It contains the live, but weakened, poliovirus and because OPV uses the live virus, it has the potential to cause infection in individuals with weak immune defenses (both in the person who receives the vaccine and in close contacts).
A vaccine takes advantage of the fact that infection with polio leads to an immune reaction, which will give the person permanent, lifelong immunity from reinfection with the form of poliovirus for which the person was vaccinated.
Poliovirus can be spread by direct exposure to an infected individual, and more rarely, by eating foods contaminated with waste products from the intestines (feces) and/or droplets of moisture (saliva) from an infected person.
When poliovirus invades the brainstem (the stalk of brain which connects the two cerebral hemispheres with the spinal cord, called bulbar polio), a person may begin to have trouble breathing and swallowing.
If an individual is infected with the wild-type poliovirus, the virus can multiply in the intestines and be shed in stools, ultimately heightening the risk of viral circulation within the community.
This immunization contains no live virus, just the components of the virus that provoke the recipient's immune system to react as if the recipient were actually infected with the poliovirus.
Polio vaccine (IPV, or inactivated poliovirus vaccine)-This is usually given in a series of five vaccines, at ages two months, four months, six to 18 months, and four to six years.
The inactivated poliovirus vaccine is injected into a muscle or under the skin and is usually given by a health care professional in a hospital, clinic, or provider's office.
Children receiving the inactivated poliovirus vaccine should be carefully observed for 24-72 hours after receiving the injection.
In 1908, the poliovirus was identified as the cause.