Despite problems, vaccinations are still a pet owner's best line of defense against distemper and parvovirus that can kill puppies and young dogs, against rabies that will kill dogs - and people - of any age, and against other contagious diseases that can cause short term and long term health problems. (canismajor.com)
However, since FeLV + and FIV + cats can carry several other contagious diseases, it is recommended that certain people who are immunocompromised avoid contact with those cats. (thesprucepets.com)
This can also help prevent the spread of other contagious diseases, such as kennel cough. (ctvsh.com)