WHO/BS/2017.2313 Report on the WHO Collaborative study to establish IS for potency assays of Oral Polio Vaccine
Overview
A collaborative study was conducted with an aim to establish the 1 st International Standards (IS) for monovalent (mOPV) and bivalent Polio (bOPV) vaccines. Candidate samples for bOPV 1+3, mOPV1, mOPV2 and mOPV3 were made from well characterised monovalent Polio bulks. These candidates have been allocated the following NIBSC code numbers bOPV 1+3: 16/164, mOPV1: 16/196, mOPV2: 15/296, mOPV3: 16/202.
The candidates were tested by a panel of global laboratories which included seven OPV manufacturers and seven National Control Laboratories. The bOPV 1+3, mOPV 1 and mOPV 3 candidates were tested in duplicate in the study. For the mOPV 2 candidate, due to the raised containment for Polio type 2 only four participants were eligible to undertake the testing, a total of ten vials were tested and 3 independent assays performed. Laboratories used both their validated methods for the bOPV 1+3 candidate using their in-house antisera for the neutralization element of the test (8 labs) and/or the NIBSC monoclonal antibodies F/D preparations provided (12 labs).
Given the suitability of the candidates and the consistency of the study it is recommended that each of the candidates serve as 1st International Standards with the following assigned potencies: bOPV 1+3 NIBSC code 16/164 - 7.19, 6.36 and 7.32 log10 TCID50/ml for type 1, 3 and Total Virus content respectively.