Life happens, things get forgotten and sometimes a pet misses a dose of a vaccination. Does it really matter? Yes, absolutely. Vaccines prevent many serious infectious diseases. Can we do anything to make sure that they’re still protected? Of course! The biggest challenge in this situation is that there are many variables at play given an individual pet’s circumstances.
Immunology 101
Understanding the basics about how the body’s immune system responds to a vaccine helps to explain why vaccine boosters are necessary at specific intervals. Vaccines, bacterial and viral infections all stimulate the body to produce specific proteins called antibodies, but there are several different types of antibodies. The first time an immune system is exposed to a new infection or vaccine, the immune system is “primed” as an IgM antibody response occurs. This response is generally short-lived, which is why booster vaccinations are needed to stimulate the production of longer-lasting protective IgG antibodies. Without properly timed vaccines to mount an antibody response, vaccine failure can occur.
Kitten and Puppy Vaccines
The vaccination schedules for puppies and kittens are a little different than those for adult animals because of the presence of maternal antibodies or passive immunity. This essentially means that the antibodies that a mother transfers through the placenta protect the puppy or kitten for a period of time, but have typically waned by 16 weeks of age. As a result, many vaccines should be given every two to four weeks from six to eight weeks of age until 16 weeks of age.
If a dose of a vaccination is missed during this time frame, it’s important to give the next vaccine as soon as possible, then booster it two to four weeks later. Without a second properly timed booster vaccine, a pet will not form an appropriate antibody response, which can protect them from the virus in question.
Adult Vaccines
The timing of vaccinations for adult dogs and cats varies a bit from that of puppies and kittens because there are no maternal antibodies to content with. The first time that a pet receives a new vaccine, even as an adult, a booster vaccine should be given two to four weeks later. If an adult pet misses one of their regular annual or every third year vaccinations, they might still need to have an additional booster vaccine to be sure that they have an appropriate immune system response. However, the need for an additional booster varies based upon the specific vaccine in question and how long it is overdue.
If your adult pet has missed a scheduled vaccination or has not had any vaccines, it is always better to have the vaccine given sooner rather than later. If an additional booster is needed, your veterinarian will be able to tell you so, given your individual pet’s circumstances.
Rabies Vaccine Exception
The rabies vaccines for dogs and cats is the exception to the booster rule. The reason for this is that the rabies vaccine given acts as the immune system “primer.” Unlike many of the other diseases for which pets are vaccinated, rabies is a relatively slowly progressing disease. Therefore, if a pet is then exposed to rabies, they would then have enough time to develop a longer-lasting protective immune response.