What Is Immunocontraception?

As immunocontraception will no doubt come up as a method of keeping the white deer population in check in Seneca Falls, NY, we thank Dr. Priscilla Cohn for giving us permission to reprint the following letter by the world renowned scientist in immunocontraception, Dr. Jay Kirkpatrick. It was written in response to a letter by the Pennsylvania Game Commission in which they criticized the “sterilization” of deer. The letter appeared in the Bucks County Courier Times written by Jerry Feaser, Press Secy.

Due to space limitations, we are printing excerpts. For the full article, please visit www.pzpinfo.org

I shall respond…(to Feaser’s letter on “sterilization.” ) That said, or written, please keep in mind that journalism regarding this subject has been, for a decade or more, embarrassingly shabby, inaccurate and misleading and for the most part reflects a lot of passionate opinions and theories but little of factual substance.

At the outset, I would like to make two points clear. First, I do not advocate the use of contraception for deer, at Tyler Park or anywhere else. I merely convey facts, data, and scientifically-supported conclusions. Urban and suburban deer problems are local issues and it is not my domain to advocate any management approach outside my home city here in Billings. The Tyler deer are someone else’s deer and someone else is responsible for decisions about their management. Second, I do not deal in opinions. I deal only in facts, derived from controlled studies, appropriate analysis and peer-reviewed published data. With that stated, let’s examine the article’s salient points.

To begin with, “sterilization” is an inaccurate and misleading term. Contraception, which is what the debate is all about, is reversible fertility inhibition, but not sterilization. Spaying is sterilization; neutering is sterilization, but condoms, pills, diaphragms, IUDs, and immunocontraception (vaccines) are reversible and by definition, contraception. The paper’s editors, and both authors should be more careful about their use of inaccurate terms.

Mr. Feaser’s letter is a masterpiece of hyperbole, misinformation and dissembling. First, he makes no distinction between urban/suburban deer and rural deer and the contraceptive technology, which was developed only for deer herds where traditional management methods are not deemed legal, wise, safe or publicly acceptable. The failure to make this clear at the outset pits the hunting community against the broad concept of management by contraception.

…Let’s examine the safety issue just a little bit more. The vaccine has been used on the wild horses of Assateague Island National Seashore, in Maryland, for 18 years now, and what safety issues have arisen? Well, first, the body condition scores of the population have increased significantly (see Turner and Kirkpatrick. 2002. Reproduction. (Suppl. 60):187-195), mortality has decreased significantly (same paper), the vaccine has proven to be safe to give to pregnant animals (see Kirkpatrick et al. 1991. J. Reprod. Fert. (Suppl. 44) 321-325), doesn’t cause changes in seasonal birth patterns or the health of foals born to treated mothers (see Kirklpatrick et al. J. Appl. Anim. Welfare Sci. 6:301-308) and has extended the longevity of the treated horses by more than 10 years (see Kirkpatrick and Turner 2002. J. Reprod. Fert. (Suppl. 60): 197-202; Kirkpatrick and Turner 2007. Zoo Biol. 25:1-8), nor have any behavioral changes been noted (see Powell 1999. J. Appl. Anim. Welfare Sci. 2:321-335) nor have there been any deleterious physiological changes regarding the ovary or endocrine system (see Kirkpatrick et al. 1995. Biol. Reprod. Monograph Series I: Equine Reproduction VI: 411-418; Powell and Monfort 2001. J. Appl. Anim. Welfare Sci. 4:271-284) I could go on, and cite dozens of other papers regarding the use and safety of this vaccine in other species (some 50 of them, including a lot of primates) but I think the point is made. Finally, the vaccine is a protein and ninth grade biology students who are paying attention in class know that proteins can’t pass through the food chain. Does this all sound unsafe?

Next. Mr. Feaser tackles the economic dimensions of deer contraception. He quotes a figure of $1,000 per deer. The cost of the vaccine is $21/dose (we, by law, must provide it at our cost of production, with no profit), the dart costs about $1.50, and the bulk of the labor to do the darting is where the real cost lies. Costs will vary from site to site, depending on who is doing the work and what they are paid. If you want to pay someone $80,000 a year to dart deer, the cost will be high; if you want to use trained volunteers the cost is less; if you use employees already employed by a park, or agency, or whatever, the cost is somewhere between. I actually can’t say what the costs would be in any given site because of these variables, but I kept the books for the first two years of the Fire Island project and the costs never exceeded $10,000. That included a two or three air fares from Ohio and Montana to New York, and we treated about 150 deer. My math shows that to come out to about $66/deer. I wonder who estimated the $1,000 per deer.

Now Mr. Feaser goes on to say that “Research also suggests that the use of hunting alone or in combination with other management actions, may be the only way to effectively reduce free-ranging deer populations”. If Mr. Feaser is talking about the deer in Potter County, or even all of Bucks County, I might agree, but we are not talking about the deer in Potter County or all of Bucks County. We are still talking about discrete urban/suburban deer populations. This is one more attempt to confuse the issues. And, if Mr. Feaser bothers to read the papers cited above, he knows that his statement is not factual. He closes with descriptions of deer contraception as unproven (not accurate- see above), experimental (true, see above) and cost prohibitive (not accurate, see above).

I am not dismayed by the passion that accompanies this subject, nor am I dismayed if a community chooses not to use contraception. That is local business and not mine. What does upset me, is knowingly manipulating information, hyperbole, attempts to frighten people with skewed information and an anti-intellectual approach to debates that excludes facts and data and substitute opinion. Does any of that sound familiar on a larger scale? Incidentally, lest anyone attempts to pigeonhole me in some social activist group, I have hunted deer for most of my life and I started in Bucks County more than 50 years ago.

Jay F. Kirkpatrick, Ph.D., Director, The Science and Conservation Center, 2100 South Shiloh Road Billings, MT 59106, 406-652-9719.


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