INTRODUCTION
Only
two countries in the world, Pakistan and Afghanistan, still have polio (74 in
2015 compared to 334 in 2014). Of the three polio viruses that cause paralytic
polio – p1, p2 and p3 – there has been no case due to p2 since 1999. Therefore,
the World Health Assembly has recommended a synchronized switch from trivalent
oral polio vaccine (tOPV) to bivalent oral polio vaccine (bOPV)that contains
only p1 and p3 vaccinesin all 156 OPV using countries and regions during 2
weeks in April 2016. April 25, 2016 is
the date for global switch from tOPV to bOPV. A key component of a successful
switch involves effective monitoring of health facilities
after the national switch date in all countries to ensure that tOPV is no
longer available for administration. This is a prerequisite for the global
certification of the eradication of the p2 virus.
