This was back in the 90s when getting yearly vaccines was just what we did. (fidoseofreality.com)
Moreover, veterinarians say they may actually lose ground if yearly vaccine requirements are weakened. (articles.orlandosentinel.com)
I remember pulling out my Veterinary Immunology textbook and being shocked that I could find no scientific support for the practice of yearly vaccines for most of the serious contagious diseases. (animalkindvet.com)