There are a couple of vaccines available but generally those are for larger breeders. I did not get mine vaccinated - low risk for those things.
I don't do annual checkups - just not affordable with thirteen ducks. I try to do some basic home care, but for things like prolapse, extreme lethargy, and an inflamed toe that did not respond to treatment, I have taken the ducks in.
I was told that vaccines are not generally necessary for ducks in small, home flocks. I, like Amiga, don't take them in for "wellness visits". Not financially feasible with 9 ducks, but also, I think the stress of riding in the car, being in a carrier, then at the office, might be too upsetting to justify it. I do not hesitate to run them into the vet if I feel that there is something serious going on or something that may turn serious. That is just my way of doing things.