I'm not sure the risks of VHD in indoor rabbits is lower. In fact in some ways I think it might be higher :? VHD can survive for several months in the environment and can be brought in on shoes. I don't often climb into my rabbit's outdoor runs so in the event that I did have it on my shoes, I wouldn't be placing it directly in their environment. However I would be doing so if it was on my shoes and I walked into my house if my rabbits lived indoors.
I wouldn't let the bonding issue worry you and would definitely go ahead with Max's vaccination in any case. The VHD vaccination is made from the VHD virus so it is extremely effective, so you would be ensuring that Max is protected in any case. Think about it this way - in the event of you bringing VHD into the house, if you have 2 unvaccinated rabbits, both will succumb to it. If you have one unvaccinated and one vaccinated rabbit, then it is likely that the vaccinated rabbit will be fine and the unvaccinated one will catch VHD. Not a pleasant thought but ultimately that's the whole point of vaccination!
It's a tricky one for your poorly bun because the levels of VHD in the environment and the number of deaths it causes are pretty unknown, but I think you just need to discuss the pros and cons with your vet and take a view based on her state of health and whether her health is likely to improve further. But I would definitely vaccinate Max in any case.
