Both those sources may be out of date now (July and October). While there is limited experimental evidence for airborne transmission except in animals, there i

Both those sources may be out of date now (July and October). While there is limited experimental evidence for airborne transmission except in animals, there is even less evidence for fomite & respiratory droplet transmission. The claim that "lack of infection spread in hospital settings" rules out airborne transmission due to masking is also questionable. The opposite seems true. As I understand it, infections in hospital settings have been routinely documented throughout the pandemic despite masking, contact protocols, etc. - which implicates airborne rather than droplet/fomite transmission. This is a really good article in the Lancet recently which solidified my opinion on this. It offers 10 items of evidence for airborne transmission being the primary driver of the pandemic. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00869-2/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... For me, the key points are: > Second, long-range transmission of SARS-CoV-2 between people in adjacent rooms but never in each other's presence has been documented in quarantine hotels.7 > Sixth, viable SARS-CoV-2 has been detected in the air. In laboratory experiments, SARS-CoV-2 stayed infectious in the air for up to 3 h with a half-life of 1·1 h.12 Viable SARS-CoV-2 was identified in air samples from rooms occupied by COVID-19 patients in the absence of aerosol-generating health-care procedures13 and in air samples from an infected person's car.14 Although other studies have failed to capture viable SARS-CoV-2 in air samples, this is to be expected. Sampling of airborne virus is technically challenging for several reasons, including limited effectiveness of some sampling methods for collecting fine particles, viral dehydration during collection, viral damage due to impact forces (leading to loss of viability), reaerosolisation of virus during collection, and viral retention in the sampling equipment.3 Measles and tuberculosis, two primarily airborne diseases, have never been cultivated from room air.15 > Seventh, SARS-CoV-2 has been identified in air filters and building ducts in hospitals with COVID-19 patients; such locations could be reached only by aerosols.16 > Eighth, studies involving infected caged animals that were connected to separately caged uninfected animals via an air duct have shown transmission of SARS-CoV-2 that can be adequately explained only by aerosols.17 > Tenth, there is limited evidence to support other dominant routes of transmission—ie, respiratory droplet or fomite.9, 24 Ease of infection between people in close proximity to each other has been cited as proof of respiratory droplet transmission of SARS-CoV-2. However, close-proximity transmission in most cases along with distant infection for a few when sharing air is more likely to be explained by dilution of exhaled aerosols with distance from an infected person.9 The flawed assumption that transmission through close proximity implies large respiratory droplets or fomites was historically used for decades to deny the airborne transmission of tuberculosis and measles.