Poliomyelitis is an exclusively human disease that mainly affects children. Clinical features of poliomyelitis can be varied, from mild illness to the most severe paralysis, and the factor why poliomyelitis has different performances in individuals has been proved strongly correlated with membrane protein CD155. The nervous system shows a special protecting phenomenon against the invasion of poliovirus, and the mechanism is not very clear at present. Vaccines are the main means of preventing and controlling polio, and many different vaccines have been invented in the process of fighting polio. Inactivated polio vaccine (IPV) and oral polio vaccine (OPV) are the two main vaccines. IPV is known for its safety while OPV is widely used in developing countries because of its relatively low cost. This usage also leads to some side effects: vaccine-associated paralytic polio (VAPP) and vaccine-derived poliovirus (VDPV). Now, for polio eradication, the elimination of these two diseases has become particularly important. Thus, a new type of vaccine was created: sequential IPV-OPV with the safety of IPV and the low cost of OPV. This paper will talk about the different polio vaccines and their effects. An enormous difference between people who have gotten the vaccine and people who have not got the vaccine. Comparing the two kinds of people, people who get normal poliovirus, and people who get poliovirus after taking a vaccine, known as VAPP (vaccine-associated paralytic poliomyelitis), the former cannot get full recovery whole life and the latter has a very low possibility. In conclusion, people should take vaccines if it is affordable for them.
