The polio vaccine protects against polio, a very contagious viral infection that affects the spinal cord and brain. Polio can cause permanent muscle weakness, paralysis, and sometimes death.
Extensive vaccination has almost eradicated polio worldwide. A global polio eradication program is under way, but cases of wild poliovirus infection still occur in Pakistan and Afghanistan and were last reported in Nigeria in 2018.
Worldwide, two formulations are available:
Inactivated polio vaccine: Contains killed virus and is injected into a muscle or under the skin
Oral polio vaccine: Contains live, weakened (attenuated) virus and is taken by mouth
Inactivated polio vaccine is the only polio vaccine that has been given in the United States since 2000.
The inactivated polio vaccine may be combined with other vaccines, such as the diphtheria, tetanus, and pertussis vaccine and sometimes hepatitis B vaccine or Haemophilus influenzae vaccine.
In addition to wild-type poliovirus, very rarely (about 1 in 2.4 million doses), the live poliovirus in the oral vaccine mutates. The mutated vaccine virus can spread from the person who received the vaccine to unvaccinated people, continuing to mutate and potentially causing polio. In some countries, the mutated vaccine virus from the oral vaccine was virtually the only cause of polio, so most of these countries (including the United States) stopped using that formulation.
In the United States, a case of vaccine-derived polio was identified in an unvaccinated person who acquired it in New York State in July 2022. No additional cases have been identified in the United States, but wastewater surveillance has detected the virus in samples across several NY counties, indicating local transmission (see also New York State Department of Health: Wastewater Surveillance).
For more information, see the Centers for Disease Control and Prevention's (CDC) Polio vaccine information statement.
(See also Overview of Immunization.)
Administration of Polio Vaccine
Vaccination against polio is part of the routine vaccination schedule recommended for children (see CDC: Child and Adolescent Immunization Schedule by Age). The polio vaccine is given in four doses: at age 2 months, 4 months, 6 to 18 months, and 4 to 6 years.
Polio is extremely rare in the United States. The risk of exposure may be increased if people travel to an area where polio is common (see CDC: Travelers' Health), work in a laboratory with materials that may contain the virus, or provide medical care to people who have polio.
If adults are unvaccinated or incompletely vaccinated and are at increased risk of exposure to poliovirus, they should receive and complete the polio vaccination series. Other adults who are unvaccinated or incompletely vaccinated should talk with their doctor to understand their risk of polio and whether they should receive polio vaccination. Adults who completed their polio vaccination but who are at increased risk of exposure to poliovirus may receive one lifetime booster.
New York residents in areas with repeated poliovirus detection may be at higher risk of infection and should follow updated vaccination recommendations from the New York State Department of Health (see New York State Department of Health: Polio Vaccine).
If people have a temporary illness, doctors usually wait to give the vaccine until the illness resolves (see also CDC: Who Should NOT Get Vaccinated With These Vaccines?).
Side Effects of Polio Vaccine
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
Centers for Disease Control and Prevention (CDC): Polio vaccine information statement
CDC: Travelers' Health: Information about travel health notices and what vaccines to get depending on destination
European Centre for Disease Prevention and Control (ECDC): Poliomyelitis: Recommended vaccinations
