Hopes of developing a food allergy vaccine have been raised after successful trials of a vaccine on dogs.
One in 70 children are allergic to peanuts in England
Researchers found the vaccine made the dogs up to 100 times less susceptible to developing allergic reactions.
The vaccine, tested by the Stanford University School of Medicine in the US, provided protection for three months.
It is the first time an allergy vaccine of any kind has been tested on anything other than mice.
Some 15 million people in England - 30% of adults and 40% of children - have an allergy and the figure has been rising for the last 20 years.
Food allergies, in particular, have become more common.
Until 1990, allergy to peanuts was rare, by 1996 one in 200 children were allergic and by 2002 this had rise to one in 70.
Nine dogs - four with peanut allergies and five with both milk and wheat allergies - were given the vaccine during the study.
Ten weeks after the dogs were vaccinated, significantly greater amounts of food had to be used to generate an allergic reaction.
The toleration level for the peanut-allergic dogs went from one on average to 37.
One dog, with a toleration level of half a peanut, ate 57 peanuts without a reaction - a 100-fold increase.
The milk-allergic dogs exhibited a 100% reduction in vomiting and a 60% reduction in diarrhoea.
The vaccine was developed by mixing Listeria, a common food-borne bacteria, with peanuts, milk and wheat.
At the moment, the only medications available for allergies treat the reactions.
Lead researcher Professor Dale Umetsu said it was a potentially important breakthrough.
"Food allergy is a problem for which there is no good treatment. Developing a cure for this will help millions of people and save lives."
However, he acknowledged it would be a long time before a human vaccine was developed.
Muriel Simmons, of Allergy UK, was also cautious.
"It is good news for dogs, who are particularly prone to wheat and milk allergies.
"But I would not want people to get their hopes up too much, animal studies do not always translate that well to humans."
David Reading, director of the Anaphylaxis Campaign, added: "It is a step forward but I think it will be years before human trials take place.
"Historically, allergies have not been researched enough but over the past few years that has changed. It is a long process."