https://www.pennmedicine.org/updates/blogs/penn-physician-bl...
> The principal mode by which people are infected with SARS-CoV-2 (the virus that causes COVID-19) is through exposure to respiratory droplets carrying infectious virus.
https://www.cdc.gov/coronavirus/2019-ncov/science/science-br...
From what I can tell, you may have your flu/covid mixed up. Covid is spread through respiratory droplets, the spread of which is reduced by wearing a mask.
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/PIIS0140-6...
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.
Influenza is pretty promiscuous. In normal conditions, very few people aren't exposed to it: either their existing immune resistance (vaccinated or otherwise) is up to the job, or it isn't.
Mutation is therefore the primary driver of flu, year upon year. This is why vaccines are continually reformulated for a best-guess at what strains are going to be dominant.
We had just concluded a northern-hemisphere flu season when travel restrictions started to kick in. This was followed by at least a 90% reduction in international travel, and for most of what remained, it was mandated that new arrivals isolate for long enough to eliminate any influenza they might have carried.
Lockdowns would mean less mutation to begin with, since it happens in human hosts. And such mutations as did present are going to have a tough time jumping oceans, and even when they do arrive, spreading through the populace is substantially inhibited.
Ironically, the universal mask mandates are likely to be more effective against flu than against COVID. Like it or not, masking has minimal effect on spreading aerosols, although using a "real" mask, and being pretty careful to wear it right, can mitigate inhaling those aerosols.
Influenza is believed to be spreadable through aerosols, but the primary vector is droplets, while the opposite appears to be true for SARS2. Bog-standard cloth masks are fairly good at keeping droplets off people and surfaces.