New data suggests that inexpensive, high-efficiency particulate air (HEPA) filters can effectively scrub SARS-CoV-2 particles from the air in hospital COVID wards. The result validates previous studies carried out in controlled conditions. Currently, HEPA filters are not routinely used in hospital settings, but researchers suggest they could could help mitigate the risk of tramission of airborne viruses. In addition a new study has demonstrated the effectiveness of mask wearing, with surgical masks proving more effective than those made of cloth. The trial, which involved 350,000 participants in Bangladesh, is the latest in a long line of studies demonstrating mask efficacy - but this is the first randomised control trial of its kind. We ask if this gold-standard trial will prove to be the final word on the effectiveness of masks. News: Real-world data show that filters clean COVID-causing virus from air News: Face masks for COVID pass their largest test yet Subscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.   See acast.com/privacy for privacy and opt-out information.