Virus mutation is common and inevitable. Even samples taken from a single patient can show genetic variability. Clinically, it does not have as much significance as it does epidemiologically. By tracing the various clades, the exact spread pattern of a virus can be traced.
For anyone interested in looking at the spread of various clades, I suggest this website: Genomic epidemiology of novel coronavirus - Global subsampling To nerds like myself, the phylogeny of the virus is fascinating.
In the report here yesterday, the creator of the covid virus claimed to have inserted HIV genetic material into the RNA string. We don’t know what else was inserted.