BBC Wales has learned that many people are diverting funds to pay for the £240-a-course injections instead of allowing their children to receive the combined MMR jab - because of fears of side-effects.

Amanda and Terence Reynolds were among many couples who attended a privately-run clinic in Swansea, south Wales, at the weekend.

Their son Tudor, aged 16 months, is receiving the single injection because they believe their other son, Morgan, now seven, was badly-affected by the traditional triple vaccination.

Despite the absence of hard evidence linking the MMR vaccine to autism, they are convinced it affected Morgan's development.

"I just can't risk having the MMR and having problems," Mrs Reynolds said.

"Paying for it wasn't an issue - if we have to do without something, we will."

The Reynolds decided on the single-dose medication after Morgan experienced delays in his development which coincided with the triple jab.

"He didn't speak until he was four," said Mrs Reynolds, a nurse.

"His head would be banging on the walls, and he couldn't communicate or interact with other children. They actually queried whether it was a kind of autism."

His parents refused the booster jab, and were adamant that their next child would not receive the same treatment.

"Side effects"

Janet and Hywel James, from Carmarthen, have made the same decision in respect of their daughters Nia, 17 months, and Manon, seven weeks.

"We have decided to have the vaccinations singly because I've got a friend who had a little boy affected since the MMR vaccine and has autism - so I've seen the side effects and how it has affected the family," she said.

Mr James said the £80-a-shot treatments were well worth paying for.

"If you've got more than one child, it adds up to a hell of a lot, but if it means the child is going to be right for life, it's nothing," he said.

Drop in demand

Meanwhile, the UK's only supplier of a single dose rubella vaccine is to stop making it.

Pharmaceutical company GlaxoSmithKline said it would stop producing rubella vaccines at its factory in Belgium.

It cited a worldwide drop in demand for single vaccines with the increasing take-up rate of the triple measles, mumps and rubella jab.

Campaigners believe the move will put families under more pressure to use the triple jab, as stocks of single vaccines diminish.

"Right way"

GlaxoSmithKline said it would continue to supply the NHS with rubella vaccines until its contract ran out in January 2004, but said the stocks it had left would be "made available to non-immune women of child-bearing age".

"Ninety countries worldwide are now using the MMR vaccine and the scientific community believe this is the right way to vaccinate," said a spokesman.

"No country is recommending the use of single vaccines over MMR."

Difficult

A Department of Health spokesman said single rubella vaccines would continue to be provided to women of child-bearing age - but not to children - on the NHS.

"As far as we're concerned, we have our own supplies of the rubella vaccine. We are currently tendering for more for next year but that is not going to be with GlaxoSmithKline."

Statistics from the Public Health Laboratory Service, published last month, show just 70% of 16 month-olds received MMR vaccinations in March - down 6% since the end of last year and well below the government's target of 95%.