 Being inactivated, the IPV is free of these risks but does not induce contact immunity.IPV is more costly and the logistics of delivery are more challenging.The 175 diagnosed wild polio virus (WPV) cases worldwide in 2019 represented the highest number of cases since 2014, but still a reduction from the 719 diagnosed cases in 2000 and a reduction from the estimated 350,000 cases when the eradication effort began in 1988.