Airborne pathogens: controlling words won’t control transmission

Strong and consistent evidence for a predominantly airborne mode of transmission emerged early in the pandemic4 but was denied or downplayed by WHO and national public health bodies for years.5,6 In November, 2022, WHO's outgoing Chief Scientist reflected that the organisation's greatest error in the pandemic was to deny early on that the virus might be airborne and design a global preventive strategy around an assumed droplet mode of transmission (ie, handwashing and surface cleansing).7 Handwashing is still widely assumed to be the most important preventive measure against COVID-19, whereas precautions oriented to reducing airborne transmission (ie, improving indoor air quality and wearing high-quality, well-fitting masks in high-risk settings such as poorly ventilated spaces) are ignored or downplayed.8 This new WHO report appears to assume that because some infectious disease experts believe that the SARS-CoV-2 virus is airborne only “situationally” (ie, under unusual conditions),1 the issue is therefore scientifically complex. An alternative explanation, which has been extensively discussed in the peer-reviewed literature,9,10 is that dominant voices in the infection prevention and control community did not grasp the basics of airborne transmission and failed to listen to people who did.5,8 The report proposes a new era of multidisciplinary research made possible by a “consensus” on terminology.1 This reasoning overlooks the importance of discipline-specific language and concepts. MU has received research grants from the Canadian Institute of Health Research, Natural Sciences and Engineering Research Council of Canada, and Social Sciences and Humanities Research Council of Canada.