Polio is caused by the poliovirus. This virus destroys nerve cells in the spinal cord which casues muscle waiting and paralysis. It is transmitted through contaminated food or water or contact with an infected person.
- polio mainly affects children 5 years old or younger
- In most countries, the global effort has expanded capacities to tackle other infectious diseases by building effective surveillance and immunization systems
- 1 in 200 infections leads to irreversible paralysis
- Of the 3 strains of wild poliovirus (type 1, type 2, and type 3), wild poliovirus type 2 was eradicated in 1999 and case numbers of wild poliovirus type 3 are down to the lowest-ever levels with the no cases reported since a case reported by Nigeria in November 2012
Polio cases have decreased by 99% since 1988.
In 1952, there were 3,145 reported deaths due to polio.
There are 2 types of Polio vaccines
- Inactivated polio vaccine (IPV): consists of inactivated (killed) poliovirus strains of all three poliovirus types. it also produces antibodies in the blood to all three types of poliovirus. In the event of infection, these antibodies prevent the spread of the virus to the central nervous system and protect against paralysis.
- Oral polio vaccine (OPV): The attenuated poliovirus contained in OPV are able to replicate effectively in the intestine, but around 10,000 times less able to enter the central nervous system than the wild virus. This enables individuals to mount an immune response against the virus.