Immunization, Vaccines and Biologicals

IPV Introduction, OPV Withdrawal and Routine Immunization Strengthening

A health worker vaccinates a child against polio in Landhi town, Karachi.
© UNICEF Pakistan/2011/Asad Zaidi— in Karachi, Pakistan.

This site provides information on objective 2 of the Polio Eradication and Endgame Strategic Plan 2013-2018. Objective 2 seeks to hasten the interruption of all poliovirus transmission and, where possible, contribute to strengthening immunization services for the delivery of other lifesaving vaccines.

The Endgame Plan was developed in response to the World Health Assembly (WHA) in May 2012, which declared the completion of poliovirus eradication to be a “programmatic emergency for global public health”. Under objective 2,all trivalent oral polio vaccines (OPV) were replaced with bivalent OPV in all OPV-using countries across the world – setting the stage for eventually ending OPV use entirely. In addition, at least one dose of inactivated poliomyelitis vaccine (IPV) will be introduced into routine immunization programmes globally.

The OPV switch around the world: visit our photo story

In a two-week period from 17 April 2016, the globally synchronized switch from trivalent oral polio vaccine (tOPV) to bivalent oral polio vaccine (bOPV) took place in 155 countries and territories.

To see how the switch was implemented in different countries around the world, visit our interactive web site to explore a range of photos illustrating all of the efforts that took place.

The Switch in the Americas: a mini-documentary

To capture this monumental event in global health history, PAHO/WHO has created a mini-documentary video following the tOPV-bOPV switch.

This video will contribute to the Polio legacy in the Americas, explaining the fundamentals of why the world embarked on the switch journey, and how the countries in the Americas planned, implemented, and supervised this process.

Available in English and Spanish at links below.

Latest WHO position paper on polio vaccines

An updated WHO position paper on polio vaccine was issued in the Weekly Epidemiological Record in March 2016.

This paper supersedes the WHO position paper entitled " Polio vaccines: WHO position paper, January 2014".

The position paper can be found online at: Polio vaccines: WHO position paper, March 2016 in English, French and Russian.

Click the links below for more information:


An overview of Objective 2 on strengthening routine immunization, the introduction of IPV, and OPV withdrawal.


For more detail on the science behind the Endgame Plan, this section includes references to a range of literature and peer-reviewed articles.


This section provides resources on strengthening routine immunization as it relates to polio.


This section provides resources on IPV introduction:

  • Policy recommendations and guidance on planning for IPV introduction
  • Materials to support implementation, including logistics, training and communications
  • Background information, implementation experiences and materials available related to the fractional dose administration of IPV
  • Case studies from countries that have introduced IPV


Focused on the steps to OPV withdrawal, this section includes information on:

  • Rationale and timelines for the switch from trivalent OPV to bivalent OPV
  • Guidance and procedures for planning and implementing the switch
  • Step-by-step guidance and templates for monitoring and validation of tOPV withdrawal

If you have any questions or need more information about IPV introduction, OPV withdrawal and routine immunization strengthening, please contact

Status updates on country planning for IPV introduction

WHO, UNICEF, and partners, are in regular dialogue with countries to support effective preparations. Click below for a summary per country of the status of planning and introductions updated monthly.