Because the SARS-2 virus and its 11 mutated versions are all well documented each and every genetic base pair... i assumed months ago that claims like yours were not true, but you are sadly correct. The CDC and all of science admits that the SARS-2 virus, though trivial to map out, has never ever been isolated, like any other virus has. there is not a single actual pure isolated sample of the whole virus in any lab freezer, and it is NOT ISOLATED, but exists in computer databases. There are no possible identifiable pictures, but the surface was 3d protein modeled by protein folding computer programs to generate simulated photos. **THERE ARE NO ISOLATES!!** ====== Nevertheless, sars-2 is probably real and assumed to be the cause of covid-19 infections A skeptic would claim its all made up, but something got wuhan residents sick. ==== = = = = = - - - - - -- - EDIT addendum : The 11 version strains of SARS-2 (covid-19) are named after letters of the alphabet and tracked country region to country region with great interest. 9 are listed on this page : https://en.wikipedia.org/wiki/List_of_strains_of_COVID-19 11 are in the last paper I read **11 versions of covid-19 sars-2** =========== 7 major branches in july 2020 : https://phys.org/news/2020-08-strains-sars-cov-.html that page overlook L strain 7% the official killer strain. It omits L strain because China prevented tabulation count data on strain L. 7 major branches not 6 though, and 11 total if pedantic. see? Its called science. Read a science paper.