Veterinary Practice News — March 2013
Change Language:
Vets Slowly Move To 3-Year Vaccine Protocols
Don Jergler

Vaccination guidelines for the dog and cat have been updated and the booster recommendations for core vaccines continue to be “every three years.” So what’s more appropriate—annual or triennial vaccination?

Except for rabies vaccine, veterinarians do have the discretion to recommend either annual or triennial administration of core vaccines. There’s no legal mandate that requires a veterinarian to follow the “every three years” recommendation.

“Basically, what we’re seeing is there’s a gradual trend toward three-year protocols,” said Mark Kimsey, DVM, senior brand manager for canine biological, with Boehringer Ingelheim Vetmedica Inc. of St. Joseph, Mo.

In the past, most veterinarians recommended core vaccinations every year for their patients, but more and more are coming over to the mindset that it’s fine to vaccinate once every three years for adult dogs, said Dr. Kimsey. Duration of immunity, or DOI, does not seem to be limited to one year.

“ About half of them use a threeyear protocol for canine core vaccines, about half of them use a oneyear protocol,” Kimsey said, adding that a growing number believe that core vaccines—against distemper, adenovirus, parvovirus and rabies for dogs, and for cats feline parvovirus, herpes virus, calicivirus and rabies–are providing enough immunity for three years.

Richard Ford, DVM, is co-author on both the American Animal Hospital Association canine vaccination task force and the American Association of Feline Practitioners feline vaccination advisory panel.

He agrees with Kimsey.

“It’s a slow change,” Dr. Ford said. “Most practices still recommend annual vaccinations. All the vet schools are teaching triennial vaccinations.”

While Ford believes that a lot of the dust has settled over the issue of extended vaccination intervals for dogs and cats, he figures, based on information from manufacturer sales reps, that 40 percent now recommend triennial vaccinations, and about 60 percent still recommend annual vaccination.

“When we introduced recommendations through the canine and feline guidelines that the core booster vaccines could be administered to healthy dogs and cats every three years, or longer, without risk of loss of protective immunity, practicing veterinarians really sat up and took notice,” said Ford, an emeritus profession of medicine at North Carolina State University.

“Some acknowledged the reality and changed their protocols, while others, fearing loss of a major source of revenue, argued against anything other than the time-honored paradigm: annual boosters.”

Vet Visits

Gary D. Norsworthy, DVM, owner of Alamo Feline Health Center in San Antonio, is among Ford’s 60 percent. He has worked in the field for 40 years.

Dr. Norsworthy acknowledged that vaccine protocols continue to be controversial, with newer veterinary school graduates more often pushing their employers to adopt triennial protocols.

But he noted that a substantial number of clients present their cats for wellness examination only if they believe vaccines are needed.

In fact, according to the Bayer veterinary care usage study published in 2011, “Many pet owners primarily associated veterinary care with vaccinations. Because many pets did not require annual vaccinations, pet owners, especially cat owners, visited their veterinarian less often.”

The findings were part of the larger study, which offered reasons for declining vet visits.

“I am determined not to lose my opportunity to do annual wellness exams,” Norsworthy said. “I believe that I can save far more lives by doing this than by any other proactive method. Consequently, I continue to use a rabies vaccine that is only approved for annual use, with a one-year duration of action. That allows me to tell my clients that I must see their cats annually.”

Internet chatter continues to scare cat owners into believing that vaccines are dangerous and can cause cancer or sarcomas, said Norsworthy, who sees from 75 to 100 cats a week.

“In spite of the fact that the incidence in my practice is 0.34 per 10,000 cats vaccinated–one sarcoma from over 65,000 doses of vaccine—I have more and more clients who either decline rabies vaccine or decline all vaccines,” he said. He notes that that “flies in the face of Texas law,” which mandates that cats be vaccinated either annually or triennially as determined by the duration of immunity of the vaccine used.

“Consequently, my practice vaccinated 25 percent fewer cats in 2012 compared to 2007.”

Ford has seen manufacturers respond to newer recommendations by developing and licensing a few “extended interval” vaccines.

“Largely, this seems to have been done as a marketing effort intended to appeal to practitioners who wanted to follow current guidelines but were concerned with product labeling that recommended ‘annual boosters,’” he said.

The point may become moot. The U.S. Department of Agriculture allows manufacturers to publish results of their vaccine DOI studies on the label of individual products, many of which last beyond three years. Yet the term “annual booster recommended” is still included in the text of the label for many products.

“I suspect that someday, the USDA will simply enable manufacturers to remove the ‘annual booster recommended’ wording from the package insert, publish their DOI data, and let practitioners decide what to use and how often,” Ford said.

While some new core vaccines have been introduced, the noncore market has seen few truly new developments, Ford said.

“In the category of non-core vaccines, we have recently seen a significant effort by manufacturers to modify existing vaccines rather than introduce truly new vaccines for protection against new or unique infectious disease threats,” he said.

Ford said canine influenza virus (CIV) vaccine was the last noncore vaccine for a truly new disease to reach the U.S. market.

The first CIV vaccine was licensed in 2009, and “current research and anecdotal reports from practicing veterinarians suggest that the incidence of CIV seems to have declined significantly over the past few years,” he said.

Social Trend

Anecdotally, at least, a growing number of dog parks, dog beaches and more communities are touting themselves as “pet friendly.” It’s a societal trend that could enable canines to become more social with one another.

And that’s a trend that Kimsey, of Boehringer Ingelheim, believes he’s seeing, one he believes could generate more need for a noncore vaccine for canine infectious respiratory disease, or Bordetella bronchiseptica— a condition also sometimes called kennel cough.

BIVI has a new vaccine called Bronchi-Shield Oral. Launched last April, the vaccine is given orally by being sprayed into the buccal cavity.

As more people take their dogs to dog parks, dog beaches, board-and-cares and kennels, those dogs are more frequently interacting with other dogs, he said.

The most recent canine guidelines were issued by AAHA in late 2011 and though they didn’t recommend biologics for canine infectious respiratory disease as a core vaccination, it is recommended for dogs at risk.

“Dogs that are going to dog parks regularly should have it,” Kimsey said. “I don’t think it’s enough of a trend yet to make it core, because not everybody is doing that. But veterinarians need to be thinking about what [activities] the client does with the dog, and then recommend vaccines based on that conversation.”

He said more vets are seeking alternatives to injections and intranasal vaccinations, which can agitate a patient and cause it to sneeze all over someone attempting a vaccination.

He said they don’t do that with Bronchi-Shield Oral.

“When you give it to them orally, they basically just lick their lips and they’re done.”

Whether the subject is core or noncore vaccines, practitioners’ taste for the topic seems to be insatiable.

Ford, a regular speaker at veterinary conferences, such as the Dr. Jack Walther 85th annual Western Veterinary Conference, which took place in February in Las Vegas, said crowds always pack any session on vaccination.

“It’s not unusual to have 500, 600 in a room,” he said, adding on the topic of vaccinating that “Veterinarians want to do it well. They want to do the right thing.”

Biologics manufacturers

Richard Ford, DVM, co-author on both the AAHA canine vaccination task force and the AAFP feline vaccination advisory panel, outlined some issues that are important to biologics manufacturers.

Facilitating efforts among veterinarians to improve vaccination compliance among pet owners is a top priority.

“Compliance among cat owners for routine health care is appalling,” said Ford, adding that practitioners are looking for help, and manufacturers are looking to help practitioners find ways to generate better compliance.

With so many vaccines available in a highly competitive market, vaccine pricing continues to be a major driver in vaccine sales and retaining brand loyalty.

“Today the profession benefits from remarkably low-cost vaccines,” Ford said.

Limiting adverse reactions is a topic of great importance to manufactures, Ford said.

“It’s my impression that vaccine reactions, especially acute adverse events such as pain at the time of injection, are among the most significant reasons veterinarians will switch brands,” he said. “Therefore, considerable effort and cost is being expended in mitigating vaccine reactions.”

Over the last 10 years, significant advances in vaccine technology for animal health have been introduced, particularly the modification of existing vaccines.

“There is a significant range of vaccine technologies, ranging from inactivated bacterial vaccines to virus-vectored recombinant and DNA plasmid expressed vaccines,” Ford said. “Educating veterinarians on the technology and the benefits that new technology offers patients is a factor of growing importance to the industry.

The vaccine pipeline has led to research into new vaccine technologies, enhanced immunogenicity and opportunities to introduce “therapeutic” vaccines.

“For example, efforts are under way to develop efficacious therapeutic vaccines for osteosarcoma and lymphoma,” Ford said. “Also, everyone is on the lookout for the next pandemic for which a new vaccine would enjoy widespread use.”