India confirms two cases of Polio from vaccine

From IndianExpress.com.

For the first time ever, India has confirmed two separate cases of vaccine-derived poliovirus (VDPV). The cases have been reported in a four-year-old boy in Assam’s Dibrugarh district and a two-year-old in Bihar’s Champaran district. 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.

Experts said VDPVs are “very rare” but there is nothing to worry. “They have been seen in many countries. Many VDPVs are isolate that do not progress any further. Those that do circulate respond readily to high quality immunisation response,” said Dr Hamid Jafari, project manager, WHO, National Polio Surveillance Project.

While the two cases are not related, investigations to determine the immunological and clinical status of both have been initiated. “The two cases are being investigated for any immunodeficiency disorder which may be the reason for the VDPV. Usually, it is seen in one having immunodeficiency or in areas with low population immunity,” said Dr Sunil Khaparade, Deputy Commissioner, Immunisation, Union Health Ministry.

“We have got to know that the boy in Assam is suffering from an underlying brain disorder. Stool surveys of close contacts and local community are being conducted to find out if VDPVs are circulating locally,” said a senior official.

Officials said the investigation results would help them decide on the number of vaccination rounds which may be conducted to protect the community. “The response strategies for wild poliovirus and VDPVs are the same and that is to immunise every child under the age of five. Global experience with VDPVs shows they can be rapidly stopped, with 2-3 rounds of high-quality, large-scale immunisation rounds,” said an official.