The only reason for the series of vaccinations for the young animals is to "catch" them when the maternal antibodies have worn off and the vaccine will be effective. Because each animal is different and maternal antibodies don't wear off at the same time, they do the series with the intent that they all will be vaccinated with a minimal amount of time without maternal antibodies. You could give ONE vaccine after about 16 weeks or so and not have to do the series. If the animal is an adult then one vaccine is fine even if they have NEVER been vaccinated before. You don't boost immunity, it is there or it isn't. I believe the question was regarding a ferret that was not a kit? Your vet is wrong in advising a second vaccine 30 days later and is putting your ferrets health at risk. Ferrets are already over vaccinated with the yearly "booster" protocol being the norm, but recommending a series for a ferret that maternal antibodies have most definitely worn off is very negligent. Vets and people have to realize that vaccines are not water and stop giving them like they are. If your vet is not going to educate him or herself, then it is up to the owner to and to say no to that practice of a series with adults that has no scientific basis and is health endangering. ~Amy~ [Posted in FML 6101]