Titers Join Debate On Vaccine Frequency
For clients, vaccines are part of routine pet care and for the most part, veterinarians can expect owners to comply with vaccine reminders and schedule an appointment.
While the visit serves as an opportunity to examine the pet for other maladies, one thing is certain: The pet will be vaccinated before it leaves.
Some veterinarians maintain that administering core vaccines every three years or even annually is outdated and isn’t practicing good medicine. While practitioners argue that liability or a patient contracting a virus outweighs the risk of a potential vaccine reaction, critics interject the titer argument.
“Few veterinarians are proactive about discussing the options clients have in protecting their pets against disease,” says W. Jean Dodds, DVM, founder of Hemopet, a non-profit veterinary blood bank in Garden Grove, Calif. “The industry promotes more vaccines and veterinarians feel comfortable telling clients they’re necessary. Often, technicians have vaccines prepared before the doctor even examines the animal. Many vets don’t know how to handle titers or don’t want to bother with them.”
Vaccine experts liken the three-year protocol to that of children’s vaccine regimens, which have come under public scrutiny after accusations that they cause autism. Although all veterinarians agree vaccines are necessary, the frequency in which they’re given is debated.
“Veterinarians need to administer the rabies vaccine as defined by law, but other core vaccines for canine distemper virus, parvovirus and canine adenovirus-2, are administered needlessly,” says Ronald D. Schultz, DVM, PhD, Dipl. ACVIM, professor and chairman of the pathobiological sciences department at the University of Wisconsin, Madison’s School of Veterinary Medicine.
“Challenge tests and titer levels have shown animals to have strong immunity to these viruses five, seven, even 10 years after the vaccine was given,” Dr. Schultz says. “Animals died of old age before they needed to be revaccinated in those studies.”
Schultz participated in the vaccine task force that created the American Animal Hospital Assn. guidelines. AAHA canine vaccine guidelines make suggestions on titers and also say to vaccinate “no more than every three years” with core vaccines.
Schultz says veterinarians often read this as meaning the vaccines should be given every three years without question. Additional concern revolves around the physical condition an animal presents in and is still given vaccines as usual.
“Practitioners often don’t understand the value of titers and therefore don’t relay that to the client,” Schultz says.
“Also, titers are too expensive for most clients. Titers aren’t necessary for all vaccines, just distemper and parvo. Vaccines given annually for diseases such as leptospirosis and kennel cough should actually be given more frequently (at least annually) because they’re not as powerful as the core vaccines. Distemper, parvo (canine and feline) and adenovirus have 99 percent effective immunity and caliciviris and herpes virus vaccine have 60-70 percent effective immunity. Many of the animals given those core vaccines will have a lifetime of immunity.”
While drug manufacturers say they don’t disapprove of titer testing, they’re leaving the promotion of the procedure up to vets and predict the higher cost of titer testing opposed to vaccinating will discourage clients from agreeing to a titer test.
“A small portion of the population may have a reaction at the injection site or an anaphylactic reaction,” says Tom Lenz, DVM, vice president of professional services at Fort Dodge Animal Health of Overland Park, Kan.
“Vaccines are pretty accurate the way they’re labeled. These reactions have nothing to do with the frequency as to which the vaccines are given. Only about 50 percent of the animal population is vaccinated, for many reasons, one of which is cost. Clients won’t likely be interested in paying maybe three times as much for a titer.”
Dr. Dodds questions why pet vaccines are given with such frequency when vaccines for measles and polio aren’t given to adults.
“Instead of sending reminder cards for vaccines, veterinarians should be sending annual wellness exam reminders,” Dodds says.
“When vaccines are needed, they shouldn’t be given at the same site or at the same exam. Banfield Animal Health released two papers on this topic saying animals weighing less than 20 pounds and receiving combo vaccines are at the highest risk of vaccine reaction, yet few DVMs arrange separate visits as a precaution.”
Others say reducing vaccines to less than a three-year frequency would raise more questions about outbreaks of currently tamed viruses.
“People tend to forget that infectious diseases like distemper, parvovirus and others are deadly for those dogs that are not protected against them,” says Ulrike McCray, DVM, marketing director for companion animal health at Schering-Plough Animal Health.
“While these infectious diseases are rare among dogs and cats, it’s because they’ve been vaccinated,” Dr. McCray says. “If we reduce vaccinations in dogs and cats, the infectious diseases will return. Antibody titers are not always a reliable indicator for the level of protection necessary for a dog or cat; it’s more reliable to follow the recommendations of the label.”
On the Horizon
Schultz and a veterinary diagnostic company are designing a user-friendly titer test that could be used in-house, giving fast results and costing less than current testing methods.
“We project a 2010 release of the titer test, but it still must gain USDA approval,” Schultz says. “We hope the test will be used instead of immediately revaccinating an animal, but it wouldn’t need to be performed more often than every three years, or every five years.
There’s no reason to go from over-vaccinating to over-testing, although no adverse effects would come from drawing blood.”
Vaccinating less often is a concept trying to gain momentum, but it has been a concern to some for decades.
“It can be scientifically proven that not vaccinating can cause harm to an animal, but vaccinating per label suggestion has not been shown to be harmful,” Lenz adds. “Considering an animal’s likelihood of exposure, age, health and breed are some things veterinarians should consider before giving vaccines. I think some vets are very good at doing this while others are not.”
Dodds disagrees, saying just about anything can go wrong when a vaccine is given, from lethargy to death.
In a 2000 paper published in JAVMA, Dodds documented 1,400 cases in which more than 97 percent of the dogs tested had good immunity from vaccines given 10 years earlier.
“Vaccines are largely safe, and are intended to improve the health and welfare of animals,” Schultz says. “But when problems do occur and the animal didn’t even need the vaccine, that’s unacceptable. I would like to see more puppies and kittens vaccinated with the core vaccines because there are many that never get vaccinated. However, I would also like to see those that get vaccinated not receive core vaccines more often than is necessary and to only receive those non-core vaccines that provide a benefit.” <HOME>
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