“Doctor, why does my dog get yearly revaccinations when neither of my children nor I get vaccinated every year?”
While the canine immune system development is similar with that of humans, the difference between the medical approach and the veterinary tradition of immunisation against infectious diseases is striking.
A yearly revaccination of adult pets against distemper (CDV), adenovirus (CAV) and parvovirus (CPV) diseases is scientifically unwarranted, since these live vaccines are long lasting.
In the human counterpart of canine distemper, the live virus vaccines against measles are given to people twice in their whole lifetime. Dogs, however, may be treated to a dozen or more boosters during their lifetimes. Why?!
When talking to immunologists the reason is mainly historic:
In the first years of vaccine development, maximum protection was thought to be achieved by maximum antigenic stimulation. At the time this seemed to be the right thing to do and It became common practice in subsequent vaccine developments, without asking why.
However, in recent decades, the frequency of vaccination has become a matter of debate.
The high incidence of suitable antibody levels in a large population implies that annual revaccinations against CPV, CDV and CAV isn’t necessarily needed. Because protection against most viral diseases is antibody mediated, the scientific arguments in favour of less frequent revaccinations are traditionally based on antibody titers.
The WSAVA Vaccination Guidelines states “The presence of antibody (no matter what the titer) indicates protective immunity and immunological memory is present in that animal. Giving more frequent vaccines to animals in an attempt to increase antibody titre is a pointless exercise. It is impossible to create ‘greater immunity’ by attempting to increase an antibody titre.”