Immunisation is one of the biggest health successes of the last century.
Some diseases that are caused by viruses cannot be cured with antibiotics. The only way to control them is by immunisation.
With continued immunisation programmes, such diseases may no longer be a threat.
There have already been some successful examples of immunisation bringing some diseases under control. Both smallpox (external link) and polio (external link), which were once common in the UK, are no longer a threat.
The World Health Organization declared smallpox wiped out in December 1979 thanks to a focused effort to immunise against the disease across the world. It declared Europe free from polio in 2002.