BBC Panorama has been allowed inside a UK coronavirus drugs trial for the first time.
The SNG-001 drug, being developed by Synairgen, prepares the body for a viral attack by stimulating the immune response in the lungs of asthma and chronic lung disease patients.
It is hoped the treatment will help coronavirus patients and prevent the most severe cases from requiring intensive care and ventilators.
Panorama has spoken to those involved in a trial at University Hospital Southampton.
Richard Marsden, the CEO of Synairgen, said: "Our drug is a special formulation of interferon beta that we deliver directly to the airways when the virus is there.
"What we've shown in our research is that older people, and people with some chronic conditions, have a poor interferon beta response when there's a virus present. Coronavirus does the same thing."
SNG-001 uses interferon beta - a protein produced by the body to tackle viruses.
Southampton University's Professor Tom Wilkinson, who is leading the trial, said: "In an ideal world we would see a significant improvement in the health of the patients receiving the drug, a reduction in those requiring intensive care and ventilation.
"But it is early days to understand that and we will know more when we have the results."
The results of the trial are expected by the end of June.
Synairgen is already talking to suppliers about producing the drug as soon as the trial has finished.
It is aiming to distribute it later this year if the tests prove it is beneficial.
- BBC Panorama: When Will We Be Safe? airs at 7.30pm on BBC One tomorrow.
