'Trailblazing' use of light to kill viruses given UK government support

Use of a new type of ultraviolet light to safely kill airborne viruses, such as SARS-CoV-2 which causes Covid-19, has come a step closer to reality with £296,000 of new government funding for a project led by the University of St Andrews to investigate its safety and efficacy. If the project is successful this new type of ultraviolet light could be safely used to significantly reduce the risk of person-to-person indoor transmission of Covid-19, as well as other diseases such as influenza.

Research, carried out jointly with NHS Tayside and the University of Dundee, has already found that the particular type of ultraviolet light known as Far-UVC could be safely used to disinfect air in public places.

Now two new awards from the UK Government’s Department of Health and Social Care (DHSC) will allow two studies to bring the technology closer to implementation. The first grant of £160,000 will allow skin safety studies with volunteers to be carried out in clinical trials at Ninewells Hospital in Dundee while the second award of £136,000 will allow virologists from the Biomedical Sciences Research Complex at the University of St Andrews to conduct studies at a bioaerosol facility at the University of Leeds.

The bioaerosol study will assess the effectiveness of Far-UVC light by releasing bacteria and viruses in a room-sized area and then testing the level of viral reduction. Computer simulations run by the University of St Andrews and Fluid Gravity Engineering will also examine airflow, viral spread and Far-UVC inactivation of viruses through numerical modelling.

Since the research was published in Photodermatology, Photoimmunology and Photomedicine last year, a large interdisciplinary team has been created to expand knowledge on the potential for Far-UVC light with colleagues at Ninewells Hospital, the Universities of St Andrews, Dundee and Leeds, Heriot-Watt University and Columbia University in New York along with local companies Fluid Gravity Engineering in St Andrews and Ten Bio in Dundee.

Team members were invited to present their findings at a recent workshop led by the Innovations and Partnership team in NHS Test and Trace. The event was held to evaluate and accelerate the most promising research and technologies available which may provide safer spaces from Covid-19 and other diseases. As a result, the team was awarded "acceleration funding" for the project.

The use of ultraviolet-C (UVC) light is already well established as a technology for the inactivation of viruses and both conventional UVC and Far-UVC light are already known to be effective at inactivating viruses like SARS-CoV-2 (the virus responsible for the Covid-19 pandemic) on surfaces and in air. However, conventional UVC light can cause acute skin reddening and eye damage, limiting its use in occupied spaces. By contrast, when appropriately used, Far-UVC does not appear to produce the same negative effects, and existing studies show it is likely to be safe to use in occupied indoor places.

Dr Kenneth Wood, of the School of Physics and Astronomy at the University of St Andrews, said: "We know that Far-UVC light efficiently destroys viruses and bacteria in laboratory experiments. Scaling this up to room-sized environments in the Leeds facility will allow real-world testing of this new and very promising technology."

Dr Louise Fletcher, an expert in environmental microbiology at the University of Leeds, said: "The bioaerosol facility is a sealed chamber the size of a single-occupancy hospital room where we can securely test the effectiveness of Far-UVC light. We can mimic airflow to represent different types of building ventilation and environmental conditions. Importantly, the results will tell us how effective Far-UVC may be in a real-world situation. Although the test will involve a live virus, it will not be the virus that causes Covid-19."

Dr Ewan Eadie of Ninewells hospital said: "Far-UVC light has the potential to revolutionise the fight against airborne transmission of not just SARS-CoV-2 and its mutant variants, but all airborne viruses including seasonal influenza. However, there are a lack of human safety data and an urgent need for more safety information on this deployed technology, which our clinical trial will address."

The new clinical trials will allow the research to investigate changes in the skin to both acute high-dose Far-UVC exposure and to repeated lower dose exposures.

Research publication references are available at the following links:

1. "Further evidence that far‐UVC for disinfection is unlikely to cause erythema or pre‐mutagenic DNA lesions in skin" [doi.org/10.1111/phpp.12580]
2. "Extreme Exposure to Filtered Far‐UVC: A Case Study" [doi.org/10.1111/php.13385]
3. "Minimal, superficial DNA damage in human skin from filtered far‐ultraviolet C" [doi.org/10.1111/bjd.19816]

Issued by the University of St Andrews Communications Office as News item.