I don't know what vet he is using, but Tom Pennycot, if he is still active, is the only vet with avian experience that I know of. Tom is based at Auchincruive College. I have heard of vets recommending vaccination against PMV as a cover all, but if this is the case then it is a stab in the dark. For safety sake, I very much doubt anybody would go near to help vaccinate until proper precautions have been set up, if there are any.