If anything, the reverse
Because the parents most likely hadn't had any vaccinations there's a chance that any infection came through the mothers
They were, I think, too young for the vaccination but once they started dying what have you got to lose. But banging in a full dose maybe was too much for them
This really is a learning as you go
It sounds like they haven't got a clue but you couldn't be further from the truth. It's done in consultation with the vet
This is an ongoing problem
There was a colony of dumped cats (thanks Covid) that hadn't been sterilised or injected or anything so inbreeding just was a thing and we had, god I don't know, 20-30 cats and kittens over a period of time. Some lived, most didn't. Some were rehomed. I like to think that this colony has been sorted but there's others.
This current lot is coming from a farm I believe. There's still several pregnant queen's that for one reason or another we've not got yet. But the speed after having a litter to getting pregnant with another litter is unbelievable. So there a vanishingly small time window to halt the problem
As for the life expectancy of this current new batch... shrugs... I'll be surprised / delighted if half of them make it
And that's another problem, it's this charity's policy to not rehome a kitten until its around 6 months old to ensure that they're chipped (now a legal requirement) fully injected and most importantly of all, sterilised. As despite previously supplying a voucher for the procedure to be done for, basically free, people can't be bothered and we've had super young cats returned because they weren't done as promised and were pregnant and they weren't wanted any more. Makes my blood boil. This is not a national charity, it only started just over a year ago and they've pretty much permanently got over 100 animals they're caring for