Israel’s Aura Smart Air (reported here previously) is being widely used to protect UK buses, including the transport of key workers to their places of employment. The system kills the virus and replaces the air on the bus five times an hour. Sensors also monitor air quality and can alert the driver.
https://unitedwithisrael.org/israeli-tech-defends-buses-in-uk-against-covid-19/
https://www.aurasmartair.co.uk/transport.html#/
https://www.busandcoachbuyer.com/alfa-travel-deploys-aura-air-after-successful-trial/