New Delhi: The Health Ministry on Wednesday said that a special immunisation drive needs to be taken up in Hyderabad and Rangareddy districts of Telangana, following reports that poliovirus (P2 strain) has resurfaced in India. The ministry denied reports of the virus having resurfaced, and said that the polio virus strain detected is a vaccine-derived poliovirus (VDPV) in a sewage sample collected near the Secunderabad railway station. "India continues to be polio-free as the country has eradicated wild polio virus, and the last case was seen on January 13, 2011. It is more than five years that no wild poliovirus has been detected," said a statement from the Ministry. The Ministry also said that the last case of Wild Polio Virus Type 2 in the country was reported 17 years back in 1999. "The detection of vaccine derived polio virus (VPDV) does not change the polio-free status. It only indicates the robustness of the surveillance system and willingness of the country to detect any kind of poliovirus even from the environment (sewage)," said the statement, adding that vaccine-derived polioviruses are a rare strain of the polio virus that have genetically mutated from the strain contained in the Oral Polio Vaccine (OPV). The Ministry said that as a precautionary measure against Polio, a special immunization drive is being held, covering high-risk areas of Hyderabad and Rangareddy districts, starting from June 20, where an estimated 300,000 children will be protected against polio using Inactivated Polio Vaccine (IPV). "The special immunisation campaign will ensure all vulnerable children living in high-risk areas are given protection against polio. As part of the special campaign being organised now, children between the age group of six weeks to three years will be given an additional dose of the injectable polio vaccine (IPV). Vaccination booths will be set up in the areas being covered in these campaigns." The Ministry also said that there will be no door-to-door vaccination campaign.