This is the calculation I did months ago. But I am brain injured idiot, so what do I know?
Read this thread to understand the problem with masks as a mitigation measure.
And this key bit:
Another way to look at this, in a simplified, intuitive way is – the better-done population studies suggest that high quality masks, worn by most everyone, properly, may reduce spread by about -20%.
What that means: Instead of an R-0 of say 3, we have an R-0 of 2.4. The virus is still spreading rapidly whenever R-0 > 1. All we managed to do is delay the spread by a few days.
This is why there is the paradox: Proper masks, properly worn, provide a degree of protection to an individual that is wearing the mask.
But community masking has widespread “leakage” in the protocol – many people do not wear high quality masks, they do not wear masks properly, they do not dispose of masks properly, and there are many times when they do not wear a mask.
For masks to effectively prevent Covid, we need to wear a 100% effective mask, essentially 100% of the time, including at home 24×7. There is no such thing as a 100% effective mask, and no one will wear a mask 24 x 7 at home, or even wear a mask at all at home. Yet contact tracing originally showed that a majority of “cases” were transferred at home, from family or social contacts.
The result is that a high-quality mask, properly worn, can reduce your individual risk – but cannot stop community spread. Eventually, everyone will have had Covid and indeed, that is the case today.
If you think masks are a solution, then wear one – to be effective, you’ll need to wear it all the time the rest of your life – or until you get Covid. And you will get Covid eventually even wearing a mask.
Pandemics end via immunity – not masks. A majority of the population has been vaccinated and/or has had Covid or both (a CDC staff member said last week it may be 95% now). We reach immunity via vaccination, getting infected, or both, and that from an evolutionary standpoint, viruses will tend to mutate into less virulent forms, over time. All of these things have occurred.
Most pandemics last 1-3 years. We are now at 2 1/2 years as this one appears to be winding down in spite of and not because of public health mitigations.
But do keep in mind, I am a brain injured idiot with no relevant training and insufficient initials after my name and no blue check on Twitter. In short, I am a random idiot who knows nothing.
Update: Prof. Francois Balloux has a more technical explanation of why community mask mandates do not work. See