Most Americans, it seems safe to say, derived a healthy measure of satisfaction from the news in 2011 that a team of Navy SEALs had killed Osama bin Laden. The cheers faded soon enough, however, for one group: public health professionals. That’s because killing the archterrorist had the unintended consequence of undermining their campaign to finally wipe polio off the face of the earth.

This offering from Retro Report recalls how the damage was acute for a while in Pakistan, where Bin Laden had holed up in the northern town of Abbottabad. To confirm his presence there, American intelligence agents took advantage of an anti-hepatitis program being run by a Pakistani doctor, Shakil Afridi. As part of this collaboration, Dr. Afridi collected DNA samples in Abbottabad and tried, without luck, to do so at the compound where Bin Laden was hiding. The Americans satisfied themselves through other means that they had the right target.

But they also inadvertently delivered a serious blow to the anti-polio drive in Pakistan, which some imams had already denounced as a plot to sterilize Muslims. With suspicions about their true intentions running high, vaccinators suffered. Eventually, the extreme distrust receded, but the damage had been done. It underlined the frustrations often endured by public health specialists in their attempts to conquer certain infectious diseases once and for all. Just when they seem within reach of the goal line, events have a way of stopping them short.

Retro Report, a series of video documentaries exploring major news stories of the past and their lasting repercussions, examines this issue through the prism of one of humankind’s greatest achievements: the eradication of smallpox four decades ago. That awe-inspiring triumph has long begged to be duplicated. Yet it stands alone. Smallpox remains the only infectious disease to have been globally extinguished.