The countrywide polio immunization drive began on Monday during which about 39 million children under the age of five will be administered anti-polio drops. Up to 260,000 polio workers are participating in the drive during which anti-polio drops are being administered to the children, sources said. Punjab Emergency Operation Coordinator for Polio Eradication Dr Munir Ahmed said Pakistan is very close to eradicating polio and keeping polio cases down to one in almost three years in Punjab is a great feat.