By Dr. Becker
Recently I ran across two veterinary industry journal articles on vaccine titer tests that were a study in contrasts. The first article was headlined “Tough talks on titers” and echoed the traditional veterinary viewpoint on antibody titer tests:
“If a titer is low for a particular virus or bacteria, we can’t be certain that pet is actually immune. So most veterinarians recommend boostering vaccination if a titer is low.
Titers can have a place in veterinary medicine. However, we tell clients that they can be challenging to interpret, and the rewards of boostering a vaccination outweigh the risks.”1
Needless to say, I absolutely do not agree that over-vaccinating is preferable to accepting a low titer as evidence an animal is protected against disease — more about that in a bit.
For those of you who may be unfamiliar with titer tests, they’re blood samples that measure a pet’s level of antibodies against infectious agents such as the distemper virus, parvovirus, hepatitis and others. The presence of antibodies against a disease means the animal is protected from that disease.
The antibody level is a reflection of both the animal’s natural exposure to the infectious agent, and the vaccinations he’s received.
Conventional Veterinarian Advocates Titers, Not Boosters
The second article was refreshingly headlined “Titer talk: An alternative to annual vaccinations.” The subhead was even more encouraging: “Veterinarian advocates testing immune response rather than giving vaccine unnecessarily.”
The veterinarian is Dr. Jeff Werber of Century Veterinary Group in Los Angeles. I checked out his website, and while his clinic offers a couple of alternative treatments (acupuncture and laser therapy), it appears to be primarily a traditional veterinary practice.
According to the article, Werber “… questions the necessity of repeated vaccination over the life of an animal when research indicates that at least some vaccines confer long-term immunity.”2 At his practice, Werber recommends titer testing instead of automatic vaccination.
He charges just $50 for a titer test, which is very reasonable compared to what many clinics charge, and if the test shows the pet is unprotected, he gives the vaccination for free. His clients, especially those concerned about over-vaccinating love this approach.
Werber says in the 20 years he’s been titering, he’s never had a pet with a positive titer acquire a disease. Predictably, he gets quite a bit of push back from the traditional veterinary community, but he’s confident, and I am as well, that titer testing errs on the side of patient safety.
Because he charges $50 for titer testing and $20 for a vaccination, some of Werber’s colleagues have even accused him of doing it for the money. “But that’s not really what this is about,” he says. “If you recommend what you believe in and treat clients right, they’re going to do what’s best for their pets.”3
In contrast, I would suggest that conventional veterinarians who try to talk their clients out of titers in favor of giving an unnecessary booster (with a 400 percent-plus markup price tag) could be guilty of just trying to make a quick buck.
Yes, titers are much more expensive than a dollar dose of vaccine, but the immunologic protection you’re providing an already-immunized pet could be lifesaving.
Here’s hoping Werber’s approach to vaccinating pets catches on with more of his colleagues in the conventional veterinary community. I’m encouraged that his advocacy of titering is featured in a mainstream veterinary industry publication.
Vaccination ‘Expiration Dates’
Certain vaccinations (what we call the “core” vaccines), including those against distemper, parvo and hepatitis in dogs, and panleukopenia in cats, produce sterile immunity. Sterile immunity is long-lasting — a minimum of seven to nine years, to a maximum of lifetime immunity — as measured by titer tests.
This means your dog or cat cannot become infected, nor will he shed the virus should he be exposed.
It’s important to note that immunization is the outcome of proper vaccination. The act of administering a vaccine doesn’t necessarily mean the animal has been immunized against the disease.
Other types of vaccines (the “non-cores”) do not produce sterile immunity. These include vaccines against Lyme disease, leptospirosis, bordetella and other upper respiratory/kennel cough-type viruses, as well as canine influenza. These vaccines don’t last long — typically seven months to a year.
The antibody levels against these diseases, as measured by titer tests, fall off with each successive year. However, in addition to antibodies, animals also have what we call immune memory cells against disease, and they remain for a lifetime.
Thanks to these immune memory cells (which cannot be titered for), a low titer against one of the non-core diseases doesn’t necessarily mean the pet is no longer protected. She may still be protected for up to a year or much longer by immune memory cells.
We can reasonably compare the dog and cat core vaccines to the human polio vaccine, or even vaccines against measles, mumps and rubella (the MMR vaccine), which provide lifetime immunity. Non-core veterinary vaccines can be compared to the human tetanus vaccine, which may not last for a lifetime.
The Question of Low Titers, and My Recommendations
As the first article I quoted above demonstrates, most conventional veterinarians recommend boostering (re-vaccinating) when any titer test for any disease returns a low result.
Admittedly titer test results can be confusing to interpret, but this is not the approach of most vaccine experts or holistic/integrative veterinarians (including me).
Veterinary vaccine expert Dr. Jean Dodds, who owns Hemolife, a veterinary diagnostic lab, uses the ELISA (enzyme-linked immunosorbent assay) antibody titer test. If she gets a negative on a test, she sends the sample out for an IFA (immunofluorescence antibody) confirmation test.
She provides both sets of test results to the animal’s veterinarian so he or she can use professional judgment and case history to decide whether or not to re-vaccinate. Dodds discourages veterinarians from giving combination vaccines and instead recommends single-agent vaccines, which are significantly less stressful to the body immunologically.
Dr. Ronald Schultz, a pioneer and expert in the field of veterinary vaccines, believes the specific titer numbers that diagnostic labs report are irrelevant as long as they’re positive, which indicates the presence of an immune response. According to Schultz, any measurable titer means the immune system responded.
If, for example, a gold standard test for distemper returns a level as low as 4 or as high as 64, it means the animal's immune system has developed antibodies. It is primed. If the dog is exposed to distemper and the virus isn't immediately neutralized, there will be a secondary memory response and he will be protected. Some labs recommend re-vaccination when a titer is present, but low. This is not what Schultz recommends, nor do I.
If a titer test for immunity against a core disease shows any level of antibodies present, I consider the animal protected and I do not re-vaccinate. If the titer test is negative, I give a single-agent booster for only the disease for which there are no measureable antibodies.
I don’t recommend non-core vaccines because they’re often not all that effective, they’re not long-lasting and in many cases they’re not even necessary depending on where the pet lives and his or her lifestyle.