I get slightly different stats on the # mutations - HB-04 has some indels that need corrections. Keeping HB-01 as the reference (should maybe be WH-01 though, as that’s the oldest sequence):
IPBCAMS-WH-01/2019: 3 mutations (2 non-syn / 1 syn)
WIV04/2019: 0 mutations
Hu-1/2019: 1 mutation (1 non-syn)
IVDC-HB-04/2020: 2 mutations (2 non-syn) (however, I don’t believe these, so I think this should also be 0 mutations)
I agree with Trevor that the mutations in HB-04 are suspect - right next to each other, non-synonymous, close to a poly-T stretch, and this sequence also needed some manual editing for indels. I think these are probably not correct and that sequence would then also be identical.
As for IVDC-HB-05, I agree with everybody that this sequence is definitely wrong (clustering of mutations, wacky ts/tv ratio, etc). If I do my very best to eliminate sequencing errors that I have commonly observed over the years, then I get a maximum of 7 mutations in this sequence, 4 of which are non-synonymous. These 7 can’t be excluded as likely errors (unlike the other 46 mutations in this sequence), but I think they still represent a (substantial) over-estimation.