VDPV case worries Bihar Health officials

After Dibrugarh district of Assam where type one Vaccine Derived Polio Virus (VDPV) was confirmed, another case of VDPV type two was reported from Bihar's East Champaran district, the first of its kind reported in India, State Polio Office sources confirmed on Wednesday.

Though the two cases are not related to each other, VDPVs are very rare but well-documented strains of poliovirus.

VDPVs are strains of the virus contained in the oral polio vaccine which have changed and reverted to a form that can cause paralysis in humans with the capacity for sustained circulation. These cases are very rare and occur in persons with immuno-deficiency or in areas with low population immunity, sources said.

East Champaran's Surveillance Medical Officer Dr Sushil Kumar Sinha disclosed that Rajiv Mallick, a two year-old boy of Baghi Bakhtaura village in the district, was not administered the doses of routine immunisation (RI) oral polio vaccine (OPV) which contains attenuated strains of all the three types of polio viruses (P1, P2, P3) to save children from polio caused by any of these three viruses.

Mallick, however, was administered polio vaccine during pulse polio rounds, through which immunisation from P1 and P3 types of polio viruses is done.

Dr Sinha said it appeared that the VDPV 2 virus infected Mallick after its mutation in the environment from the stool of someone who had been administered OPV during RI.link