Scientists believe they have found a drug which could eventually be used to combat the viruses that cause colds.They say they have developed a compound which could prevent the viruses infecting humans.The researchers, from Oxford, Leeds, Beijing, and Innsbruck have found a compound which targets the virus responsible for hand, foot and mouth disease – a condition that causes epidemics in children in Asia.This, they say, is also an important breakthrough in the hunt for a cure for the common cold.This is because the drug could also be effective against viruses similar to those that cause hand, foot and mouth disease – including the common cold virus.Professor Dave Stuart, Director of the Division of Structural Biology (STRUBI) in the Nuffield Department of Medicine at the University of Oxford, said: ‘By targeting a structural feature also found in related viruses, it should be possible to devise similar therapeutics to target them. ‘Within the field, I am aware of one company that is already making progress in targeting the major common cold virus. Our work is still at an early stage, but we are working with academic groups in China to take the inhibitor forward.’The new drug treatment, which so far has been tested only in isolated cells, was created using pionerring techniques. The researchers focused on finding a drug that could target the structure of the virus.Firstly, they had to understand the structure of the virus. Secondly, they determined how that structure related to the functioning of the pathogen. Finally, they developed a means of interacting with that structure to disable the virus.The structure of EV71 – the virus that causes hand, foot and mouth disease - was first solved in 2012.After this, scientists used a giant microscope to determine how the virus changes shape to enter human cells.  Called Diamond Light Source, this giant microscope allows scientists to glimpse the shape of virus and bacteria components at atomic-level and get some insight into how they function.The virus has an outer shell which, once inside a host cell, breaks apart releasing the viral RNA into the cell. The team discovered a very potent molecule which disables the mechanism by which the viral shell breaks open, thus stopping the virus in its tracks by making it unable to infect the person.When they determined the virus structure in 2012, the team saw a small pocket inside the virus where a drug might fit.They have now developed a potential drug molecule that can sit inside this pocket, where it locks the virus rigid, preventing it breaking open and releasing its RNA.However, this research is still in its early stages, and there is a long way to go before the drug treatment is available on the market. The researchers say they also have to be cautious as viruses evolve exceptionally fast, and it may be that EV71 mutates to overcome the inhibitor. However, the early signs are promising, and now that the methodology exists, scientists may be able to develop the inhibitor to become resistant to mutations. The research was published in the journal Nature Structural and Molecular Biology.(dailymail.co.uk)ANN.Az