Some oral polio vaccines containing 1.5 lakh vials that were administered to children in three states – Maharashtra, Telangana and Uttar Pradesh – were contaminated with strains of type-2 poliovirus. The Ministry of Health and Family Welfare taking WHO on board took immediate and comprehensive action following reports that bivalent oral polio vaccine supplied by a particular manufacturer had some quality issues. These vaccines were manufactured by a Ghaziabad-based pharmaceutical firm Biomed.
The Health Ministry, which has already issued advisories to the three states, has also clarified that the type 2 polio vaccine virus traces found in vaccine vials is not likely to cause infection. “Type 2 polio vaccine virus traces which have been found in bOPV vials is the attenuated (weakened) poliovirus and does not cause paralysis and was also earlier used in tOPV till April 2016. The recipients of such vaccine will usually shed the vaccine virus through faecal route for about 4-6 weeks after which it will die down,” the health ministry said in a statement.