Polio virus in Kolkata sewage came from vaccinated individual, not cause for alarm, says WHO - ThePrint

India faces a 'threat' of importation of wild and vaccine-derived polio viruses, but Kolkata sample not a public health worry, according to World Health Organization.

Kolkata: Traces of the polio virus found in a sewage sample from Kolkata were vaccine-derived and likely to have been excreted by an immune-deficient individual, according to a World Health Organizat… [+4033 chars]

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