WHO’s database on polio cases hides more than it reveals Sub: Sci Sec: Health Context: WHO recently published a report detailing a vaccine-derived poliovirus (VDPV) type-1 case identified from an environmental sewage sample in Kolkata on April 25, 2022. Genetic sequencing indicated that this virus was likely an immune-deficiency associated VDPV (iVDPV) excreted […]