Polio should be history. When it swept the world last century it crippled and killed hundreds of thousands before the world fought back. An immunisation program saw the virus retreat from the developed world - then a concerted campaign in the ‘80’s all but wiped it out in the developing world. So why has Pakistan become a polio hotspot with cases on the rise? And why when vaccinators set out to administer preventative drops to children are they risking their own lives? In the cities and out in the rural reaches of this complicated country, suspicion and hostility against the polio eradication program is being fanned by religious extremists, including the Taliban.