There is much current research attempting to answer such questions and establish guidelines. Unfortunately, biologic systems are so complex that information tends to accumulate slowly and from many different research groups. Studies then need to be independently confirmed, and funding secured, etc., etc. What individual veterinary practitioners can do immediately, however, is perform a detailed risk assessment of every veterinary patient. All our pets have different lifestyles.
Infectious diseases exploit the varied nature of lifestyle.
Our clients at San Carlos Veterinary Hospital are noticing, or will notice soon, that their pets are receiving vaccines that are likely different from those they have typically received. They will be asked specific questions about their animal's circumstances, and a vaccination protocol will be tailor-made for that pet. Some will be administered inoculations for many diseases, others for fewer. Some may receive vaccines more often, others less often. Unfortunately, answers always lag behind the questions.