Exploring the role of new and existing vaccines to support stopping transmission

The Global Polio Eradication Initiative (GPEI) continues to evaluate all vaccine options to accelerate polio eradication, including strategies of new vaccines and innovative use of existing vaccines. In November 2008, the Advisory Committee on Poliomyelitis Eradication (ACPE) recommended that the GPEI pursue a clinical evaluation of bivalent oral poliovirus vaccine (bOPV). Based on expert advice, the bOPV was formulated identical as to trivalent OPV (tOPV), except for the exclusion of Sabin type 2 poliovirus component. A clinical trial is currently underway in three sites in India, in Pune (Maharashtra), Indore (Madhya Pradesh) and Chennai (Tamil Nadu). Currently all required subjects have already been enrolled. The results from this trial are expected at the end of the first quarter of 2009. If the trial results are promising, licensure will be sought for this product, and the bOPV could then be used in areas where poliovirus types 1 and 3 are co-circulating.

As part of optimizing the use of different polio vaccines to close the immunity gaps against the three serotypes, and supported by a recommendation of the India Expert Advisory Group for Polio Eradication (IEAG) in 2008, the GPEI is planning to study to evaluate inactivated poliovirus vaccine (IPV) in late 2008 in northern India. The vaccines assessed will be fractional dose IPV (1/5th of a standard dose given intradermally), full dose IPV (administered intramuscularly) and monovalent oral poliovirus vaccine type 1 (mOPV1). If successful, fractional dose IPV could serve both as a cost-saving and supply-extending measure that could facilitate the inclusion of this vaccine for campaign use in known reservoir areas of wild-type poliovirus circulation.