Estimated cost, $1 billion. The only thing slowing them down is legislation - they want to make money by resolving people's medical issues with novel techniques.
Solving Long COVID: NIH $1 billion. Nothing. Probably the biggest problem here is that groups like Pfizer are being banned from doing research by an NIH ethics committee that says trading 1 life to save 1,000 is an unacceptable trade.
Now I'm not against the NIH spending $1 billion on research. Better than feeding it into the military-industrial complex for example. But the evidence here is if you want a research team to fix a known problem, the people who know how work at Pfizer not the NIH. Now Pfizer probably can't do that trick of getting results on demand, but there'll be some company that can - assuming it is possible. There are a lot of companies so there are lots of attempts being made.
[0] https://en.wikipedia.org/wiki/Pfizer-BioNTech_COVID-19_vacci...