Made To Order

Autogenous or custom — whatever you want to call them — mention this class of livestock vaccines in the right (or wrong) circles, and you're likely to draw a scowl. You might conjure up images of bubbling goo in a dirty bathtub, or a miracle cure for every bug that finds its way into a herd of livestock. Neither could be more incorrect.

More than likely, though, you'll get a quizzical squint — as in, “Just what the heck are you talking about?” Truth is, these much-misunderstood vaccines are beginning to come of age in the beef cattle industry.

Typically, custom vaccines are used when no commercial product is available for a new or unique disease-causing agent. They're made from viruses or bacteria found on the ranch or in the feedyard and isolated in conjunction with a disease. In most cases, USDA regulations restrict the use of the vaccine to a single herd or location with time limits on its use.

The custom vaccine industry was modernized in 1985 when amendments to the Virus-Serum-Toxin Act allowed the interstate licensing of autogenous veterinary products.

Custom vaccines soon thereafter hit their stride in the swine industry. The custom vaccine concept fit well with intensive swine systems in which disease problems are often unique to a particular hog operation.

“Autogenous vaccines haven't been used as vigorously and effectively in beef and dairy as they have in swine,” says Bill Kvasnicka, University of Nevada-Reno Extension veterinarian. “That's mainly because there have been so many commercial vaccines available to us.”

He admits custom vaccines have a sordid history. Many custom vaccines failed because the correct organisms weren't used, the manufacturers lacked good adjuvants and/or livestock producers misused the end product. But there's general agreement that today's custom vaccines can contribute to good veterinary medicine.

“If you can nail down the cause of the disease with an accurate diagnosis, and if there isn't a vaccine available, an autogenous laboratory may provide you with some help,” explains Kvasnicka.

Diagnostics Are Paramount

Leon Mills, DVM, Herington, KS, is a consulting feedyard vet who's been using custom vaccines for several years.

“Good basic diagnostic work is essential, and the proper adjuvant is critical to making a custom vaccine,” says Mills. “They certainly have their place in beef production, especially when you look at what it would take to develop a commercial vaccine for every type and strain of pathogen out there.”

He adds that the cost of treating sick animals and performance losses due to morbidity make it more important than ever that beef producers have the custom option.

A commercial vaccine product must be tested against a challenge model of the pathogenic organism to prove it protects against disease, while no efficacy studies are typically done on custom vaccines. But Mills is comfortable with the field performance of most custom vaccines. He makes sure that his clients keep their eyes open, though.

“The cowboys and feedyard managers are the ones who can really tell if a vaccine, any vaccine, is working,” he explains. “And they need to let me know if they see any adverse reactions or signs of problems.”

There's general (but not universal) agreement that because commercial vaccines are tested for efficacy, they are usually superior to custom vaccines.

“The lack of efficacy testing is a downside to the use of autogenous vaccines,” says Chris Chase, a veterinary microbiologist at South Dakota State University. “Just because a vaccine contains an organism doesn't mean it will elicit protection.”

Efficacy is one thing, but safety is a whole other issue. Chase is adamant that the development of a safe custom vaccine must be rooted in science. He recommends prospective clients thoroughly check out custom vaccine manufacturers to make sure they follow the same quality control and product assurance standards as commercial labs.

“Then the offending organism needs to be identified, as well as any production or management problems associated with the disease,” he says. “If a commercial vaccine isn't available, and the veterinarian feels it's in order, an autogenous vaccine manufacturer should be contacted for pricing and ordering requirements.”

While a commercial vaccine company can now request rapid development of a vaccine from USDA, Chase says custom vaccines can be produced more quickly. But, he says, don't look at custom vaccines as a miracle cure.

“I've seen where autogenous products were looked to as a last resort for problems that could be corrected by management changes outside of vaccination,” he says. “With autogenous vaccines it's even more important to emphasize that we can't be looking for solutions out of a bottle.”

Harold Vonderfecht, Plattsmouth, NE, is a field consultant for Fort Dodge Animal Health. As a veterinarian working in vaccine development for more than 30 years, he never thought he'd admit there's a place for custom vaccines.

“There was a time when I thought they were garbage,” he says. “There were too many labs out there without the technology and expertise to produce safe, pure and effective vaccines.”

But Vonderfecht says custom vaccine manufactures have “cleaned up their act” over the past 20 years. He's adamant, however, that the attending vet should routinely take specimens from the herd to see if there are any new isolates.

“Pick your lab carefully and especially look at their experience in diagnostics and the type of adjuvant they use,” he says. “There aren't many that have a lot of experience in the beef end of the business.”

In A Different Arena

Like it or not, the evolution of the beef industry toward more consolidation and integration is a force behind increasing use of custom vaccines.

“Whenever we bring larger groups of animals together, we're driving disease organisms more aggressively,” says Gary Anderson, PhD, Bucyrus, KS. He's a director of Novartis Animal Vaccines Inc.

“We're opening ourselves to a lot more opportunity for those animals to develop new diseases or new strains that can escape commercial vaccines and antibiotics,” he says.

The best place for a producer to start when considering a custom vaccine is a good diagnostic workup, Anderson echoes. He estimates that 50-60% of the disease isolates coming into his facility are from outside diagnostic labs.

“The rest are isolated in-house, and we are continuing to increase our diagnostic capabilities,” he says. “Technology and our knowledge of the immune system keep improving.”

In the past, the major concern was with the microorganism, and the adjuvant was an afterthought. But today, improved adjuvants are being used to not only make weak vaccines more effective, but to make custom vaccines further fit a particular disease-fighting regimen.

“Clearly our ability to generate custom vaccines is in a different arena now because of the adjuvants available,” says Anderson.

Beyond having better tools to work with, there's a change in the working atmosphere, Anderson says.

“The veterinary profession is becoming more specialized, and we're training our graduates to be more focused,” he says. “That allows them to ask more questions and dig deeper into problems — making them better vets in their specific fields.”

Anderson says this drives every other segment of the animal health industry to work harder and smarter and to use the science and technology at hand to answer the hard questions of animal health.

The Regulatory Story

The biologics industry was split on the issue of autogenous vaccines after 1985. That's when the Virus-Serum-Toxin Act was amended, requiring small vaccine laboratories to be licensed by USDA, says David Espeseth, Perkasie, PA. He's former director of licensing and policy development for USDA's Animal and Plant Health Inspection Service (APHIS) and current chair of the U.S. Animal Health Association (USAHA) committee on biologics and biotechnology.

“Early on, the larger companies raised questions about the licensing and compliance programs covering the manufacture of autogenous products,” says Espeseth. “The USAHA felt, though, that the regulations provide livestock producers the needed assurances of quality and have permitted development of autogenous products at realistic prices.”

Espeseth adds that with the availability of autogenous products, there's less motivation to use unlicensed biologics prepared in unlicensed facilities.

He says autogenous products fit well with small companies that have a close relationship with veterinarians who can provide personal service to their clients.

“Autogenous vaccines also offer a first line of defense against emerging diseases and help allow a timely response to emergency disease situations,” he says.

Espeseth is confident there's a balance between too restrictive controls that could make some products unavailable and regulations tight enough to keep unsafe biologics from getting into the hands of producers.

“We certainly have seen no instances of significant animal health problems or substantial economic losses from the use of autogenous products,” says Espeseth. “This says to me that the current regulatory framework is working.”

The science behind autogenous biologics is also working to produce better and safer products.

“There are still people who hold strong opinions on both sides of the autogenous issue,” Espeseth concludes. “But more and more the industry is that recognizing the restrained use of autogenous biologics has a place and a purpose in the livestock industry.”

Steps In Building An Autogenous Or Custom Vaccine

• The veterinarian and the producer must recognize an infectious disease in the herd.

• The veterinarian collects tissue and/or blood samples from the infected animals.

• Samples are sent to a government or commercial diagnostic lab for isolation.

• The diagnostic lab transfers the antigen to a licensed biological manufacturer.

• Disease organisms are grown to produce the necessary amount of vaccine and then inactivated to ensure that they are dead.

• The vaccine is blended with an appropriate adjuvant, bottled and labeled.

• The product undergoes safety and quality testing before being shipped to the vet.

• Depending on the organism, it generally takes two to eight weeks from beginning to end to produce the custom vaccine.

• The vaccine may be archived for up to two years for future use.