Immunize with IPV
About the vaccine
Inactivated Poliovirus Vaccine (IPV) is key to the polio endgame. To safeguard against the withdrawal of the type 2 serotype, in November 2012 the SAGE recommended that at least one dose of IPV be introduced into all routine immunization programmes prior to the switch from tOPV to bOPV.
This IPV dose is expected to:
•prevent paralytic polio in individuals exposed to a cVDPV type 2 or WPV2;
•improve the immunological response to mOPV type 2 if required to be given in response to a WPV2 or cVDPV2 outbreak after tOPV cessation;
•reduce transmission of cVDPV type 2 or WPV2 should either be introduced after tOPV cessation;
•boost immunity to WPV1 and WPV3 in vaccine recipients, which may further accelerate WPV eradication.
IPV provides serum immunity to all three types of poliovirus, resulting in protection against paralytic poliomyelitis. As an injectable vaccine, it can be administered alone or in combination with other vaccines.
There is enough production capacity for current IPV standalone products to meet the needs for all OPV-using countries to introduce one dose of IPV into their routine immunization programme. However, to ensure sufficient IPV is available when countries are ready for its introduction, it is essential that all countries define their target introduction dates as soon as possible (i.e. by mid to end-2014 latest).
IPV product pipeline
Currently, IPV is prequalified by WHO as a stand-alone vaccine in 1-dose, 2-dose and 10-dose presentations. WHO expects a 5-dose presentation to be available in 2014.
These products are preserved with 2 phenoxy-ethanol. This means that any open vials of this vaccine must be discarded at the end of the immunization session or six hours after opening, whichever comes first. These vaccines are licensed for use as a 0.5 ml dose administered intramuscularly.
IPV-containing combination presentations with diphtheria, tetanus, acellular pertussis, hepatitis B, or Hib antigens in tetravalent, pentavalent, or hexavalent formulations are also available but at substantially higher cost. A combination product with whole-cell pertussis is not currently available.
Safety and effectiveness
IPV is an extremely safe vaccine. It is produced from killed poliovirus serotypes and does not pose the low level risks associated with the oral vaccine. Adverse events following administration of IPV are very mild and transient.
Due to the risks associated with the large quantities of poliovirus needed for IPV production, following the global cessation of poliovirus transmission high level (BSL-3/polio) containment of all manufacturing and quality control areas where live virus is handled must be implemented.
IPV has been used successfully in the polio eradication programmes of a few countries, notably in Scandinavia and the Netherlands. Most studies indicate that the degree of mucosal immunity in the intestine is significantly less than that provided by OPV, although this difference may be less pronounced in the pharyngeal mucosal lining.