Parents with young children in Liverpool are being urged to get them vaccinated against measles at special weekend immunisation clinics.
Liverpool Primary Care Trust (PCT) is holding sessions on Saturday and Sunday where any child from 18 months to five years old can get the combined MMR jab.
It is encouraging parents to take up the offer to reduce the risk of a measles outbreak in the city.
The sessions are being held at Tarron House in Aintree.
Dr Emer Coffey, consultant in public health for Liverpool, said: "Although many parents have already responded to our requests to ensure their children are vaccinated, we continue to be very worried about the risk of a measles outbreak.
"Thousands of Liverpool children have missed out on their MMR vaccinations over the past 10 years, which has contributed to a 13-year high in the number of cases across the country, and we are worried about he risk of a large outbreak here in Liverpool."
Children aged from five to 18 who have missed any of their vaccinations should contact their GP, the PCT said.
Although most children recover from measles, it can be a serious illness.
One in 10 cases requires hospital treatment and the disease can lead to pneumonia, brain damage and even death. THE BBC