1) it seems to take about a week for strong immunity to develop after vaccination
2) the immunity only seems to reliably last about 10 months, so rabbits done prior to this should be re-vaccinated.
3) the virus can certainly spread on contaminated cages, equipment, feed, rabbit skin, human hands etc etc. It has often been found that when they put new rabbits into the cages of rabbits that died from calici that they lose those rabbits too.
4) its hard to say how long it lasts for sure in the environment as it can depend on the conditions. Some research papers suggest the virus can survive for months under ideal conditions. There is also some suggestion that there may be some continual re-contamination of the environment from a few rabbits that become persistent carriers. My gut feeling is that about one month's freedom from clinical disease is generally pretty safe under practical conditions where there has been a serious effort to clean and disinfect the premises.
5) I think there has been some talk in show circles of the vaccine causing infertility. We haven't experienced any problems at all in farm rabbits despite doing more than 10,000 does per year.
6) the vaccine contains an oil adjuvant and so can cause some swelling at the site of injection, which could be a problem in show rabbits. Some people with miniature breeds give a smaller dose (0.5-0.75 mL) vs 1.0 mL normally. The dose can also be split into more than one site to spread the irritation. It can also be injected elsewhere than the neck to make it less obvious.
7) there are other things you can do to help control calici eg, keep insect populations down with sprays; keep rabbits indoors; disinfect cages and equipment regularly; care with handling dead rabbits (wear protective clothing and gloves and change before handling healthy rabbits); care with bringing new rabbits in (keep in separate quarantine are for 3 weeks). But these are only ancillary measures compared to vaccinating.
8) although there seems to be more than one strain of the virus floating about, the current vaccination seems to give very good protection against all strains for all practical purposes. Besides, its the only vaccine available in Australia. We haven't noticed any dimunition in the efficacy of the vaccine in association with the identification of other strains.
9) farmers generally vaccinate with a 1.0 mL at 12-14 weeks of age when rabbits are selected as breeders, as apposed to being sent for processing. However young rabbits between 6-14 weeks are also susceptible. Some farmers give a small dose of 0.1-0.2 mL dose at 5-6 weeks to tide them over until they get a full dose at 12-14 weeks if kept. Rabbits under 6 weeks are generally not susceptible.