Without wanting to sound insensitive, I'd want to know on what basis the vaccinations are being regarded as the cause of death for the two rabbits? Was the causality of death actually proven (necropsy?) and if so what were the circumstances - ie was it a bad reaction, if so when did it appear, how soon was it caught and how was it treated, were the rabbits already either knowingly or unknowingly ill or subject to some sort of immune system deficiency, was the batch bad or improperly stored/administered etc.
I'm not discounting that there are some individuals who can and do have reactions to vaccination, just as there are to any medication or treatment no matter how safe it fairly rare and that when they occur they are usually mild and transient - ie localized itching or swelling. Even more rarely those reactions could conceivably result in death but "possible" is not "probable" and there's a lot of context missing.
It also needs to be viewed in relation to the degree of risk - for example, as a more familiar example consider a spay surgery. We know we can do things to reduce the risk (using a specialist, doing a through check-up, doing bloods, using monitoring, safe anesthetics vs older style ones etc) but there is still a risk. Some rabbits DO die in surgery. If we consider the vast majority come through fine, the many and significant benefits and the risks from NOT being spayed (dying by cancer for example, the dangers of nonstop litters back to back, being dumped for being aggressive/territorial etc) the surgery becomes the far safer option.
Likewise with vaccination - there is always a risk of reaction however unlikely. If you live in an area where myxo etc is a risk, given the fatality rates and assuming you have a healthy rabbit the risk of disease likely outweighs the risk of a fatal vaccination reaction hugely.
Living in Australia I wish we had the ability to get it - our government makes it illegal and myxo is absolutely RAMPANT atm. I know of literally dozens of pet bunnies, even ones who live indoors only, who have been put down this year. Shelters are having to halt adoptions and quarantine because myxo affected buns are being brought in and there's the possibility everyone else has caught it. Another rescue I know has had to euthanize many and is still finding more coming down with it. Unfortunately our best protection atm is flyscreen. :foreheadsmack:
