Scientists have developed a "one -size-fits-all" jab to cure allergies, including hay fever and asthma, which they claim would be available in the market in just four years' time.

A team, which developed the jab, claims the injection would be the "holy grail" of vaccines as a single dose would protect against a number of allergies and ward off reactions to cat fur, dust and peanuts.

Dr. Wolfgang Renner, from Cytos Biotechnology, which developed the jab, said, "We think it is a one-size-fits-all mechanism. We are very excited about it."

Recent trials showed the jab was as effective as taking steroids when used to fight asthma. It found that when comparing 63 asthma sufferers who were given the jab or a fake drug over two or three months, the new vaccine slashed asthma attacks by a third, the 'Daily Express' reported.

In another trial, the drug - CYT003-QbG10 - was given as a jab once a week for six weeks. The scientists found this cut runny noses and weepy eyes - symptoms caused by an allergic reaction to house dust mites and reliance on other medicines -- by 39 per cent.

The jab also boosted quality of life by 42 per cent, according to Dr. Renner who said larger trials could start next year and the vaccine could be on sale within four years.

Experts have welcomed the jab.

An Allergy UK spokesman said, "It does sound a very promising treatment, giving hope for those with severe asthma/allergy symptoms for whom the usual treatments aren't enough but there is still a long way to go before it will be available."

Leanne Metcalfe, director of research for Asthma UK, added, "We are excited about the potential of this vaccine to make a real difference."