A million children who missed out on getting the MMR vaccine in England are being targeted as part of a 'catch-up' campaign to raise the level of protection against measles following an outbreak in Wales. 2013 is set to be the worst year for measles outbreaks in 20 years.
What is measles?
Measles is a "highly infectious" viral illness. It can lead to serious complications and can even be fatal. Measles is caused by infection with the rubeola virus.
How can people catch it?
The virus spreads when infected people cough and sneeze - it is contained in the tiny droplets. People become infected by breathing in the droplets or by touching a surface that has been contaminated with such droplets and then touching their noses or mouths.
Who is most likely to get it?
Measles is most common in children aged between one and four but anyone who has not had it before or been vaccinated can get it.
What are the symptoms?
Cold like symptoms
Sensitivity to light
Greyish white spots in the mouth and throat
After a few days a red-brown spotty rash will appear - the rash usually starts behind the ears, spreads round the neck and head then to the rest of the body.
What are the complications?
Measles is "extremely unpleasant". Common complications of the infection are diarrhoea, vomiting, eye infections and laryngitis. It can also lead to complications including meningitis and pneumonia. Some people can die from the illness.
What is the treatment?
There is no specific treatment for the infection and the body's immune system should fight off the illness in a couple of weeks. But in severe cases hospital treatment may be needed.
How can it be prevented?
The most effective way of preventing measles is the measles, mumps and rubella (MMR) vaccine. The first MMR vaccination should be given when a child is around 13 months old, followed by a booster vaccination before the child starts school.
Why are there fears about the vaccine?
Shamed doctor Andrew Wakefield was struck off the medical register for his discredited research, which claimed to find a link between autism and the MMR vaccine. The study, published in 1998, caused a global scare and uptake levels of the vaccination fell significantly in the years after its publication.
Measles is a 'notifiable disease' - what does that mean?
Any doctor that spots a notifiable disease must inform their local health authority - this means officials can track the infection and try to stop it spreading.