Columbia University: UVC, unlike a Covid-19 vaccine, also helps against a mutated virus.
Columbia researcher David Brenner conducted a study in April 2020 into the use of UVC light to kill viruses. He indicates that scientists have known for decades that UVC light has the power to kill viruses and bacteria.
In hospitals and laboratories, antimicrobial UV light with a wavelength around 254 nm is widely used to sterilize unused areas. However, you can use normal UVC light around humans and animals as it can lead to health problems.
Brenner also added that when pharmaceutical companies develop a vaccine against the Covid-19 virus, it will not protect against the next virus, while UVC light can fight a mutated version.
In his research he also examines several UVC variants on different wavelength. This offers a broader scope for future research.