In the first six months of this year, cases of measles almost doubled on the same period in 1993 - from about 4,000 to 8,706 - reversing a trend that had seen the disease fall to a record low. More cases are being reported in older children and teenagers, who tend to suffer more serious forms of the illness than younger children.
Dr Kenneth Calman, chief medical officer, said yesterday that there was strong evidence that unless a mass immunisation campaign is carried out among 5- to 16- year-olds 'we will experience the largest measles epidemic since the early 1980s.'
Although 93 per cent of pre-school children are protected from the disease by the MMR vaccine (measles, mumps and rubella) introduced in 1988, up to 1.2 million (14 per cent) of secondary school children remain at risk. Dr Calman said there was no epidemic at present but data collected by the Communicable Disease Surveillance Centre showed that 'accumulated groups of susceptible individuals are now sufficiently large to sustain a significant measles epidemic.'
Between 100,000 and 200,000 children would be affected, two-thirds of them of secondary school age.
About 50 deaths could be expected with many children at risk of serious side-effects of measles such as pneumonia, blindness, deafness, and brain damage. Last year there were 9,000 cases of measles and there have been no childhood deaths in England and Wales since 1989.
Dr Calman said: 'We are determined to take every necessary step to continue to protect children at risk and to prevent a 1995 measles epidemic with all the suffering it could bring and some deaths.' He advised parents of pre-school children who will not be included in the programme and who have not been vaccinated yet as part of the MMR childhood programme, to see their GP as soon as possible.
The pounds 20m vaccination programme, which is school- based and will begin in November, will also protect children and teenagers from rubella. This infection can cause serious foetal defects if a pregnant woman contracts it, and vaccination of teenage girls at school has reduced susceptibility to between 1 and 2 per cent. However, among young men the susceptibility is 20 per cent and they present a source of infection for young women.
Ten million units of the vaccine are now in production and will be ready in October. It has been widely used for 20 years, and has fewer side effects in older children.
Eligible children who have already had measles or have been immunised will have their immunity boosted.
Measles is an acute infectious viral disease which is rare in children under six months and adults. It is accompanied by a characteristic rash and fever. In 1988, the year that the childhood MMR vaccine was launched, the number of cases stood at 86,001. Before the first vaccine became available in 1968 there were between 160,000 and 800,000 cases a year.