The Yendles from Tonteg, near Pontypridd, say their daughter Sara was left with acute epilepsy and other conditions after receiving her DTP jab 12 years ago.

Phil Yendle: Concerns

DTP - which protects against diptheria, tetanus and whooping cough - has been given to millions of children and GlaxoSmithKlein deny any health side effects.

But the Yendles are one of 120 families taking action against the company.

Sara has had thousands of epileptic fits over the past 12 years since receiving her second routine DTP jab as a baby.

Her father Phil has been told her condition will never improve.

"She is 12-years of age and she is basically like a toddler and from what we have been told, she will always be like that," he said.

The family are among 120 cases

"She cannot read and write and she becomes incontinent and Sara has balance and coordination problems."

Sara has already received compensation under the government's Vaccine Damages Scheme, because of the extent of her brain damage.

But now solicitors are looking at a class action against Glaxo Smith Klein and they are examining new medical evidence.

Manufacturers said a previous test case in 1998 found no proof of any links to brain damage.

Last year, scientists suggested the DTP vaccine could guard against cot death, following during a study which actually set out to investigate whether there are links to Sudden Infant Death Syndrome (SITS).

Immunisation may offer some protection against the threat of cot death, a scientific study has suggested.

Cot death study

The fears over the role played by the DTP jab arose because many cot deaths happen around the time that the injection is administered.

Scientists from Bristol University looked at more than 470,000 cot death cases from between 1993 and 1996, checking to see if the victims had been immunised or not.

They found that only half the babies who had died from cot death had taken part in immunisation. Two-thirds of the live babies had taken part.