I got all three of my children vaccinated against polio, measles, tetanus and diphtheria. But around that time, an engineer I knew refused to do so. According to him, these vaccines were not necessary, they weakened the immunity of children, and were promoted by westerners to dupe the gullible people of the developed world. Then there was the mad cleric Fazlullah, who used to brainwash Pathan women into believing that polio drops would make their children infertile. According to his twisted logic, Anericans were enemies of Muslims, killing them in Afghanistan and Iraq, so why would they want Muslim children to be protected against a disease, unless it also made them unable to produce children? I have met several so-called "educated" men who also share this belief. 
When I meet such people I tell them of what happened in 1961, when a Pakistani flying from Karachi to London infected many Britishers with the smallpox virus, Within a couple of days, sixty people had died, and flights from Pakistan were stopped until the virus was controlled. 
And this is why, I tell the skeptics, Europeans and Americans want Pakistanis to be vaccinated against polio, so that their people will not be infected by polio-virus carrying Pakistanis visiting their countries.
But the resistance remains, and some more cases of children stricken by polio have been discovered in the country recently. Add to this the warning by the U.S. government to its nationals not to visit Pakistan because a super typhoid bug has emerged, which is resistant to antibiotics. I only hope this virus doesn't spread and kill more people (850 have died already).