India vaccine trials prompt major strategic shift
A recently-completed multi-centre clinical trial in India (Chennai, Indore, and Pune), sponsored by Panacea Biotec Ltd, initiated based on a recommendation by the Advisory Committee on Poliomyelitis Eradication (ACPE) and with extensive technical and financial support by the World Health Organization (WHO), has demonstrated the non-inferiority of a bivalent (types 1 + 3) oral poliovirus vaccine (bOPV) compared with monovalent type 1 oral poliovirus vaccine (mOPV1) and monovalent type 3 oral poliovirus vaccine (mOPV3).
The trial also demonstrated the superiority of bOPV compared to the respective Sabin type 1 and 3 strains contained in the trivalent oral poliovirus vaccine (tOPV). Immediately after the trial results were available, the ACPE convened by conference call and reviewed the trial outcomes and current epidemiology of wild poliovirus globally. It concluded that the use of bOPV in supplementary immunization activities (SIAs) constitutes and important new tool for the Global Polio Eradication Initiative to complement the use of tOPV for routine immunization and SIAs as well as the use of mOPVs in SIAs. The clinical trial report was made available in July 2009 by the sponsor to other manufacturers interested in bOPV production.
To date, at least four manufacturers are seeking national licensure for bOPV and a process has been initiated to review in parallel the regulatory dossiers for WHO-prequalification of these products for United Nations purchase. It is anticipated that the first newly-licensed bOPV could be used in supplemental immunization activities as early as November 2009.
In addition, the Global Polio Eradication Initiative is also awaiting the results of another clinical trial that was conducted in Moradabad district, western Uttar Pradesh, India. The trial evaluated five arms, a regular- and higher-potency mOPV1 and three inactivated poliovirus vaccine (IPV) arms. Unprecedented collaboration by Panacea Biotec Ltd, the sponsor (with IPV-bulk supplied by the Netherlands Vaccine Institute), GlaxoSmithKline, and Sanofi Pasteur made the trial possible. The results of this trial should be available in mid-September 2009 and should answer the following questions:
- Is higher-potency mOPV1 more immunogenic than regular-potency mOPV1 in northern India?
- Does IPV have a role to play in closing remaining immunity gaps?
- Will a fractional dose of IPV (1/5th of a full dose) given intramuscularly by needle-free device perform as well as a full dose of IPV?
As with the case of bOPV, the ACPE will review the data on higher-potency mOPV1 and on full- and fractional-dose IPV as soon as these will be available. It is expected, depending on the outcome of this trial, that major strategic shifts in the use of these products should be anticipated (as is the case with bOPV). These clinical trials will help inform the finalization of the new Global Polio Eradication Initiative five-year Strategic Plan (expected for publication in January 2010).