Poliovirus is a member of the Picornaviridae family and is the causative agent of poliomyelitis, commonly known as polio. It is a small, RNA virus that primarily affects the nervous system and can lead to muscle weakness, paralysis, and in some cases, death. There are three serotypes of poliovirus: poliovirus type 1 (wild type), type 2 (wild type, declared eradicated as of 2015), and type 3 (wild type).
Poliovirus is primarily transmitted through the fecal-oral route, which means it can spread through contaminated food or water. It can also spread through direct contact with an infected person. While many infections result in no symptoms, a small percentage of cases can lead to more severe neurological effects, particularly in children.
Vaccination has been the key strategy in controlling and nearly eradicating polio worldwide. The two main types of vaccines used are:
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Inactivated poliovirus vaccine (IPV) - This vaccine contains killed virus and is administered by injection. It is used in many countries as part of routine immunization.
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Oral poliovirus vaccine (OPV) - This vaccine contains weakened live virus and is administered orally. It has been instrumental in mass immunization campaigns, particularly in areas with polio outbreaks.
Efforts by the Global Polio Eradication Initiative have significantly reduced the incidence of polio, but some regions still experience outbreaks, and ongoing vaccination efforts are critical to fully eradicate the disease.