Many studies have been done exploring the effectiveness of UVC light in killing bacteria and inactivating viruses. Here are some excerpts of a few notable studies:

Journal of Virological Methods

Inactivation of the virus that induces severe acute respiratory syndrome, SARS-CoV published in the Journal of Virological Methods

In this study, UV-C light was used effectively against the virus that induces SARS-CoV.

Columbia University Medical Center

Columbia University Medical Center Study Shows The Effectiveness Of UV-C light to check the spread of seasonal epidemics.

In this study, aerosolized H1N1 virus—a common strain of flu virus—was released into a test chamber and exposed to very low doses of 222 nm far-UVC light. The far-UVC light efficiently inactivated the flu virus.

“A safe and efficient method for limiting the transmission and spread of airborne-mediated microbial diseases, such as influenza and tuberculosis ... and unlike flu vaccines, far-UVC is likely to be effective against all airborne microbes, even newly emerging strains.” David J. Brenner, PhD, the Higgins Professor of Radiation Biophysics at the Vagelos College of Physicians and Surgeons and director of the Center for Radiological Research at Columbia.