Does PZP result in wild herds with lower immune systems and potential for die-offs?

PM Tule Elk Males FIghting by austlee

PZP is an immunocontraceptive and pesticide which causes an immune reaction to reject fertilization, while the females still come into estrus. Besides wrecking havoc on the immune system, injecting herds with PZP results in more fighting between males and many other behavior abnormalities.

Tule elk in Pt. Ryes National Seashore (Marin County, California) were part of a PZP (Porcine Zona Pellucida) experiment. Several years later there was a strange die-off.

Wildlife groups blamed park service management for leaving the elk fenced in during a drought–claiming that was the reason for the die-off.

Park service officials said the tule elk had water during the die-off.

“Some wildlife advocates have termed the situation a “die-off” and accuse the park service of allowing the elk to perish behind the fence that prevents them from finding enough food and water. Park service officials have a different view of what caused the population drop, and are hoping that new data will help address these concerns, especially as visitor interest peaks during the fall rutting season.” from: https://baynature.org/articles/on-the-fence/

Listen to Wildlife Ecologist Dave Press Discusses Tomales Point Elk and mention “there was water in the pond up there . . .” at 2:18.

 

It’s time to connect the dots and ask the obvious question: Did PZP lower the herds’ immune system and genetic diversity to the point of making them vulnerable to a die-off?

With suspect data regarding the long-term use of PZP on wild herds, more questions and answers are needed to prevent a similar die-off in America’s wild horses & burros.

With regards to wild horses, keep in mind what Marybeth Devlin wrote about PZP:

“PZP is a registered pesticide whose mechanism-of-action is to cause auto-immune disease. PZP tricks the immune system into producing antibodies that target and attack the ovaries. PZP’s antibodies cause the mare to suffer ovarian dystrophy, oophoritis (inflammation of the ovaries), ovarian cysts, destruction of oocytes in growing follicles, and depletion of resting follicles. Not surprisingly, estrogen levels drop markedly as the ovaries are slowly destroyed. But PZP’s adverse effects are not limited to the individual animal. As a recent study — which included the Little Book Cliffs, Colorado herd and the McCullough Peaks, Wyoming herd — found, PZP extends the birthing season to nearly year-round. Out-of-season births put the life of the foals and the mares at risk. Further, the same study disclosed that the pesticide causes a delay lasting 411.3 days (1.13 years) per each year-of-treatment before mares recover their fertility after suspension of PZP. However, some mares never recover — they are left permanently sterile, and quickly too. Indeed, yet another study found that sterility could occur in some mares from just three years of PZP injections or from just one treatment if the pesticide were given to a filly before she reached puberty. Because PZP messes with the immune system, it ironically works “best” — sterilizes faster — if the mare has a strong immune system. But, conversely, PZP may not work at all in mares whose immune function is weak or depressed. So, the pesticide discriminates against the very horses that Nature has best equipped for survival against disease while favoring and selecting for the immuno-compromised. Worse yet, tests performed via radioimmunoassay indicated that PZP antibodies are transferred from mother to young via the placenta and milk. The transferred antibodies cross-react with and bind to the zonae pellucidae of female offspring, as demonstrated by immunofluorescent techniques.”  [From: http://protectmustangs.org/?p=8529]

 

Pm PZP Darts

Links of interest™:

Immunocontraception (Wikipedia): https://en.wikipedia.org/wiki/Immunocontraception

“Whenever an immune response is provoked, there is some risk of autoimmunity. Therefore immunocontraception trials typically check for signs of autoimmune disease.[17] One concern with zona pellucida vaccination, in particular, is that in certain cases it appears to be correlated with ovarian pathogenesis.[2] However, ovarian disease has not been observed in every trial of zona pellucida vaccination, and when observed, has not always been irreversible.[18]”

 

Autoimmune disease (Wikipedia): https://en.wikipedia.org/wiki/Autoimmune_disease 

“Autoimmune diseases arise from an abnormal immune response of the body against substances and tissues normally present in the body (autoimmunity). . .”

 

ZonaStat-H is the EPA restricted-use pesticide–PZP–for wild horses and burros the registrant calls “pests”: http://www3.epa.gov/pesticides/chem_search/reg_actions/pending/fs_PC-176603_01-Jan-12.pdf

 

Tule elk: http://www.nps.gov/pore/learn/nature/tule_elk.htm

 

Tule elks at Pt. Reyes National Seashore (National Park Service): http://www.nps.gov/pore/getinvolved/supportyourpark/upload/volunteer_docent_info_tule_elk_elkmanagement_v5.0_1.pdf

 

Challenges face tule elk management in Point Reyes National Seashore  http://www.mercurynews.com/pets-animals/ci_28311296/challenges-face-tule-elk-management-point-reyes-national

“Earlier this year park service officials revealed that more than 250 tule elk died inside the fenced area over a two-year period, in part because pools that the herds rely on for water had gone dry. Meanwhile, ranchers are complaining about the free-range elk getting on their land and eating grass and drinking water intended for their dairy cattle and other agricultural operations.”

 

Paratuberculosis or Johne’s disease (Wikipedia): https://en.wikipedia.org/wiki/Paratuberculosis

 

Testing for Mycobacterium avium subsp. paratuberculosis infection in asymptomatic free-ranging tule elk from an infected herd.  http://www.ncbi.nlm.nih.gov/pubmed/12910759

“Forty-five adult tule elk (Cervus elaphus nannodes) in good physical condition were translocated from a population located at Point Reyes National Seashore, Marin County (California, USA), to a holding pen 6 mo prior to release in an unfenced region of the park. Because infection with Mycobacterium avium subsp. paratuberculosis (Mptb) had been reported in the source population, the translocated elk underwent extensive ante-mortem testing using three Johne’s disease assays: enzyme linked immunosorbent assay (ELISA); agar gel immunodiffusion assay (AGID), and fecal culture. Isolation of Mptb was made from fecal samples in six of 45 elk (13%). All AGID results were negative while ELISA results for 18 elk (40%) were considered elevated. Elevated ELISA results or Mptb isolation from fecal samples were obtained for 22 of 45 elk (49%); these elk were euthanized and necropsied. Mycobacterium avium subsp. paratuberculosis was isolated from tissue in 10 of 22 euthanized elk (45%); of these 10 cases of confirmed infection, eight had elevated ELISA results (80%) and four were fecal culture positive (40%). One of 10 cases had histopathologic lesions consistent with Mptb infection. Mycobacterium avium subsp. paratuberculosis was also isolated from tissue from one of eight fetuses sampled. The number of tule elk found to be infected was unexpected, both because of the continued overall health of the source herd and the normal clinical status of all study animals.”

 

Mycobacterium avium subspecies paratuberculosis and Mycobacterium avium subsp. avium infections in a tule elk (Cervus elaphus nannodes) herd. 2006. http://www.ncbi.nlm.nih.gov/pubmed/17255437 

Abstract
“Between 2 August and 22 September 2000, 37 hunter-killed tule elk (Cervus elaphus nannodes) were evaluated at the Grizzly Island Wildlife Area, California, USA, for evidence of paratuberculosis. Elk were examined post-mortem, and tissue and fecal samples were submitted for radiometric mycobacterial culture. Acid-fast isolates were identified by a multiplex polymerase chain reaction (PCR) that discriminates among members of the Mycobacterium avium complex (MAC). Histopathologic evaluations were completed, and animals were tested for antibodies using a Johne’s enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion. In addition, 104 fecal samples from tule elk remaining in the herd were collected from the ground and submitted for radiometric mycobacterial culture. No gross lesions were detected in any of the hunter-killed animals. Mycobacterium avium subsp. paratuberculosis (MAP) was cultured once from ileocecal tissue of one adult elk and was determined to be a strain (A18) found commonly in infected cattle. One or more isolates of Mycobacterium avium subsp. avium (MAA) were isolated from tissues of five additional adult elk. Gastrointestinal tract and lymph node tissues from 17 of the 37 elk (46%) examined had histopathologic lesions commonly seen with mycobacterial infection; however, acid-fast bacteria were not observed. All MAC infections were detected from adult elk (P = 0.023). In adult elk, a statistically significant association was found between MAA infection and ELISA sample-to-positive ratio (S/P) > or = 0.25 (P=0.021); four of five MAA culture-positive elk tested positive by ELISA. Sensitivity and specificity of ELISA S/P > or = 0.25 for detection of MAA in adult elk were 50% and 93%, respectively. No significant associations were found between MAC infection and sex or histopathologic lesions. Bacteriologic culture confirmed infection with MAP and MAA in this asymptomatic tule elk herd. The Johne’s ELISA was useful in signaling mycobacterial infection on a population basis but could not discriminate between MAA and MAP antibodies. The multiplex PCR was useful in discriminating among the closely related species belonging to MAC.
Between 2 August and 22 September 2000, 37 hunter-killed tule elk (Cervus elaphus nannodes) were evaluated at the Grizzly Island Wildlife Area, California, USA, for evidence of paratuberculosis. Elk were examined post-mortem, and tissue and fecal samples were submitted for radiometric mycobacterial culture. Acid-fast isolates were identified by a multiplex polymerase chain reaction (PCR) that discriminates among members of the Mycobacterium avium complex (MAC). Histopathologic evaluations were completed, and animals were tested for antibodies using a Johne’s enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion. In addition, 104 fecal samples from tule elk remaining in the herd were collected from the ground and submitted for radiometric mycobacterial culture. No gross lesions were detected in any of the hunter-killed animals. Mycobacterium avium subsp. paratuberculosis (MAP) was cultured once from ileocecal tissue of one adult elk and was determined to be a strain (A18) found commonly in infected cattle. One or more isolates of Mycobacterium avium subsp. avium (MAA) were isolated from tissues of five additional adult elk. Gastrointestinal tract and lymph node tissues from 17 of the 37 elk (46%) examined had histopathologic lesions commonly seen with mycobacterial infection; however, acid-fast bacteria were not observed. All MAC infections were detected from adult elk (P = 0.023). In adult elk, a statistically significant association was found between MAA infection and ELISA sample-to-positive ratio (S/P) > or = 0.25 (P=0.021); four of five MAA culture-positive elk tested positive by ELISA. Sensitivity and specificity of ELISA S/P > or = 0.25 for detection of MAA in adult elk were 50% and 93%, respectively. No significant associations were found between MAC infection and sex or histopathologic lesions. Bacteriologic culture confirmed infection with MAP and MAA in this asymptomatic tule elk herd. The Johne’s ELISA was useful in signaling mycobacterial infection on a population basis but could not discriminate between MAA and MAP antibodies. The multiplex PCR was useful in discriminating among the closely related species belonging to MAC.”

 

Epizootic of paratuberculosis in farmed elk http://www.johnes.org/handouts/files/Elk_outbreak.pdf

 

TESTING FOR MYCOBACTERIUM AVIUM SUBSP. PARATUBERCULOSIS INFECTION IN ASYMPTOMATIC FREE-RANGING TULE ELK FROM AN INFECTED HERD (Journal of Wildlife Diseases, : http://www.bioone.org/doi/pdf/10.7589/0090-3558-39.2.323

 

Immuno-Contraception Research for Managing Tule Elk Population – Phase I Scheduled to Begin on August 6, 1997 http://www.nps.gov/pore/learn/news/newsreleases_19970805_elkimmunocontraception97.htm

“. . . Funding for tule elk projects has come from a variety of sources. To date, monetary support and in-kind services for the tule elk project has been received from the Rocky Mountain Elk Foundation, Point Reyes National Seashore Association, Committee for the Preservation of Tule Elk, California Department of Fish and Game, The Humane Society of the United States (HSUS), University of California at Davis, the National Park Service Natural Resource Preservation Program and In Defense of Animals.” [Evidently Suzanne Roy, currently the Director of the American Wild Horse Preservation Campaign–who pushes PZP based management–was working for IDA at the time.]

 

Immuno-Contraception Research for Managing Tule Elk Population – Phase II Scheduled to Begin on June 15, 1998  http://www.nps.gov/pore/learn/news/newsreleases_19980615_elkimmunocontraception98.htm

“. . . During the second phase of the contraceptive research project, the first vaccine will be administered by direct syringe injection. To administer the injection, 30 elk will be captured from a helicopter and hobbled by ground crews. Scientists will gather data on the individual elk and place a radio collar on each of the elk. The collar will allow scientists to follow the individual elk to determine the effectiveness of the contraceptive. After several weeks, a booster shot will be remotely administered, from ranges of 30 to 150 feet, by means of self-injecting darts. The darts are brightly colored and easily retrieved. A single annual booster inoculation will be administered to continue contraceptive effects for successive breeding seasons.”

 

Use of porcine zona pellucida (PZP) vaccine as a contraceptive agent in free-ranging tule elk (Cervus elaphus nannodes). published 2002: http://www.ncbi.nlm.nih.gov/pubmed/12220156 

Abstract (note only a 5 year study. Why aren’t they studying the truly long-term effects?)
The potential for the application of porcine zona pellucida (PZP) immunocontraception in wildlife population management has been tested over a 15 year period and promises to provide a useful wildlife management tool. These studies have provided evidence indicating that the use of PZP immunocontraception in wildlife: (i) is effective at both the physiological and population level (Liu et al., 1989; Kirkpatrick et al., 1996; Turner et al., this supplement); (ii) is deliverable by remote means (Kirkpatrick et al., 1990; Shideler, 2000); (iii) is safe in pregnant animals (Kirkpatrick and Turner, this supplement); (iv) is reversible (Kirkpatrick et al., 1991; Kirkpatrick and Turner, this supplement); (v) results in no long-term debilitating health problems (Kirkpatrick et al., 1995; Turner and Kirkpatrick, this supplement); (vi) has no implications for passage through the food chain (Harlow and Lane, 1988); and (vii) is reasonably inexpensive (J. F. Kirkpatrick, personal communication). This report presents the results of a 5 year study in tule elk (Cervus elaphus nannodes), 3 years of which were on the application of PZP immunocontraception to an expanding elk population living in a wilderness area of Point Reyes National Seashore in Marin County, CA…”

 

Copyright Protect Mustangs.org 2016





Science proves PZP is sterilizing wild horses

The truth

The Effects of Porcine Zona Pellucida Immunocontraception on Health and Behavior of Feral Horses (Equus caballus)

Authors: Knight, Colleen M.
Advisors: Rubenstein, Daniel I.
Department: Ecology and Evolutionary Biology

The horse population on Shackleford Banks, a barrier island off the coast of North Carolina, has been controlled using a program of porcine zona pellucida immunocontraception since 2000. Prior studies found no negative physiological effects of the immunization, but suggested some adverse effects on behavior such as increased harem switching and extended reproductive season. Although no mares were immunized in the year of study (2013), we examined the effects of past contraception and foaling on health and behavior of the mares in an attempt to better understand its impacts on both the individual and the population. Current lactation was found to be the best predictor of health and behavior: lactating mares were in worse physical condition, spent more time grazing, and switched harems fewer times. Mares that had never foaled also were in better physical condition than mares that had foaled in the past, but did not differ in behavioral measures. There were indications that the PZP treatment has had effects other than preventing pregnancy: an increased number of years since immunization was correlated with better body condition and fewer harem switches, independent of lactation. Contraception treatment intensity or timing did not have any significant adverse effects on health and behavior on its own. However, three or more consecutive years of treatment or administration of the first dose before sexual maturity may have triggered infertility in some mares. Inducing sterility, while relieving the mares from the energetic costs of lactation and reducing the stress from harem switching, may have unintended consequences on population dynamics by increasing longevity and eliminating the mares’ ability to contribute genetically.

Read more here: http://dataspace.princeton.edu/jspui/handle/88435/dsp01vt150j42p

Sign and share the urgent petition: Grant a 10-year moratorium on wild horse roundups for recovery and studies

PZP is an EPA approved restricted use pesticide and Protect Mustangs is against using it on wild mares especially when there is an underpopulation problem on public land despite government spin. The truth is most wild herds are being threatened with low numbers and a lack of genetic variability.

Immunocontraceptives: Tomorrow’s birth control?

Protect Mustangs is against using PZP and other immunocontraceptives on wild horses and burros at this time because it has not been proven that the herds are overpopulating nor damaging the thriving natural ecological balance and it appears to be risky.

The Bureau of Land Management’s (BLM) Appropriate Management Level (AML) is skewed ridiculously low to appease the public land mining, ranching and energy interests. Livestock is permitted on wild horse rangelands with livestock outnumbering wild horses and burros at more than 50 to 1.

We are very concerned about the low wild horse and burro population levels–estimated at less than 18,000 for the entire West–due to 3 years of roundup rampage.

Roundups will continue in order to administer fertility control unless they are permanently sterilizing the wild horses during roundups now.

Darting is not only a biohazard but is also impractical on rough terrain unless the BLM or their agents are chasing wild horses in helicopters to shoot them with the drug. Chasing herds is cruel.

The 1971 Act made it illegal to chase wild horses and burros with aircraft. Sadly The Act has been whittled away by enemies of the American wild horse and burro. Protect Mustangs is against helicopter roundups and terrorizing wild herds by chasing them over rough terrain where foals have their feet run off and die.

Predators, such as mountain lions, are reducing the population the way nature intended. We support allowing predators on the range.

Immunocontraceptives appear to have many drawbacks that you will read about in the article below. Most studies are paid to prove the drugs are OK so it’s important to notice the negative aspects for a more accurate perspective.

Fertility control is a billion dollar business for the human market. One must question the ethics of using America’s icons as lab rats.

 
Cross-posted  from Pennmidwifery

By Bonnie Urquhart, R.N.

Native Wild Horses in Utah (Photo © Cynthia Smalley, all rights reserved)

Feral mares grazing on Assateague, a barrier island off the Maryland coast, benefit from a contraceptive strategy that would leave many women envious. Their fertility is curbed by a method that employs neither hormones nor devices, but instead convinces the immune system to target reproductive components and render them inactive. Derived from the ova of pigs, the porcine zona pellucida (PZP) vaccine has been administered annually via dart gun to regulate the fertility of these fast-breeding animals since 1988.

An immunized mare comes into come into heat and mates as usual, but as soon as she ovulates, her immune system considers her endogenous zona pellucida foreign and spackles it with antibodies, blocking fertilization with an effectiveness rate of 90-100 percent (Kirkpatrick, Turner, Liu, Fayrer-Hosken, & Rutberg, 1997). Immunocontraception does not alter the normal reproductive behavior of these horses, is usually reversible if used for less than seven years, and does not appear to harm unborn foals if the mother is accidentally injected while pregnant. Until this approach was developed, feral horse overpopulation was a chronic headache for wildlife biologists determined to keep the large animals from outstripping their food supply and outcompeting native wildlife.

Vaccination against pregnancy is itself a unique concept. Traditional vaccines are derived from foreign proteins that sensitize the body to fight off microbial invaders. Immunocontraceptives reprogram the body to attack part of itself by attaching it to a foreign, non-tolerated molecule (Sprenger, 1995) (Schrater, 1995). By focusing on different target molecules, researchers can prime the immune system to thwart the production and transport of gametes, disturb the interaction of the gametes that leads to fertilization, or interfere with implantation. Zona pellucida vaccines focus on what may be the ideal target-the translucent glycoprotein extracellular matrix, surrounding all mammalian ova, that sperm must penetrate to achieve fertilization.

Nearly 100 species have been successfully contracepted with PZP vaccines, including rabbits, dogs, deer, elephants, gray seals, and non-human primates, as well as amphibians and fish. “Its application to wildlife…has been spectacular. We are fourteen years down the road with wildlife and it comes close to being the perfect agent,” says Dr. Jay Kirkpatrick, reproductive physiologist and developer of the PZP vaccine used today for wildlife management (personal communication, October 23, 2001).

Zona pellucida vaccines were being for considered for human contraceptive use long before Kirkpatrick’s research group adapted it for wildlife. Around the time it gained favor with wildlife biologists, researchers seeking human application were becoming quite discouraged. Native pig protein was not suitable for human use, and researchers were unable to develop an effective recombinant or synthetic form of human ZP (Kirkpatrick, 2001). Molecular biologists could synthesize the protein backbone of the molecule, but not the carbohydrate components. Without the carbohydrates, the vaccine would trigger immune response, but could not block fertilization.

Another problem is the vaccine’s tendency to become irreversible over time. Immature eggs within the ovaries are also surrounded by zona pellucida. An agent that sensitizes the woman against zona pellucida not only would cause her body to attack its mature ova at ovulation, but could also provoke an immune attack on her immature egg cells and inflammatory destruction of the ovary itself, causing permanent infertility (Feng, Sandlow, Sparks, & Sandra 1999) (Richter, 1996).

Adverse autoimmune reactions resulting in disruption of folliculogenesis and depletion in the primordial follicle pool have been observed in the ovaries of mice (Patterson, Jennings, van Duin, & Aitkin, 2000). Mares, rabbits, and dogs maintained on long-term PZP have sometimes shown abnormal hormonal profiles and altered estrus cycles. A wild mare vaccinated for three years might take between one and six years to regain fertility. After seven years, she may become permanently infertile. Women who desire a reversible method would find this effect unacceptable, but clinicians might someday find zona pellucida vaccines an attractive option for women who have finished childbearing.

Human immunocontraceptive research is not new. At least twelve studies in the 1920s and 1930s evaluated immunocontraception in the human female, but the trials were not successful and “unspecified ethical restrictions” ended the research (Richter, 1996). Better understanding of immune function and molecular biology has revived interest in immunocontraceptive research over the past two decades.

The most suitable candidates for contraceptive vaccine development are molecules on the surface of the gametes or on the fertilized ovum and early embryo and the hormones hCG and GnRH. Anti-gamete vaccines are the most attractive option because they do not disrupt an embryo after fertilization or alter the hormonal balance, but researchers have so far been unable to reliably block fertilization without introducing cross-reactions with other tissues (Schrater, 1995).

Bringing a product from the laboratory to the pharmacy is a long and expensive process, and funding sources are limited (Klitsch, 1995). After selecting a target molecule for study, biologists must isolate, characterize, and synthesize effective molecules from sperm or ova; understand mechanisms by which the immune system blocks fertility; develop an effective, benign adjuvant; create reliable, inexpensive tests to monitor fertility status in immunized individuals; and carefully evaluate the product for immunological and other side-effects (O’Rand & Lea, 1997) To market an effective immunocontraceptive, developers must progress from creating the vaccine in the laboratory to preclinical studies to clinical trials (Feng, Sandlow, Sparks, & Sandra 1999).

Because research and development are costly and regulatory obstacles to new drugs are forbidding, any pharmaceutical company that puts an immunocontraceptive on the market is likely to emphasize its effectiveness, play down adverse findings, and energetically court clinicians with free samples and gadgets. Artfully crafted advertisements will spark public excitement over this innovative contraceptive method, and as a result patients will request the medication without understanding much about its action. The CNM will serve as intermediary between hyperbole and hope, keeping clients grounded in reality as they discuss benefits and possible adverse outcomes.

Vaccines targeting human chorionic gonadotropin (hCG) show a higher likelihood of success than many other immunocontraceptive projects. Produced by the embryo to sustain progesterone production, hCG allows the pregnancy to establish and maintain itself. If antibodies disable the hCG molecule, progesterone drops and uterine endometrium sheds, preventing implantation. Because the result is loss of an early pregnancy, anti-abortionists strongly oppose developing an effective hCG vaccine and block U.S. government grants that would speed research (Klitsch, 1995). By 1995, three prototype hCG vaccines had undergone limited clinical trials in women (Schrater, 1995). The initial three injections lasted about 6 months, and did not affect menstrual cycles.

Unfortunately, the chemical similarity of hCG to luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH) apparently induces cross-reactions elsewhere in the hormonal system. Blocking some hormones and interfering with feedback mechanisms could conceivably wreak endocrine havoc, perhaps irreparably damaging the thyroid and the pituitary glands (Feng, Sandlow, Sparks, & Sandra 1999) (Richter,1996). The vaccinated woman would produce and then attack reproductive hormones, continuously creating immune complexes that could cause tissue damage. Or perhaps this reaction would prove to be benign; in short-term clinical trials of the hCG vaccine, all subjects developed cross-reactive antibodies to LH, and all continued to cycle normally. Female rhesus monkeys immunized repeatedly for seven years with ovine (sheep) LH became infertile but continued to ovulate, had regular menstrual cycles, and maintained normal pituitary function (Schrater, 1995).

Higher on the hypothalamic-pituitary-ovarian axis is gonadotropin- releasing hormone (GnRH), the hormone that spearheads the production of sex steroids in both men and women. The National Institute of Immunology and the Population Control Council have tested a GnRH vaccine on human subjects, including breastfeeding women (Schrater, 1995). The result is effective-but dramatic. The GnRH vaccine essentially effects non-surgical castration, halting testosterone production in men (with accompanying impotence and loss of body hair) and effecting menopause in women (Richter,1996). Hormonal supplements could remedy the deficit, but consumers are unlikely to find this approach acceptable. This technology would be more applicable to veterinary medicine, making possible non-traumatic spaying and castration and in wildlife biology the reduction of, say, deer herds in suburban neighborhoods where hunting is not feasible. Trials of GnRH vaccines on Norway rats resulted in 100 percent sterility in both sexes (Miller, 1997).

Potentially promising are experimental vaccines that target male FSH receptor proteins, inducing men to produce low-quality sperm incapable of fertilization but sparing them the need for exogenous testosterone supplementation. Other biologists have targeted prostaglandinF2, oxytocin, and structural placental antigens (Feng, Sandlow, Sparks, & Sandra 1999). It is the advanced practice nurse who must serve as the intermediary between technology and the client, translating technical information and exploring treatment options while considering the safety of the product.

Vaccines triggering an immune response against sperm could be used by either men or women. Laboratories have experimented with structural and functional antigens on the sperm itself, and with spermatic enzymes. Target specificity is the stumbling block-an immune response that incapacitates sperm also tends to induce the immune system to attack other organs and tissues as well.

With immunocontraceptives, there is often a reciprocal relationship between specificity and effectiveness. If a vaccine is very specific to one small antigen, there is little danger that the immune system will attack similar targets, but contraceptive action is ineffective. An agent that targets several components is much more effective, but the immune response is likely to involve other tissues. The immune system is intimately connected to every part of the body. The potential for an untoward autoimmune response is great, and tissue injury may be difficult to prevent. But perhaps this damage is purely theoretical: anti-sperm antibodies frequently occur in vasectomized men and some women spontaneously become immune to sperm with no identifiable systemic damage (Schrater, 1995) (Diekman & Herr, 1997). Women sometimes develop immune responses against their own zona pellucida as well, and seem to suffer no other ill effects (Schrater, 1995).

Kirkpatrick reports that Assateague mares, freed from the stress of pregnancy and lactation, have enjoyed improved health since the vaccine program started (Barber &Frayer-Hosken, 2000). Studies in horses and dogs show that although ovarian damage occurs, the PZP antibodies in a vaccinated animal do not cross-react with major organ systems such as the brain, heart, and urinary tract (Barber & Frayer-Hosken, 2000). Research with horses and other animals indicates that offspring born to previously contracepted mares, and even mares who were accidentally vaccinated while pregnant, appear normal and go on to produce normal foals themselves. Damage to human fetuses might be more subtle, perhaps manifesting in a chronically overstimulated or sluggish immune system or in hormonal anomalies that might not appear until puberty. We just do not know.

Potential lawsuits make domestic pharmaceutical companies reluctant to engage in immunocontraceptive research, but several companies around the world are optimistic. Canadian biotech firm Immucon has a patent for a male immunocontraceptive vaccine that neutralizes sperm fertilizing capacity by targeting a crucial zona pellucida sperm-binding protein at the level of the epididymus. The company expects to market the vaccine between 2005 and 2007. Immucon believes that reversible male immunocontraceptives will be an $850 million-a-year industry worldwide, and female immunocontraceptives will be worth $990 million a year (Immucon, 2001). Liability reform may encourage the pharmaceutical industry to conduct more contraceptive research (Klitsch, 1995).

Researchers are also exploring injectable agents that could render a man or woman permanently sterile. This could eliminate the pain and expense of tubal ligation or vasectomy while effectively ending childbearing.

Four out of every ten pregnancies in the world are unplanned-80 million a year (AGI,1997). The World Health Organization estimates that between eight million and 30 million unplanned pregnancies are the result of inconsistent or incorrect use of contraceptive methods or from method-related failure, and 120 to 150 million married women want to limit or space their pregnancies but lack the information and services to do so. Worldwide, 55,000 unsafe abortions take place every day, 95 percent of them in developing countries. Every day, more than 200 women die from these procedures (http://www.who.int/archives/whday/en/pages1998/whd98_10.html.). Optimally spaced and planned pregnancies benefit the health of both mothers and children. World population is expected to reach 10 billion by the year 2050, and overpopulation can lead to poverty, famine, disease, depletion of resources, and environmental degradation (Feng, Sandlow, Sparks, & Sandra 1999).

A safe, reliable immunocontraceptive agent could be the family planning strategy of choice for women in developing countries. Proper implementation, however, could strain resources. Clinicians must perform pregnancy tests before immunization and periodically screen recipients to verify that the vaccine is still effective.

If the perfect immunocontraceptive is developed, there would be tremendous potential for misuse and coercion by population-control programs to reduce the birth rate of the poor, non-whites, and people in Third World countries (Richter,1996). (Schrater, 1995). Judith Richter writes in The Ecologist “within this conceptual framework, birth control is regarded as a weapon of war against the ‘teeming multitudes,’ a war in which people are treated as mere numbers or statistics to be controlled, manipulated reduced and dispensed with” (Richter,1996, page 58). The reproductive rights of individuals could become secondary to the perceived need of the population as a whole.

There have been many documented cases of IUD insertion and sterilization procedures carried out without a woman’s knowledge or consent. Immunocontraception would make it much easier to surreptitiously render a woman infertile. Clinics could administer long-acting contraceptive vaccines to uninformed, unaware patients who think the injection is for protection against disease. Some immunocontraceptive agents, such as anti-sperm vaccines, could sensitize a woman for life, and it is likely she would never know that her inability to conceive was artificially induced. (Richter,1996).

Population-control programs usually focus on women because they are the ones who become pregnant. The subordinate status of women in much of the world makes them less likely to resist coercive fertility regulation policies. Conversely, state-imposed vasectomy programs in China and India led to social unrest and the downfall of a government (Schrater, 1995).

Immunocontraceptive clinical trails show great variability in effectiveness although research subjects are healthy, well-nourished individuals in supervised health-care settings. How effective will these vaccines be when used on anemic, malnourished people with little access to care? Immune response varies greatly between individuals and even within an individual, and the duration of protection from pregnancy may be difficult to predict. Individuals with the tendency towards allergies and autoimmune disease could experience an exaggerated reaction that might render them permanently infertile (Richter,1996). Diseases that suppress immunity might reduce the effectiveness of the vaccine.

Researchers talk of developing a finger-stick kit that could be used in the home so that vaccine recipients could monitor their own fertility status and use additional protection if titers are low. It is unclear how feasible these kits would be in Third World counties with few health care supplies.

The ideal immunocontraceptive would be a highly effective, fully reversible vaccine effective for a predictable period. Today’s immunocontraceptives are prototypes in need of improved formulation that will give longer acting, reliable responses with little chance of cross reaction, and offer a high level of protection against pregnancy. Our knowledge of molecular biology grows daily. New vaccine technology may soon isolate target antigens that are much different from the substances synthesized now, creating a safe, effective product that will change the lives of millions. The leadership of nurse midwives will help clients process information and make informed decisions about contraceptive vaccines when they begin to reach the market.

References

Alan Guttmacher Institute. (1997). Issues in Brief: The Role of Contraception in Reducing Abortion. New York: Alan Guttmacher Institute.

Barber, M. Frayer-Hosken, R. (2000). Possible Mechanisms of Mammalian Immunocontraception. Journal of Reproductive Immunology 46 (2): 103-24.

Diekman, Herr, J. (1997). Sperm antigens and their use in the development of an immunocontraceptive. American Journal of Reproductive Immunology 37(1): 111-117.

“Contraception Update” (1998). FHI’s Contraceptive update: Experimental male methods inhibit sperm Quarterly Health Bulletin Network

Feng, H. Sandlow, J. Sparks, A., Sandra, A. (1999). Development of an immunocontraceptive vaccine: current status. Journal of Reproductive Medicine 44 (9): 759-765.

Kirkpatrick, J., Turner, J.W., Liu, I.K., Fayrer-Hosken, R., Rutberg, A.T. (1997). Case studies in wildlife immunocontraception: Wild and feral equids and white-tailed deer. Reproduction, Fertility, and Development. 9 (1): 105-110.

Kirkpatrick, J. (October 23, 2001) Personal communication with author.

Klitsch, M. (1995). Still waiting for the contraceptive revolution. Family Planning Perspectives 27 (6).

Miller, L., Johns, B.E., Elias, D.J., Crane, K.A,. (1997). Comparative efficacy of two immunocontraceptive vaccines. Vaccine 15 (17-18): 1858-62.

Moudgal, N.R., Jeyakumar, M., Krishnamurthy, H., Sridhar, S., Martin, F. (1997). Development of a male contraceptive vaccine-a perspective. Human Reproduction Update 3 (4): 335-46.

O’Rand, M., Lea, I. (1997). Designing an effective immunocontraceptive. Journal of Reproductive Immunology 36: 51-59.

Patterson, M. Jennings, Z.A., van Duin, M., Aitkin, R.J. (2000). Immunocontraception with zona pellucida proteins. Cells Tissues Organs 166 (2): 228-32.

Richter, J. (1996). “Vaccination” against pregnancy: The politics of contraceptive research. The Ecologist 26 (2): 53-61.

Schrater, A. (1995). Immunization to regulate fertility: biological and cultural frameworks. Social Science and Medicine 41 (5): 14.

Sprenger, U. (1995). Challenging the immune system, the development of anti-fertility vaccines. Biotechnology and Development Monitor 25: 2-5.

World Health Organization. (1998). World health day/Safe motherhood, 7 April 1998: Address unsafe abortion [Online] http://www.who.int/archives/whday/en/pages1998/whd98_10.html.

2001 Bonnie S. Urquhart

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