viruses are too small and go right through masks.
Any publications about the virus alone passing through a "mask" would be true, as it is only about 100 nm in diameter, so only high containment PPE is going to stop it. That does not mean regular "masks" do not help prevent the spread of the virus within real, human populations, where it is transmitted on much larger particles, as everyone should know by now.
There is ample scientific evidence that masks reduce the spread of this virus (1, 2), and would reduce the spread of flu and cold viruses if people wore them during those seasons as well. This is not open to debate. It is scientific reality at its finest - directly helping people! The hard data is in on masks. They absolutely help. There can be no doubt.
All infectious respiratory agents are spread by exhaled aerosols and droplets from the carrier to the unsuspecting target. This issue about the value of masks seems to be a no-brainer, but that designation may have different meanings for this situation.....
Rest assured there is no doubt that the use of face masks, properly made and worn properly, can be very significant in reducing infectivity by minimizing spread of COVID-19. Wear a mask - it protects everyone. The CDC has the hard data to prove it.
1.
https://www.thelancet.com/journals/lancet/article/PIIS2213-2600(20)30352-0/fulltext
2.
https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-mask/art-20485449