DeepSeek

[Brooke]

Minced monkey kidney.   

Of course, Wistar's WISH was found to be HeLa contaminated like many others.

I think it's from biopsy from epithelial kidney cells from one living monkey in the 60's.  Not from a bunch of monkeys who were killed and their kidneys minced.  The cells from that monkey were from then on grown in labs and ended up mutating into what is used as Vero today (i.e., no longer regular monkey cells, but different in numerous major ways that make it suitable for other purposes and no longer the same as a monkey's cells).

In biology work, at a basic level, cells are just little machines that have different DNA and proteins in them.  You alter the DNA and get cells that work for this or that purpose.  Any process using cells -- not just some things with Vero, but making whiskey, beer, wine, yogurt, cosmetics, probiotic supplements, cheese, etc. -- is subject to getting contaminated with some organisms you don't want if you aren't careful.

Cell lines are part of the standard tool set in biology.

[icepac]

The “vero of today” has benefitted from years of forcing mutations in vitro beyond the mutation that caused immortality to make it safe but it originally came from monkeys known to host SIV. 

The dangers with using monkey kidney as a substrate were well known even in the 50s and some were flippant about the risks and weren’t worried about anything but beating polio to earn the nobel prize and secure funding forever. 

Luckily, technology has come a long way toward “cleaning up dirty cell lines” but…….it still originated as minced monkey kidney.

[Brooke]

The “vero of today” has benefitted from years of forcing mutations in vitro

Yep.

came from monkeys known to host SIV. ... The dangers with using monkey kidney as a substrate

Yes, SIV is a monkey virus that can infect monkey cells.  What can also infect vero cells:  measles, rubella, polio, flu, RSV, etc.  It's why vero is used.  Viral substrates have to be able to propagate viruses.  It's their purpose.  When you use such, obviously, you need to make sure it is infected with what you want and not with anything you don't want.  This is a standard microbiology tool.

Like internal combustion engines use gasoline.  But gasoline can light on fire, which can harm people.  Yes -- but those features are also necessary for it to be a fuel.  And you build engines and gas tanks such that they typically don't spray burning fuel all over.  Does it still happen sometimes?  Yes.  But you use your standard engineering practices to make it rare enough such that gasoline and engines are viable to use.

Same goes for vero.

it still originated as minced monkey kidney.

Maybe.  But I think it more likely the original source was a biopsy.  Monkeys are expensive.