Since immunisation was introduced in Europe after the mid 1950s, the number of polio cases dropped tremendously.

There are two ways of immunisation:

• It can be done by an injection into the muscle with inactivated polio virus (IPV). This is called the Salk vaccine.
• The other way is with oral (administered by the mouth) polio vaccine (OPV), known as the Sabin vaccine. This is made from weakened polio viruses.

The vaccinations must be given multiple times as per advice.