What is Polio?
Polio is an infectious disease caused by one of three types of Polio virus. It enters your body through your nose or mouth and develops in your throat and intestines. The Polio virus may go on to invade your central nervous system, destroying or damaging the nerve cells (motor neurons) that control your muscles.
Can Polio be prevented?
Polio can be prevented by vaccination.
Do vaccinations really make a difference?
Yes they do. Since the programme was introduced into the UK in the early 1960s notifications of Polio have dropped from over 6,000 in 1955 to nil today.
The risk of Polio infection has been eliminated in most, but not all countries.
However, the Polio virus could be imported into a Polio-free country with the risk of it spreading rapidly amongst non-immunised people.
Since October 2004, people in the UK have been vaccinated using an inactivated Polio vaccine (IPV) given by injection into a muscle. This replaced the routine use of oral Polio vaccine in the UK.
The IPV vaccine uses inactive (not live) Polio virus and does not cause Polio. Polio vaccine, given multiple times as per advice, almost always protects for life.
For further information: World Health Organization
For further vaccine information: NHS Choices
What happens to your body when you have Polio?
The Polio illness can affect you in one of three ways:
Approximately 95% of people have minor flu-like symptoms, such as feeling sick or being sick, a high temperature, sore throat and headache. They may not realise they have Polio.
In around 5% of people, the virus gets into their nervous system. For most people this will cause symptoms such as a high temperature, stiff neck, back and muscle pain and headache. This is known as non-paralytic Polio.
In around 1 – 2% of people affected, the Polio virus invades the motor neurons, leading to weakness, paralysis, muscle cramps and muscle pain. This is known as paralytic Polio. Sometimes the Polio virus affects the brain stem, causing symptoms like breathing, swallowing or cardiovascular problems and facial weakness. This is known as bulbar Polio.
Polio is not thought to affect the sensory nerves, so people can still feel pain.
Polio does not affect hearing or eyesight.
What happens to your body as you recover from Polio?
To begin with, some of the nerve cells that control your muscles will die or be left damaged.
Damage to nerve cells may be widely distributed throughout the body so may not cause any noticeable weakness.
Muscles can often still be used and appear normal when tests are run, even when perhaps 50% of the nerve cells are lost or damaged. This may be because the remaining muscles are working harder to compensate.
About half of the damaged nerve cells recover within the first month. During the following months or years, muscle strength may improve as the number of nerve fibres increases and muscle fibres grow larger.