Sunday, 14 January, 2001, 14:26 GMT
The controversy over the measles mumps and rubella vaccine shows no sign of abating. BBC News Online talks to two mothers on opposite sides of the argument.
Vivian McKelvey, believes her son Alec developed autism and bowel disease from the MMR jab:
Vivian McKelvey can look back at videos of her son Alec, now eight, who was a normal, happy child developing normally.
She said: "He was very social before the jab and in excellent health.
"Afterwards, his personality changed and he was frequently ill."
Alec is now doing well, and attends a normal school.
Mrs McKelvey said: " He is now getting treatment for his bowel disease and follows a special diet. We are doing the best we can but I wish he had never had that vaccine."
Alec had the jab when he was 12 months old. Six months later, his parents noticed changes - he was suffering from diarrhoea and having tantrums - which mother says were obviously worse than healthy children went through.
Mrs McKelvey said: "It took six months to become obvious he was becoming brain damaged."
He was eventually diagnosed with colitis, a bowel disease, and as autistic.
His mother, who is a trustee of a charity called Allergy Induced Autism, which has 2,000 members, believes the MMR caused her son's bowel disease, which then led to brain damage.
"I firmly believe it's connected to the measles virus. I believe the jabs should be given separately."
She is calling for more independent research into the effects of the combined vaccine.
She added: "My daughter, who is six, did not have the MMR vaccine. She had measles and was ill for two weeks. Since then, she has been fine."
Jane Mulholland says she would do anything she could to prevent other children from contracting rubella as son Roger did:
Roger Mulholland, 14, has congenital rubella syndrome.
His mother Jane contracted the disease when she was pregnant, after having what she believes was an ineffective jab before the mass immunisation programme started.
When Roger was born, he was a small baby, covered in blood blisters.
Within a day it was confirmed that he was blind and had severe brain damage.
He was later found to have four separate heart defects and to be completely deaf.
He has endured years of surgery, and now attends the Royal School for the Deaf, where he has to have one-to-one teaching.
Jane Mulholland said: "We do ordinary things, but we have to have the courage to do things differently to everyone else."
Roger still has to have operations - and the whole family is affected by his illness.
"It's always there. Once you have brain damage, it's there for ever. It doesn't go away for any of us."
Of the MMR jab, she said: "I would do anything to reduce, as much as possible, the known risk - the absolutely proven risk - of the mental and physical disabilities that the rubella virus definitely causes."