Get latest articles and stories on World at LatestLY. Zimbabwe began an emergency campaign to inoculate more than 4 million children against polio on Tuesday after health authorities detected three cases caused by the rare mutation of the weakened virus used in oral vaccines, including a 10-year-old girl who was paralysed in January. World News | Zimbabwe Starts an Emergency Polio Vaccination Drive After Detecting Cases Caused by a Rare Mutation.