ISLAMABAD: Eight new cases of vaccine-derived poliovirus (VDPV) were reported from Khyber Pakhtunkhwa and Punjab on Friday, increasing the tally to 33 in the country this year.

Of the total eight cases, six were found in KP, including two in Peshawar and one each in Khyber tribal area, Bannu, Nowshera and Lakki Marwat while two were reported from Punjab’s Faisalabad city.

Before these eight cases, a total of 25 vaccine-derived poliovirus cases were reported in the country in the current year.

This type of poliovirus was officially declared eradicated across the globe in 2016.

There are three types of poliovirus which are categorised as Type I, II and III. Decades ago, a vaccine named ‘Trivalent’ was used which contained all the three viruses. After eradication of Type II Virus in 2016, another vaccine ‘Bivalent’ was introduced. It contained only type I and III viruses. However, suddenly the cases of Type II Virus (VDPV) are being reported and it is feared that the virus might re-emerge.

In 2019, 22 cases of vaccine-derived poliovirus were reported in Pakistan.

Published in Dawn, March 28th, 2020