There are biolabs in the Ukraine, as confirmed by Nuland in the Senate hearings. Whether they have bio-weapons or medical research, who knows, but you can perhaps understand that the Russians might be concerned?
What's really amazing about this story that only days ago it was painted as a Q-anon theory. Turns out it was real. We are neck deep in propaganda from all directions, but most people think it's only coming from the Russian side.