April and 1 May, the type 2 component of the oral polio vaccine (OPV) is being removed from use through a globally synchronized switch from the trivalent to bivalent oral polio vaccine. This is the first stage of objective 2 of the Polio Eradication and Endgame Strategic Plan 2013-2018 to withdraw OPV in a phased manner starting with the type 2 component following the eradication of wild poliovirus type 2 in September 2015.

• Follow a live update of which countries have undergone the switch at the Global Polio Eradication website (link at the end of this article). Learn more about why the switch is such an important part of ensuring a polio-free world through the series of videos on the web page.

• The following indicators are being carefully tracked to ensure the switch goes smoothly. As of 25 April:

  • 75 of 155 (48%) countries and territories have stopped using the trivalent oral polio vaccine.

  • Independent monitoring to ensure the switch goes smoothly has begun in 63 countries.

  • The National Validation Committee has received switch monitoring data from four countries: Tuvalu, Rwanda, Sao Tome and Burundi.

  • The WHO Regional Office has received the National Validation Report from one country: Tuvalu.  

Wild poliovirus type 1 and Circulating vaccine-derived poliovirus cases

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