Allergic reaction to the vaccine
Inactivated polio vaccine can cause an allergic reaction in a few people since the vaccine contains trace amounts of antibiotics, streptomycin, polymyxin B, and neomycin. It should not be given to anyone who has an allergic reaction to these medicines. Signs and symptoms of an allergic reaction, which usually appear within minutes or a few hours after receiving the injected vaccine, include breathing difficulties, weakness, hoarseness or wheezing, heart rate fluctuations, skin rash and dizziness. Vaccine-induced polio
A potential, adverse effect of the OPV is its known ability to recombine to a form that causes neurological infection and paralysis. This genetic reversal of the pathogen to a virulent form takes a considerable time (at least 12 months) and does not affect the person who was originally vaccinated. The vaccine-derived attenuated virus is normally excreted from vaccinated people for a limited period. Thus, in areas with poor sanitation and low vaccination coverage, the spontaneous reversal of the vaccine-derived virus to a virulent form and its spreading in the environment can lead to unvaccinated people becoming infected. Clinical disease, including paralysis, caused by vaccine-derived poliovirus (VDPV) is indistinguishable from that caused by wild polioviruses. Outbreaks of vaccine-associated paralytic poliomyelitis (VAPP), caused by a circulating vaccine-derived poliovirus (cVDPV), have been reported, and tend to occur in areas of low coverage by OPV, presumably because the OPV is itself protective against the related outbreak strain.
The fact that the CIA organized a fake vaccination program in 2011 to help find Osama Bin Laden is an additional cause of distrust. In 2015, the WHO announced a deal with the Taliban to encourage them to distribute the vaccine in areas they control. However, the Pakistani Taliban was not supportive. On 11 September 2016, two unidentified gunmen associated with the Pakistani Taliban, Jamaat-ul-Ahrar, shot Zakaullah Khan, a doctor who was administering polio vaccines in Pakistan. The leader of the Jamaat-ul-Ahrar claimed responsibility for the shooting and stated that the group would continue this type of attack. Such resistance to and scepticism of vaccinations has consequently slowed down the polio eradication process within the two remaining endemic countries. Travel requirements
Travellers who wish to enter or leave certain countries must be vaccinated against polio, usually at most 12 months and at least 4 weeks before crossing the border, and be able to present a vaccination record/certificate at the border checks. : 25–27  Most requirements apply only to travel to or from so-called polio-endemic, polio-affected, polio-exporting, polio-transmission, or high-risk countries. As of August 2020, Afghanistan and Pakistan are the only polio-endemic countries in the world (where wild polio has not yet been eradicated). Several countries have additional precautionary polio vaccination travel requirements, for example to and from key at-risk countries, which as of December 2020 include China, Indonesia, Mozambique, Myanmar, and Papua New Guinea.