Other veterinarians question whether or not it is harmless to annually give vaccinations when there is already adequate immunity present. (marvistavet.com)
Occasionally, a vaccinated pet may not develop adequate immunity and, although rare, it is possible for these pets to become ill. (web-dvm.net)
Similarly, if the mother cat was not up - to - date on her vaccinations before giving birth, she may not have passed adequate immunity to the babies. (vcahospitals.com)