Repeated vaccinations are a key part of shielding your young pet, but this is not because the extra vaccines add to your kitten or puppy's immunity. The reason that newborns require repeated shots is that the original vaccine might never have activated in the first place, and this would be because of the antibodies passed down by the mom. Puppies and kittens alike can be born with antibodies they've inherited, or they can gain these through first milk. While the antibodies fight to keep newborns healthy, particularly while their own immune systems are still weak and growing, antibodies might also fight off the vaccines.

The thing is, there is no telling whether a vaccine was accepted or whether antibodies deactivated the vaccine. Maternal antibodies will leave a pet's system after a few months or so, but there is no hard and fast timeline for this. Each puppy and each kitten will develop on a different schedule.

Usually speaking, however, a mother's antibodies will protect newborns (and ward off vaccinations) for the first eight weeks. That is why repeated vaccinations will typically start at the eight-week mark. For most kittens and puppies, a vaccine will take root if they are vaccinated at 16 weeks old, usually the last time these boosters are administered.

However, some young pets can accept vaccines right away at eight weeks old. If these newborns aren't vaccinated, and the mother's antibodies have worn off, then they are vulnerable to illnesses. That is why vaccines should start at this point. Other pets can accept vaccines at 9 weeks of age, some at 11 weeks old, and so on, so it is unsafe to wait 16 weeks before administering such important shots. That is why there are rounds of boosters for kittens and puppies; the aim is make sure they're protected, no matter the time "maternal immunity" wears off.

These vaccine series that must be administered more than once include:

• Adenovirus
• Calicivirus
• Canine distemper
• Feline viral rhinotracheitis
• Panleukopenia
• Parvovirus

If you have a new puppy or kitten, or if you are anticipating a new pet in your family, be sure they get the early protection they need. Start taking care of these vital vaccinations when you contact a veterinarian today!