Contraceptive vaccine under study for elephants and horses

Editor’s note: Kayla Harr is a junior in English.

The first lesson the elephants taught Ursula Bechert was that they had a sense of humor.

On her first day at the Wildlife Safari in Winston, Oregon, Bechert got soaked as she gave the animals their daily shower. The next day, she came to work wearing rubber boots, hoping to at least keep her feet dry. Noticing Bechert’s change in apparel, an elephant named Alice quietly drew water into her trunk while Bechert washed another elephant, slipped it into one of Bechert’s boots, and filled it with water.

Ursula Bechert, left, worked with elephants at the Oregon Zoo in 2000 (photo courtesy of Ursula Bechert)

“I swear she had the biggest grin on her face,” Bechert says, remembering Alice’s mischievous nature.

Bechert, director of Off-Campus Programs in Oregon State University’s College of Science, has spent much of her life in the company of animals. After fulfilling her childhood dream of becoming a veterinarian and working in small animal practice, she returned to school to earn a doctorate in reproductive endocrinology and completed her thesis while working with elephants at the Wildlife Safari, a nonprofit zoological park.

Driven by a passion for conservation, Bechert has worked with elephants and other species to manage animal populations and find effective solutions for conflicts that arise between humans and animals. Recently, she has been studying the effects of a new form of an immunocontraceptive vaccine known as porcine zona pellucida (pZP) in elephants and wild horses. The vaccine may help reduce conflicts by keeping animal populations in check. Her early results suggest that this new vaccine formulation may be an important tool to alleviate tensions caused by other controversial methods of population management.

“Originally, I wanted to help individual animals as a veterinarian,” Bechert says. “Through research, I realized I could impact entire populations. By working on population management tools like contraception, I now hope to help sustain animal populations in the wild. I don’t believe that we will have succeeded in saving a species if those animals only survive in captivity; we need diversity of species for healthy ecosystems.”

One Shot, 10 Years

To prevent conception in animals, pZP vaccines produce antibodies that block sperm from attaching to unfertilized eggs. While pZP vaccines have been used in the past to manage elephant and horse populations, the vaccine Bechert is working with is a unique formulation called SpayVac®.

In northern Botswana in 2003, Bechert and a team of researchers applied tracking collars to elephants. Scientists observed that after landmines were removed in Angola, elephants resumed migration through areas they had avoided during the civil war. Understanding elephant movements and habitat use can help minimize human-elephant conflict. (Photo: David Rogers)
In northern Botswana in 2003, Bechert and a team of researchers applied tracking collars to elephants. Scientists observed that after landmines were removed in Angola, elephants resumed migration through areas they had avoided during the civil war. Understanding elephant movements and habitat use can help minimize human-elephant conflict. (Photo: David Rogers)

Produced by Canada-based ImmunoVaccine Technologies Inc., SpayVac® has the potential to act as a multi-year contraceptive. Other pZP vaccinations require a booster four weeks after the initial injection and must be administered annually to remain effective, which Bechert says is more expensive and stressful for handlers and animals. A single shot of SpayVac®, however, has been demonstrated to be effective in other animal species for up to 10 years.

Bechert began working with SpayVac six years ago when she studied the vaccine’s effect on captive elephants in North America. As viable habitat and resources become more limited in many African and Asian countries, Bechert says, the incidence of human-elephant conflict increases, necessitating elephant population control.

“They’re competing over common resources like water,” Bechert says. “Some villages try to keep elephants out by creating biological barriers with chili peppers elephants don’t like.”

Managing elephant populations with a multi-year contraceptive could help reduce the number of confrontations and the need to cull elephants to control their populations, Bechert says. So far, SpayVac® has shown promise because pZP antibody concentrations have remained high in the elephants that were vaccinated, indicating that the vaccine is still active.

Through her research on SpayVac®, Bechert is working to find a solution to human-animal conflicts in the United States as well.

Wild Horses

In a recent study funded by the United States Geological Survey (USGS), Bechert led a team of OSU researchers in assessing the safety of SpayVac® for use in horses. Like elephants, wild horse populations are exceeding the carrying capacity of the land they inhabit. Horses roam freely in the western U.S. and have generated controversy as cattle ranchers feel they must compete with wild horses for land and forage for their cattle. Addressing the problem has been difficult because land managers, cattle ranchers and horse lovers disagree about how growing horse populations should be managed.

Wild horses on Bureau of Land Management range near Burns in southeastern Oregon (Photo courtesy of the Bureau of Land Management)

The federal Bureau of Land Management (BLM) oversees management of horse populations and is struggling to find solutions that are effective and humane, Bechert says. Other methods of managing the wild horse population, which exceeded the BLM’s optimum management level by nearly 12,000 horses as of February 2011, include BLM roundups that capture and maintain horses in captivity or adopt them to individuals. Such activities, Bechert says, are an expensive and temporary solution to the horse overpopulation problem.

Just as Bechert believes SpayVac® could ease the tension between humans and elephants on the other side of the globe, she says the vaccine may be the best way to alleviate the competition between ranchers and horses over land resources in the U.S.

Starting in the spring of 2010, Bechert and a team of OSU researchers conducted a trial to determine whether SpayVac® could be effectively and safely used in horses. The study was completed last fall. While Bechert is currently in the process of publishing the results, she says their preliminary findings demonstrate no adverse effects to the general health of horses that received the vaccine, and results were promising.

In response to Bechert’s findings, the USGS began a five-year study of 90 mares in the spring of 2011 to observe the long-term effects of the contraceptive vaccine. While this study progresses, Bechert plans to publish the results of her work and apply for funding to support additional research on how the vaccine affects the horses’ ovaries and determine whether it is reversible. Understanding how the vaccine works and whether it can be reversed, she says, is important to effectively incorporating it as an effective management tool. If the USGS study goes well, Bechert says the BLM will likely begin to administer the vaccine in wild horse populations within the next five years.

Wild horses in a trap at the Warm Springs Herd Management Area near Burns in southeastern Oregon. (Photo courtesy of the Bureau of Land Management)

“I think this vaccine will do a lot to reduce human-animal conflict,” Bechert says. “Administration is easy and the vaccine is much more cost effective compared to other methods or products being used. I’m passionate about it for the animals, because from their perspective, getting one shot is much less stressful and easier than being rounded up and adopted or maintained by the BLM. I think SpayVac® will make a wonderful population management tool, and that really motivates me.”

1 Comment

Hi There, Congratulations on your discovery of the SpayVac. Hopefully it all goes well for the benefit of the animals.

If you don’t mind I would like to ask a question. In managing horses I have seen a herd attacked by a cougar, the stallion tried to protect the herd and when it got too difficult he chose a young mare (whom we have assumed to be baron) to feed/distract the cougar while he took the rest of the herd to safety. The mare did survive the attack for a few days, and it was after looking through her records of never having a foal that led us to believe that was why she was chosen.

If you vaccinate a bunch of animals the herds will discover the effects which could cause ostracism and/or depression in wild animals. How would you account for this possibility?

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