Can you point me to the study that shows that?
It's a information bit that's been pretty widely reported in the media, cable news, etc. I don't know of any "studies," but I suspect that if there are any, they might be inconclusive or even contradictory.
I've read studies showing masks were inneffective, and others claiming they are. I've seen videos of people spraying aerosols through various masks, showing some appear to block the spray while others appear not to block anything .... yet viruses are so tiny they easily penetrate even the "effective" masks.
I do not think masks really do much .... atleast for a virus.
Even regular flu vaccines don't work 100% I've seen some that were claimed to work even as low as 50%. We were told that the mRNA vaccines were @95% effective. In a country of 330,000,000 people a five percent failure rate is still a
whole heckuva lot of people, numbers wise. We should not be surprised or alarmed at these breakthrough cases, or be shocked our malignant myrmidon media malcontents would hype this to cause panic and garner ratings.
If you look at the mortality rate of this latest spike, it's way down from the earlier variant (s). Deaths have pretty effectively been "decoupled" from cases.
One can attribute this to possibly (A.) The vaccines
are working, even if to ameliorate symptoms in break through cases, (B.) The D version of
THE ANDROMEDA STRAIN - - - - - oooops, covid 19 is less fatal than the original variant, or (C.) Both A and B.
I am not a biophysicist, virologist, biomolecular transcendentalist, or a wizard, nor did I stay at a Holiday Inn last night. But .... that's my two cents.