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Should You Vaccinate Your Pet Every Year?
Analysis by Dr. Karen Shaw BeckerJune 26, 2022
STORY AT-A-GLANCE
- A few brave souls in the conventional veterinary community are working to encourage their colleagues to consider antibody titer testing in lieu of repeated re-vaccinations of cats and dogs, even though the World Small Animal Veterinary Association has supported the use of vaccine titers since 2013
- Pet parents frequently find themselves in lose-lose situations if they’re reluctant to automatically re-vaccinate and request vaccine antibody titer tests instead
- Titer tests can be performed to determine a dog’s immunity to distemper, parvovirus, and adenovirus; and a cat’s immunity to herpesvirus, calicivirus and panleukopenia; however, positive rabies titer tests are not “acceptable” proof of immunity under the law
- It’s important for pet parents to understand that while a positive titer always means a pet is carrying protective antibodies; a negative titer does NOT always mean a pet is vulnerable to disease
- Many pet parents don’t realize that vaccinations don’t always result in immunization (protection) — titer tests determine if an animal is protected or not
One of the workarounds to blindly revaccinating pets is vaccine antibody titer testing (aka doing "titers"), which has been endorsed by the World Small Animal Veterinary Association (WSAVA) since 2013,1 but is still not routinely recommended by most veterinarians.
Often times, pet owners who want to find out if their dog or cat has been adequately immunized prior to automatically re-vaccinating get pushback from veterinarians, including being told titers will cost up to 10 times as much as a vaccine. Thankfully, UW-Madison and The Healthy Dog Workshop are two of many institutions offering affordable titer testing these days.
Blood samples for titer testing can also be submitted through both Antech and Idexx national veterinary laboratories, but because the cost is much higher, many vets are opting to carry the much more affordable in-house VacciCheck® kits.
The hopeful news is that more and more vets in the conventional veterinary community who are beginning to realize this hardline approach to vaccinations against the wishes of clients is putting well-meaning pet parents in an impossible situation when it comes to their animals' health.
In addition, it leaves pet owners questioning the intentions of veterinarians who actively choose to run the risk of administering too many unnecessary vaccines rather than offering affordable titer tests to determine if their patients are already protected against disease thanks to an earlier vaccine.
A Positive Titer Test = A Protected Pet
One member of the veterinary community who has spoken out on this topic is Dr. Richard Ford, who encouraged attendees at the 2020 Midwest Veterinary Conference to stop thinking of the situation as vaccination vs. titer testing, and instead consider "using antibody testing to assess response to vaccines."2There are four core diseases for which a positive titer test can be considered a definitive indicator that the animal has protective immunity: distemper, parvovirus and adenovirus in dogs, and panleukopenia in cats (although many labs also now offer calicivirus and herpesvirus titer testing). Unfortunately, because rabies vaccines are required by law, a positive rabies titer test cannot be interpreted (under the law) as an indication of protective immunity.
The fact is that a positive rabies titer also indicates protective immunity, but existing laws require re-vaccination, regardless. This is a situation that must be addressed. Laws not based on scientific evidence force pet owners and veterinarians to repeatedly re-vaccinate animals who already have protective immunity against rabies. These re-vaccinations are not helpful (i.e., they don't make pets "more immune") and can be harmful to some animals.
Regarding the remaining core vaccines (which are not mandated by states, but may be required by grooming and boarding facilities), there are two types of titer tests available — quantitative and qualitative.
Quantitative titer tests are sent out to a laboratory and results are returned in a few days. The results are reported as a titer, for example, 1:1600, but the number isn't important as long as it's positive. An animal is either immune or not — a fact Ford emphasized with his audience, since many veterinarians scrutinize the numbers unnecessarily.
Qualitative titers are performed in veterinary clinics as point-of-care tests that provide results ("yes" = positive; "no" = negative) within about 25 minutes. These tests have been validated, and a positive result correlates well with the results of quantitative tests.
Negative Titers Don't Necessarily Signal Lack of Protection
When a titer test for one of the core diseases listed above produces a negative result, Ford cautions that veterinarians shouldn't assume an adult cat or dog who has been vaccinated in the past is not protected against that disease. According to the American Animal Hospital Association (AAHA) guidelines for dogs (which also reasonably apply to feline panleukopenia):3- A "negative" test result does not always correlate with susceptibility. Antibody may fall below detectable levels in the absence of exposure, including re-vaccination. For adult dogs which have been shown to have had protective titers against CDV, CPV and CAV2 in the past, exposure to pathogenic virus is likely to induce an immune "memory" response resulting in a rapid, anamnestic protection, even years following the last vaccination.
- A "negative" or "weak" response indicates that further vaccination may be of benefit to re-establish humoral response above the sterile immunity threshold.
- In effect, documentation that an individual patient has ever had a "positive" antibody test result for canine distemper, parvovirus, and/or adenovirus denotes that immune memory exists and the patient, if exposed, is expected to mount a rapid, protective response whether or not detectable levels of antibody were present at the time of the exposure.
- False negative test results are uncommon and can be associated with low test sensitivity, insufficient time following vaccination for a detectable antibody response to develop, procedural errors, etc.
Vaccination Doesn't Always Deliver Protection
Another extremely important point Ford reinforced in his presentation was that just because a pet is vaccinated (got the shot) doesn't mean he has been immunized against disease. The purpose of vaccines is to trigger an immune system response that confers immunity; when the animal makes adequate protective antibodies in response to the vaccines, then they're immunized.However, according to Ford, research shows that at 12 weeks, only 50% of puppies have been immunized against distemper and parvo, likely due to interference from maternal antibodies. That's the reason puppies (and kittens) receive a series of vaccines — so that at least one vaccine is given after maternal antibodies have disappeared.
Per Ford, at 16 weeks, 15% of puppies are still not immunized. Owners who need or want to know definitively that immunization has been achieved can ask for titer testing two to four weeks after completion of the vaccine series. This is a crucial step in determining whether your puppy is protected against parvo, distemper, and adenovirus, or not.
I have strongly advocated for more bio-individualized vaccine protocols for the last 20 years, including the use of vaccine nomographs to correctly time puppy vaccines. Dr. Ronald Schultz was the immunologist who introduced me to this invaluable tool in 1999 to assess when puppy vaccines are best administered. Titering pregnant dogs to determine when maternal antibodies will dwindle in her litter is a wise strategy to avoid unnecessary and ineffective inoculations.
By knowing when maternal antibodies wane, proactive wellness veterinarians don't have to guess at when to initiate effective puppy vaccines, we know. This easy and elegantly simple approach to accurate vaccine timing prevents the administration of unnecessary vaccines when the puppies are too young (and maternal antibodies are high) and offers litters the potential of avoiding ineffective vaccinations.
There's one situation all pet parents should be aware of, and that's the rare possibility their pet is a "non-responder." A small number of dogs are genetic non-responders to the parvovirus vaccine (but do respond to vaccines against other diseases).
These dogs will not produce antibodies, no matter how many times they are vaccinated, and are at high risk for parvo, especially as puppies, so it's extremely important to minimize their exposure to prevent infection.
The general recommendation for adult dogs with a negative titer — especially those with an unknown vaccine history — is to administer a booster, then titer two to four weeks later to see if the vaccine produced measurable antibodies.
However, the decision depends on several factors. For example, animals with a history of adverse vaccine reactions, an autoimmune disease, a chronic illness (including cancer), or who are taking immunosuppressant drugs should not be vaccinated at all, and instead should be automatically titered.
If you discover your dog is one of those rare "non-responders" you can read the AAHA's recommendations for managing negative titer results in common situations here (scroll down to the testing indications section), or work with your integrative veterinarian, who may prescribe homeopathic nosodes in these situations.
Additional Info on Titer Testing and Vaccines
These days it's not uncommon to be labeled an "anti-vaxxer" if you ask any questions about the number or frequency of vaccines your pet receives, which is unfortunate.In my opinion, Dr. Ford's suggestion to use titers to determine the necessity of additional vaccines makes guardians wise-vaxxers, not anti-vaxxers. I'm excited conventional veterinarians are being encouraged to participate in the much-needed conversation about titers that Dr. Ford is initiating in our profession.
If you're concerned about over-vaccinating your pet, I encourage you to view my interview with Dr. John Robb, founder of Protect the Pets, who is fighting the good fight to keep animal companions safe from too many unnecessary vaccines, and one-size-fits-all vaccine dosing. Our collective goal is to have all pets immunized without being over-vaccinated.
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