The scientific rationale for IPV introduction
The documents on this page provide scientific and technical background related to the introduction of IPV and the switch from trivalent OPV (tOPV) to bivalent OPV (bOPV). These documents provide an overview of Objective 2, recommendations by WHO and technical information related to scheduling and multiple injections.
WHO IPV Recommendations
Scheduling of IPV
To minimize the risks associated with the withdrawal of type 2 containing OPV, WHO recommends that all countries introduce at least one dose of Inactivated Poliovirus Vaccine (IPV) into their routine immunization schedule by the end of 2015. The IPV dose should be administered at 14 weeks of age or the nearest immunization visit after that.
For example, in countries with a routine DTP vaccine schedule of 6, 10, and 14 weeks of age, IPV should be given at 14 weeks with DTP3, or for countries with a 2, 3, and 4 month schedule, IPV should be given at 4 months. The IPV dose should be given in addition to all other scheduled vaccine doses, including OPV, and doing so, may require multiple vaccine injections.
A catch-up strategy, targeting children that have already been immunized with three doses of Penta/OPV, is not recommended for IPV because these children will have been vaccinated with tOPV, and thus immunized against all three types of polio, including type 2. It is also important to note that IPV should be administered at the first immunization contact after 14 weeks of age, and scheduling at 9 months or later is not recommended.
Multiple vaccine injections
Many countries have immunization schedules where children receive multiple vaccine injections at one visit. Globally, many middle and high-income countries have been safely using multiple injections for more than a decade. Vaccination schedules that involve multiple injections during the same visit are based on many years of pre-licensure and post-licensure safety and effectiveness data, including concomitant use studies.
As countries consider the potential implications of adding IPV to immunization schedules, the following resources may be helpful. Please also see the ‘Planning’ page for resources to support health worker training on multiple injections.
Poliovirus vaccination options for achieving eradication and securing the endgame (Estivariz, 2013)
Priming after a fractional dose of inactivated polio vaccine (Resik 2013)
Immunogenicity of supplemental doses of IPV (Estivariz, 2012)
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