Friday, June 26, 1998 Published at 01:14 GMT 02:14 UK
Drop in MMR jabs blamed on media scare
The first MMR jab is given at around 15 months
Publicity about the alleged dangers of the combined measles, mumps and rubella (MMR) vaccine may have damaged the immunisation programme in Wales.
Researchers have studied the percentage of children taken for an MMR jab in the principality and found a drop in the numbers coming forward.
Fears about the safety of the jab were raised in February following the publication of a study by doctors at the Royal Free Hospital in London. It suggested a link between autism and a newly identified bowel disease found in some children after having the combined vaccine.
The study was later contradicted by further research conducted in Finland. But public health officials feared the publicity surrounding the scare would harm efforts to persuade parents to take their children for a jab.
Public health concern
This fear is supported by preliminary data collected in Wales by the Public Health Laboratory Service.
The researchers, led by Dr Daniel Thomas and Dr Roland Salmon, looked at the percentage uptake of MMR in Welsh children aged 24 to 26 months and 15 to 17 months by March 31, 1998. This was compared with similar figures for the same age groups in 1994, 1995, 1996 and 1997.
The data showed a general decline in the numbers coming forward for immunisation in Wales since 1995. For children aged 15 to 17 months, the average percentage figure between March 1997 and March 1998 fell by more than 4% from 77.3% to 73.2%.
The controversial London study hit the headlines just a month before the end of this period in February.
Simon Barber, spokesman for the Public Health Laboratory Service is cautious about linking the two.
"It's certainly one possible explanation that the media coverage following on from the London study may well have affected parents' confidence in the vaccination of MMR," he says. "It's an early warning to see how the trends develop over time."
The decrease in uptake was most marked in one Welsh health authority area in which MMR vaccination had received sustained adverse publicity in the local media. Here, uptake fell from 83.1% in 1997 to 69.6% in 1998.
MMR uptake for children aged 24 to 26 months was consistently higher and showed a less marked decline. By the end of March 1998, 89.1% of children in this age group were immunised.
The researchers, writing in The Lancet, calculate that MMR uptake by the age of two years in the group now aged 15 to 17 months would be about 85%. This figure is highly significant. Models of the diseases suggest immunity of 94-96% is necessary to eliminate measles.
"The concern is that if there is a continued fall off in vaccine uptake you will have these diseases returning and all the health problems associated with them," says Simon Barber.
The MMR vaccine is given in two doses, the first around 15 months. Most children have no side effects from the MMR vaccine, but a small percentage develop a fever. Some develop a measles-like rash, swelling of the lymph glands, and mild pain in the joints.