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, according to a vaccines pressure group.

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 her husband Christopher, 43, still believe the vaccine is "implicated" in their son's death because its temperature-raising effects on children who have previously suffered a fit, as George had, were not explained to them.

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.

He found instead that George had died from a rare condition known as Sudden Unexpected Death in Childhood, due to an unascertained disease.

Jabs spokeswoman Jackie Fletcher 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."