The UK Health Security Agency (UKHSA) announced on Wednesday that there is no evidence to support the effectiveness of N95 or similar masks in protecting clinically vulnerable people from serious illness caused by COVID-19. While regular surgical masks are loose-fitting, N95 respirators are designed to form a tight seal around the nose and mouth and are highly efficient in filtering airborne particles. In a previous publication, the UKHSA stated that low-quality evidence suggests N95 respirators or their equivalent may be more effective than surgical masks in preventing COVID-19 transmission in healthcare settings. However, a rapid review published on Wednesday found no evidence to support the efficacy of N95 or equivalent respirators in protecting at-risk individuals from COVID-19 in community settings. Despite screening thousands of primary studies, the researchers could not find a single study examining the effectiveness of these masks. The review concluded that no evidence could be presented and called on governments to commission high-quality trials to address this issue. The use of masks has been a controversial issue during the pandemic, with conflicting studies and changing guidance adding to the confusion.