Colds are known to be a major trigger of asthma attacks and asthmatics are far more likely to suffer a severe attack during a cold and even end up being hospitalised.

According to researchers in the UK the reason why colds make people with asthma more likely to have a severe and potentially fatal attack is because asthmatics only produce half the number of anti-viral proteins when they have a cold that non-asthmatics do.

As many as 1,500 sufferers die every year in the UK and the scientific breakthrough could mean asthma sufferers could be protected from a severe or potentially fatal attack.

The team from Imperial College and the Medical Research Council Centre in Allergic Mechanisms of Asthma, tested lung cells from people with and without asthma.

They say that people with asthma are particularly susceptible to rhinoviruses, a major cause of severe asthma attacks, and asthmatics have particularly low levels of a type of a protein with antiviral properties generated by the immune system.

The proteins act as the lung cells’ first line of defence and the lower the level of the antiviral protein, the more severe the asthma attack.

The team say boosting levels of these proteins could protect people with asthma from having an attack because of a cold.

The team, led by Professor Sebastian Johnston suggest their discovery could lead to a new way of treating or preventing asthma attacks as inhalers could be used to deliver extra interferon directly to the lungs to help the immune system fight viral infections.

Such treatment could be given either when the first symptoms of a cold appear, or even throughout winter as a preventative measure.

Professor Johnston says the team are now carrying out trials to look at ways of treating patients with interferons, and trying to discover why they have too few.

The research was funded by Asthma UK and the British Lung Foundation and is published in the journal Nature Medicine.