As posted in the Deccan Herald
Paralytic polio – derived from oral polio vaccine (OPV) — used for vaccinating millions of children — has struck India to cripple a child in West Bengal within a week of the World Health Organisation (WHO) declaring the country free from the wild polio virus.
A case of vaccine derived polio virus (VDPV) type 2 has been confirmed in a five-month-old child in the Lalbagh block of Murshidabad district, reminding the health policy planner that the battle with polio is yet to be won.
However, there is a basic difference between the polio that struck the Bengal block and the virus that did not raise its ugly head in the country over the last one year. While the WHO recognition comes due to the effort to keep the country free from wild polio virus, the incident that occurred in West Bengal is a case of vaccine derived polio, which is rare but with the real danger of continuing with the oral polio vaccine for years without improving the overall immunisation scenario.
Even though the country was free from wild polio virus in 2011, there were seven cases of VDPV last year in Chhattishgarh, Rajasthan, Madhya Pradesh, Punjab, Orissa and Uttar Pradesh. While one child had congenital immune deficiency in Dhamtari district in Chhattisgarh, others lived in areas with low routine immunization coverage, according to the national polio surveillance being run by the Union Health Ministry and the WHO.
The classification, however, means little for the victims as both wild and vaccine-derived virus cause the same crippling paralysis in children.
In VDPV, the virus was derived from OPV due to prolonged intestinal infection and removal of certain beneficial genetic changes, veteran virologist T Jacob John said, adding that VDPV was similar to wild polio virus as it was neuro-virulent and could be transmitted easily.