The NIH page links to 4 studies on coronaviruses where lysine is mentioned, but 3 of them have nothing to do with using lysine supplementation to combat the virus. They are talking about the structure of the virus' proteins and how they might work. Lysine is an amino acid, one of 20 building blocks of proteins. Viruses and cells are made of proteins. These papers are mentioning specific lysine molecules in the structure of the virus or the host cells that have a specific function.
The other paper is a completely virtual simulation trying to design an inhibitor based on what we know of the coronavirus structure to hopefully narrow down the most likely candidates to be good antivirals. This field is very interesting but has a long way to go. They have no idea that the computer's picks will actually be effective in reality, and besides, lysine was not one of the picks. There were a few variations of peptides that include lysine as part of their structure, but again, lysine is a building block. A chemical reaction would have to bind lysine and the other amino acids together to make the molecule that the computer predicted would be helpful. This is not at all the same as L-lysine you can buy as a supplement.
