The development of effective vaccines and treatments for COVID-19 will be crucial in the ability of our healthcare and public health infrastructure to address this pandemic in the long-term. From repurposing existing drugs to developing new therapies and studying human immune responses, Columbia’s researchers are investigating multiple public health approaches and treatment options to treat and prevent COVID-19. A new study by researchers from Columbia University Irving Medical Center has found that more than 99.9% of seasonal coronaviruses present in airborne droplets were killed when exposed to far-UVC, a particular wavelength of ultraviolet light that is safe to use around humans. The researchers used a misting device to aerosolize two common coronaviruses in the study. The aerosols containing coronavirus have then flowed through the air in front of a far-UVC lamp. After exposure to far-UVC light, the researchers tested to see how many of the viruses were still alive. The researchers found that more than 99.9% of the exposed virus had been killed by very low exposure to far-UVC light. From the results, the researchers estimate that continuous exposure to far-UVC light at the current regulatory limit would kill 90% of airborne viruses in about 8 minutes, 95% in about 11 minutes, 99% in about 16 minutes, and 99.9% in about 25 minutes.