Last week’s blog post topic was the vaccination series for puppies. One reader had questions about vaccines and titers given after the puppy series is complete. This is such an interesting and controversial topic that I thought we should devote an entire blog to it, and hopefully answer the reader’s question as well.
First, let’s start with a little background on vaccines. There are generally two groups of vaccine types: noninfectious (killed, inactivated, etc.) and infectious (attenuated, modified live, etc.). The noninfectious vaccines don't contain the actual live virus, though they might contain pieces of the virus. They can’t make your pup sick by causing the actual disease. The downside is that many of them don't induce a huge amount of immunity on their own. This means that your pup’s body doesn’t have a large immune response to these types of vaccinations. That is why these types of vaccines generally have adjuvants in them. Adjuvants help to stimulate an immune response. They can also cause vaccine reactions in some dogs.
Infectious vaccines, on the other hand, cause the body to mount the same type of immune response that it would mount if the pup were actually infected. These types of vaccines may contain the entire virus, but it is attenuated (damaged) so that it can’t cause the disease.
We already know that we have to vaccinate puppies in a series because we are fighting maternal antibodies, which are very powerful. This is absolutely necessary for protecting puppies against infectious diseases.
What about puppies who are over 16 weeks and receiving their first vaccination? Should they get an entire series of each vaccination?
The short answer is, maybe. For some vaccines, like the canine distemper vaccination (modified live or recombinant), and the canine parvovirus (modified live), one dose is considered protective if given after 16 weeks of age. This is true of many of the core vaccinations (for an explanation of core vaccines, see last week’s blog). The exceptions are usually the non-core vaccines.
For the Bordetella bronchiseptica vaccination (inactivated; this is the one that a lot of dogs who board at kennels get intranasally), it takes two doses for a dog of any age to mount a proper immune response and incur lasting immunity. However, if a different vaccination for Bordetella bronchiseptica (live vaccine) is used, it only takes one dose if given after 16 weeks. Other vaccinations which need two doses for the dog to mount an immune response include the canine influenza vaccine (killed), and the Lyme (killed) vaccinations.
So, whether your dog needs a series or one vaccine depends on the type of vaccine. This is something that you should discuss with your veterinarian to determine what he or she uses and what is best for your individual dog. If your dog needs a series based on the vaccination that she is receiving and she misses a dose on the schedule, the series will have to be repeated.
Now, on to titers — otherwise known as antibody testing. Basically, antibody testing measures your dog’s immunity to certain diseases. Not every infectious disease has a currently available titer. Titers are a good way to measure immunity for canine distemper virus, canine adenovirus, rabies virus and canine parvovirus. Titers are a snapshot in time. They don't tell you how long your dog's immunity will last, but they do tell you what her status is right now.
If you are interested in titers, you can start to titer your dog after her series of puppy vaccinations have been completed so that you will know how well she is protected against certain infectious diseases. This seems like overkill to me, because the majority of pups will be protected by the series. When your dog is about 16 months old, she will be due for boosters of the core vaccinations. We know that long-term immunity will be present in most dogs for at least canine distemper virus and canine parvovirus after they receive this 16 month booster. In most cases your dog will not be due again for a booster of the core vaccines for three years after her 16 month appointment. At that point (your dog is about 4 ½ years old now), your veterinarian may recommend that you check your dog’s titers.
Canine distemper virus and canine parvovirus (modified live vaccines) have been shown to induce immunity for five years; so why not wait five years to vaccinate all dogs? Because some dogs are genetically non-responders. This means that their immune systems may not respond to the vaccine like normal dogs. If your dog has this defect, a titer will catch it and your veterinarian will know whether or not to vaccinate your dog.
In the end, veterinarians are about finding what is right for your individual pup — now and as she ages. Make sure to have these conversations with your veterinarian early so that he or she can plan the right vaccination schedule for your dog.
Dr. Lisa Radosta