There's an Ich vaccine...
..under development. Right?
UFla mentions it in their Ich guide that way....but I've never looked up the current status.
Well I didn't QT mine either and I bought a pretty little fish that looked healthy and it had velvet and I lost every fish I had not once but twice! !
I don't think it's fair to blame the new guy. I don't even understand how than came to be seen as logical.
If things really worked like that the ocean would be devoid of fish.
Dillution only goes so far....fish socialize...eventually there would be zero fish.
Fish have immune systems that work much like ours...when they are compromised, they become susceptible just like we do. When they are healthy, they can be around sick people, just like we can.
Just as with fish, it doesn't take a magic bullet to make a healthy, resistant human...we just have to eat right. If you let your fish eat right and build your fish population very slowly, I think you can expect success...you'll have time to learn how to get the environment right this way, and the magnitude of accidents or incidents will be minimized too.
Don't blame the new guy next time, please...he's new in town and it's not (entirely) his fault.
I'd be very interested in how you've come to have such healthy, disease resistant fish.
There is a book if you're really interested. I'm still getting through it, but it seems more comprehensive than most husbandry books I've read.
From what I've learned about PB from reading here, I think I can get it down to one main point:
He built his fish population over the scope of years, and it wasn't perfect from day 1.
He learned what fish aren't fun to keep along the way.
He learned how to keep fish alive along the way.
He built some amazing contraptions to help his fish along the way.
He had lots of time to do lots of things.
Most people seem to build their fish populations in days or weeks hoping a magic bullet will give them a perfect tank full of fish.
What
they learn along the way is that building a fish population quickly doesn't work out in the long run....or if it does it's rare luck, because look at the disease forum....this counts all cases, failed QT's, failed fallows, no QT's and all.
A big part of this is that most people don't give themselves time to learn anything at all about the fish in their tanks along the way. I don't mean "read books about them" I mean get to know them by taking care of them, over time, in real life. (But you should read books too.

) This time with the fish "along the way" really counts if you're an intelligent human because you learn and invent stuff along the way. That's what we do. Don't short change that!
Instead, the stocking of a tank is usually all said and done before the first mistake has a chance to happen. We hope the magic bullet works!
Do you catch my drift?
I get all of my fish online
Every fish bought online has the same number of brutal, long distance trips over land as the fish at your LFS....plus one more just because we want them $5 cheaper delivered from out of state.
I'd expect online purchases to be even more compromised than LFS fish pretty much every time. Live arrival guarantees are there because they are needed, after all...some get more compromised than others.
Worth considering at the very least when providing accommodations for such fish...be as nice to them as you're able to be.
