Doesn’t Occam’s razor say that it’s just the fact the pandemic is destroying society and there is immense pressure from everywhere to accelerate usually very slow and bureaucratic processes because the risk reward ratio is completely different than the one for a vaccine for more contained diseases?
Why hasn’t the news or our medical governance brought up the fact that a small intranasal injection can greatly prevent transmission?
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8026810/
When you say "why isn't x happening" I'd like to invite you to think about what x would look like, in practice, and what it is you actually are expecting.
This has nothing to do with how lucrative it is. Just how practical. Note the author doesn't even say this measure can replace PPE and other preventative measures.. just add to them.
I’ve also read claims that these respiratory viruses are on the order of microns and most masks are pointless, unless specifically designed for this.