The parents of an 18-month-old boy who died 10 days after having his MMR jab lost a “David and Goliath” battle against the establishment, a vaccines pressure group said last night.

Jabs (Justice Awareness and Basic Support), which supports “vaccine-damaged” children, claimed baby George Fisher’s inquest found he died of natural causes because only “inadequate” data about the drug was available.

George was discovered dead in his cot in Cheltenham, Gloucestershire, on January 19 2006 by his mother, Sarah Fisher, hours after he was heard “chatting away on the baby monitor”.

Mrs Fisher, 42, and husband Christopher, 43, still believe the vaccine is “implicated” in their son’s death as its temperature-raising effects on children who have previously suffered a fit, as George had, were not explained to them.

Yesterday Gloucestershire coroner Alan Crickmore decided, after listening to a series of expert witnesses, that George’s symptoms had emerged too soon after the Measles, Mumps and Rubella (MMR) jab to be related to it.

Although George had a 2% chance of suffering a convulsion after the jab, those were not known to be fatal and there was no evidence he had even had a second fit.

Instead county coroner Alan Crickmore found he died from a rare condition known as Sudden Unexpected Death in Childhood, due to an unascertained disease.

JABS spokeswoman Jackie Fletcher said after the verdict in Gloucester that the tests carried out before MMR was licensed were too limited and that surveillance of the drug’s safety was currently based on only a ’tiny’ sample.

She said: “The process was compromised because it was a David versus Goliath situation and David didn’t have a strong slingshot. The legal representation for the family was unable to match that of the vaccine manufacturer’s resources.

“I am surprised the DoH said there was no evidence of a seizure being linked with a child’s death following MMR as our Government’s Vaccine Damage Payment Unit has made a number of payments to families whose children have died following MMR including after seizures. Measles virus was found in the child’s lungs.

“The pre-licence trials were too short in duration and too few in numbers to show up the ’rare’ events. The vaccine surveillance system is inadequate in that only a tiny proportion of adverse reactions are put forward for investigation therefore making the safety data equally inadequate on which the DoH evidence was based.”

Department of Health guidelines say the jab should be given “with caution” but does not ban child sufferers of febrile convulsions – fever fits – from taking it and recommends temperature monitoring.

Fighting back tears, Mrs Fisher, a hotel receptionist standing outside court with her husband, a pipe-fitter, said: “I think it’s so wrong to put the death of a healthy little boy down to natural causes. There’s nothing natural about an 18-month-old boy dying of nothing, because that’s what it was – nothing.

“This has devastated our family all over again. Three years of work and reports and it’s just natural causes? I’ll never, ever understand that word.”

In a 13-page verdict the coroner said that George’s “loving and experienced” parents were not to blame in any way for the tragedy.

He ruled that just because the MMR jab and the death happened closely in time, there was nothing to show the jab on January 9 2006 caused the death 10 days later.

Mr Crickmore was convinced by the evidence of Infant Health Professor Peter Fleming, of Bristol University, who put forward Sudden Unexpected Death in Childhood as the cause of death.

Prof Fleming could not find a link to the MMR vaccine despite looking “extremely hard” because of George’s parents’ concerns.

Earlier in the three-day inquest, the coroner heard that George was born at a healthy 8lb 10oz, and came through his routine injections with no side-effects.

GP Annette Bugaighis confirmed that, four months before his jab, on September 25 2005, George fell ill after returning from a holiday in Spain.

After suffering a fit at the Overton Park surgery he was rushed to hospital, where it was found he had suffered febrile convulsion – a fit caused by a fever.

Both Dr Bugaighis and consultant paediatrician Alan Day, of Cheltenham General Hospital, agreed that George was safe to be given the vaccine on January 9 2006 - adding that he should be monitored for possible raised temperature.

In evidence, Mrs Fisher said her son was a “healthy and robust” child who had breast-fed for 11 months – longer than her other three children.

After his febrile illness he was given antibiotics and on the Wednesday before he died was “running around, playing football with his father”.

The night before he died he was “chatting away on the baby monitor”, she added.

She said: “He took his bottle of water and I put the quilt over him, stroked his head and said goodnight. I went to bed, heard him drink his water, then throw the bottle on the floor. I heard him shuffling around.”

At 8am his sister, Meg, who was sharing a room with him, called out to her.

She added: “I was surprised he was not awake. I tried to wake him but it was clear he was dead because of his colour and he was cold.”

Mr Fisher said: “If we had (been given a Patient Information Leaflet), we would have gone to hospital much quicker because of the information in that list. We would have been much more concerned than we actually were.”

The coroner said in his judgment that whether or not the parents were given advice on monitoring him had not affected the outcome, as they had done so anyway, as experienced parents.

Professor Elizabeth Miller, an immunisation expert for the Health Protection Agency said: “Fatal outcomes associated with MMR vaccination as a result of febrile convulsion have not, to my knowledge, been reported.”