You are correct. Corona viruses have been around for a while and they infect people, animals and birds. The Pirbright patent filed in 2015 and approved in 2018, was for an avian IBV (infectious bronchitis virus).  In 2003 there were several patents filed during the SARS-CoV outbreak. It is unclear at the present time if there is a patent application on SARS-CoV-2 2019 novel coronavirus which Wuhan would have filed since they are responsible for it's particular genetic sequencing.  From all of the "actual experts" looking at this novel virus, they seem to continue to point to a modified bat coronavirus. Remember, scientists in China released a study showing how they were able to get this horseshoe bat coronavirus to cross species by adding a HIV genome sequencing to the protein envelope. This allows the virus to cross species. I think a little research is needed before jumping on a particular band wagon. That still does not exonerate Gates since his muggy mitts are all over vaccine development and he spreads much money around. But Pirbright does not own the patent on this flavor of coronavirus.