Answer: Unless the cats comes into the natural contact with the infectious organisms responsible for the various disease described, the level of the antibodies in her blood will gradually decline. Whether or not this has happened , however, cannot readily be ascertained. Therefore, in order to boost the level of antibodies and keep them at the effective level to combat infection, it is advisable for the repeat vaccination to be performed.
The plasma cells which produce antibodies can ‘remember’ a particular bacterium or virus and if that organism reappears in the body, they then rapidly produce large amount if the specific antibody against it.
For maximum protection it is recommended that vaccination is repeated annually, though the persistence of immunity dose very with the disease. Immunity against FIE can last up to four years with a live vaccine so that after the first annual booster, other may only be needed every two years or so. In contrast, immunity against FRD (cat ‘flu) may be so short that cats particularly at risk, such as stud cats, should ideally be re-vaccinated every six months.
Booster vaccinations are always advisable three to four weeks before known period of stress and exposure to infection, e.g. before going to cat shows or entering a cattery.
Because great advances are currently being made in vaccine production, and the recommendations for the use of different products vary, this is a topic that should always be discussed with your veterinarian.
