About 3 per cent of babies have a peanut allergy that mostly persists throughout their life, and of all food allergies, a peanut allergy is the most likely to cause a severe anaphylactic reaction.

But researchers from the Murdoch Children's Research Institute say they might have found a treatment which could be available within five years.

In a world first study reported last year, the researchers gave 28 children a daily combination of peanut protein and a high dose of probiotics (the equivalent of those found in two kilograms of yoghurt) over the course of 18 months.

When they stopped treatment and fed the children peanuts about four weeks later, they found 80 per cent of children could tolerate the equivalent of up to 20 peanuts. The children aged one to 10 went home to continue regularly eating peanuts.

Among 28 children who received a placebo, one of them (4 per cent) could tolerate peanuts at the end of the study. The researchers said this was expected because about 20 per cent of children with a peanut allergy recover from it naturally over time.

The study, published in the Journal of Allergy and Clinical Immunology, meant children were exposed to allergic reactions throughout the study. The majority experienced mild to moderate symptoms along the way, such as hives and welts. Up to 10 per cent experienced a severe allergic reaction. There were no deaths.

Lead author of the study Professor Mimi Tang said most of the children who were eating peanuts at the end of the trial were still eating peanuts years later - a behaviour thought to help maintain tolerance. Her team are due to publish a study on the longer term effects for those children soon.

However, Professor Tang said it was possible these children would become allergic again in future, because other studies of people whose allergies appeared to have been treated went on to experience allergic reactions again.

The team are now hoping to see similar results in a study of more than 200 children across Melbourne, Adelaide and Perth. Recruitment is currently under way with only about 40 children signed up so far.

Professor Tang said the group had received funding from the National Health and Medical Research Council for the study and capital investment firm OneVentures to try to speed up its progress. If the study went well, she said the vaccine, which effectively reprograms the immune system's response to peanuts, could be available to purchase in 2021 at the earliest.

Other treatments for peanut allergies are in the late stages of development and could be approved for sale by the US drug regulator soon. Professor Tang said one was a peanut patch that could be applied to skin every day, and another was a medicine based on peanut protein alone.

However, she said research showed these led to desensitisation only, not tolerance. Desensitisation means you have to continue taking the treatment whereas tolerance means you can eat peanuts without the treatment.

The study reported last year was funded by the Food Allergy and Anaphylaxis Network, the Murdoch Childrens Research Institute, Perpetual Philanthropy, the CASS Foundation, the Financial Markets Foundation for Children and the National Health and Medical Research Council Australia. Nestlè Health Science were also involved.

People interested in the Murdoch Children's Research Institute study can email: peanut.study@mcri.edu.au