Days after the Union Health Ministry ordered an inquiry into the Type-2 polio virus contamination detected in the vials used for immunisation in Uttar Pradesh, Maharashtra and Telangana and ordered for additional immunisation in the three States, the ministry on Wednesday issued a statement stating that “India was certified polio-free in March 2014 and continues to be so. India continues to remain vigilant against all three types of polioviruses.”
“Recently, type 2 polio vaccine virus was found in some sewage and stool samples. The detection of type 2 vaccine virus indicates that a very robust polio surveillance jointly managed by Union Health Ministry and World Health Organisation is still maintained even though seven years have elapsed since the last wild poliovirus case in the country was reported. This detection indicated the use of a type 2 poliovirus containing vaccine, despite the fact that the trivalent Oral Polio Vaccine (tOPV) that contained type 2 poliovirus vaccine had been phased out globally, and in India, in April 2016, as a part of the Polio End Game strategy,” said the release.
The ministry further added that it was found that in a few vials of bivalent Oral Polio Vaccine (bOPV) supplied by one manufacturer, there were traces of P2 vaccine.
“The ministry, taking WHO on board, took immediate and comprehensive action. Following the report, the use of all vaccines supplied by this manufacturer was immediately stopped in the country till investigation was completed,” the release said.
Additional legal samples of bOPV were immediately sent for testing to the Central Drug Laboratory in Kasauli, which confirmed the previous report of presence of traces of P2 polio vaccine virus. The Drugs Controller General of India immediately filed an FIR and issued notice to the company asking it to stop manufacturing and supplying till further orders. The MD of the company was immediately arrested,” noted the release.
The Ministry further said that 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 fecal route for about 4-6 weeks after which it will die down.
``In small areas where such vials were used, polio surveillance in environment and through stool collection has been significantly enhanced by Health Ministry with support from WHO and partners to keep constant vigil on the shedding of the polio vaccine virus,'' noted the release adding that to enhance immunity against type 2 poliovirus further, special mop up rounds for administering IPV are being conducted in the specified areas to reach out to such children who may have missed IPV. This would provide immunity to all the children against all the three types of polio virus including Type 2.