Not wild poliovirus but vaccine-derived poliovirus (VDPV) was detected in the environmental surveillance of sewage samples from Kolkata, said a senior Health Ministry official on Thursday. “The genetic sequencing is done at ICMR-National Institute of Virology, Mumbai, and this was discussed with the World Health Organisation (WHO). It can occur in any country where oral polio vaccine (OPV) is given,’’ added the official.
The Ministry said that the last time such a VDPV was detected was in New Delhi in 2018.
State health officials detected the presence of VDPV from sewage waters in Kolkata earlier this week. A VDPV is a strain of the weakened poliovirus that was initially included in OPV and that has changed over time and behaves more like the wild or naturally occurring virus.
