Pakistan has built one of the world’s strongest polio control systems. Yet, 40,000 families in Karachi refused polio drops this year. In a city where the virus is detected in every district, these refusals show the remaining gap in Pakistan’s…

Pakistan has built one of the world’s strongest polio control systems. Yet, 40,000 families in Karachi refused polio drops this year. In a city where the virus is detected in every district, these refusals show the remaining gap in Pakistan’s…