How often are Vaccinations Really
Needed?
The idea that over-vaccination cannot harm an animal has been proven false. Expert in immunology and veterinary pathology Dr. Ronald D. Schultz writes, in Duration of Immunity to Canine Vaccines: What We Know and Don’t Know, that “We have found that annual revaccination, with the vaccines that provide long-term immunity, provides no demonstrable benefit and may increase the risk for adverse reactions.” Our vaccination programs are gradually changing. The American Animal Hospital
Association updated the vaccination guidelines in 2011, but we may have further to travel.
In their 1970’s study Schultz and his colleagues demonstrated that certain vaccines are not needed as frequently due to the duration of immunity. He states that the three most important
viral infections are CDV, CPV-2 and CAV-1, and if a puppy is immunized with these vaccines, there is every reason to believe the animal will have life-long immunity. The vaccines mentioned above, plus the rabies vaccine, make up the “Canine Core
Vaccinations.” The rabies vaccination is mandated by law every three years, but the Seven Year Rabies Challenge Fund is underway to try to change the law to five-year and ultimately seven-year intervals, as serological studies have shown dogs’ antibody titer counts at levels that confer immunity for seven
years after vaccination. A titer, the measurement of antibodies in the system to a specific antigen, is an important tool in determining if a booster is needed or not.
Safer Vaccination
It is vital to protect young pets with the core vaccines. However, it is also important to keep your dog safe from incurring adverse reactions due to over-vaccination. There are steps to take if you
believe your animal is at risk for over-vaccination. Remember, more is not better, so before you revaccinate ask your vet to titer your pet. Low titers, however, may not necessarily mean the animal lacks the proper immunity.
Schultz states that if any antibodies are found, the dog in question is protected if older than 16 weeks of age. If you must revaccinate, discuss with the doctor the option of using a single antigen, or a “simpler” vaccine which has fewer vaccines in it than the multivalent vaccines which can be composed of as many as seven or more vaccines, often mixing “core” viral and “non-core” bacterial infections. Think about how hefty an amount that
is to inject into the blood stream at once. Also note that these single and “simpler” vaccines may be harder to come by. It is suggested that the best technique is to inject each different vaccine into different injection sites so that they are dispersed to
different lymph nodes.
Dr. Schultz, who also created the first veterinary clinical immunology laboratory in the US, has been instrumental in recommending today’s vaccination guidelines and ensuring they
are backed by scientific research. He states, “My general philosophy is to vaccinate more animals in the population, but vaccinate with only those vaccines that the animal needs, and only as often as needed to maintain proactive immunity.”
What about Non-Core Vaccinations?
Certain vaccines such as leptospirosis, Lyme, and bordetella, to name a few, are non-core, or optional. (There are an ever increasing number of non-core vaccines coming on the market.) For many of these, duration of immunity and efficacy is not known, and the risk vs. benefit is often not understood. Before consenting to these particular vaccines educate yourself about the complexities of each infection and its associated vaccine.
Although there is scientific evidence that points to dangers in over-vaccinating, doctors and pet owners alike typically opt for universal revaccination. Most pet lovers have not heard of the potential risk to the animal, which can be particularly problematic in instances of pregnancy, autoimmune disease, or immune-deficiency. There is a good case being made that vaccine programs should be custom-tailored to meet the needs of the particular animal. Veterinarians also note that in determining
the best course of action, it is important to take into consideration the dog’s lifestyle, geographic location, medical history, age, and health status.
As pet owners, we shouldn’t be afraid to ask questions of the veterinarian and to discuss any information that we have discovered. The decision about what vaccinations to give or not to give should be a conjoint one. Perhaps if your vet seems resistant to research and data presented, or will not listen to your desires, you should consider consulting with a veterinarian who respects your wishes and your desire for self-education. The more we discover through scientific exploration, the more accepted views change. It might be time to re-think the frequency of vaccinations.
By Sarah Zumhofe