The polio immunization campaign in the Gaza Strip is on track, the United Nations said in New York on Monday. Following the completion of the second of three phases, more than 446,000 children in the Gaza Strip have been reached in the fight against the highly contagious virus, UN spokesman Stéphane Dujarric said. This corresponds to almost 70% of the total number of 640,000 children to be vaccinated. The third phase, in which the children in the north of the Gaza Strip are to receive the oral vaccine, is to begin on Tuesday. However, some evacuation orders from the Israeli army in the area ar…