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What Is the Porcine Zona Pellucida (PZP) Vaccine and How Does It Work?
A non-cellular membrane known as the zona pellucida (ZP) surrounds all mammalian eggs. The ZP consists of several glycoproteins (proteins with carbohydrates attached), one of which, ZP3, is the sperm receptor (the molecule which permits attachment of the sperm to the egg during the process of fertilization).
The PZP (Porcine Zona Pellucida) vaccine is derived from the ZP protein from porcine ova. PZP is produced by a complex process whereby the ZP is removed from the ovum, the glycoproteins are extracted, isolated, and converted into a vaccine. The PZP is emulsified with an adjuvant to which stimulates the animals’ immune system.
When this vaccine is injected into the muscle of the target female animal, it stimulates her immune system to produce antibodies against the vaccine. These antibodies also attach to the zona pellucida (sperm receptor) of the female’s own eggs distorting their shape, thereby blocking fertilization. In this adaptive system the immunological memory allows for the booster inoculations to have a more vigorous reaction thereby activating an immune response that blocks fertilization again
The PZP vaccine is usually given in a series of 2 vaccinations, 2-6 weeks apart, and then a booster every 8-12 months, depending on the species.
To achieve effective PZP contraception, the initial treatment should be consistent with the seasonal pattern of reproduction for the individual species.
For species with a well-defined and short (2-3 months or less) breeding season , a minimum of two inoculations should be given during the first year of treatment. The first inoculation (primer) can be given any time of the year but the second inoculation must be given 1-2 months prior to breeding activity but no sooner than 2 weeks following the primer dose.
Until data are obtained that suggest otherwise, single annual booster inoculations may be given during subsequent years in some species. In year-round breeders, evidence indicates that booster inoculations should be given every seven to eight months (see Frank et al. 2005).
The standard dose of PZP antigen for animals is 100 µg of protein in phosphate buffered saline or sterile water. This dose may be adjusted downward for some species and will be determined prior to administration.
PZP (or ZonaStat-H) is federally approved (EPA reg. no. 86833-1), thus individuals are required to undergo training through the Science & Conservation Center and obtain a pesticide applicators license through their state agency which represents the EPA (in Montana it is the Montana Department of Agriculture), prior to receiving or applying the PZP vaccine to wild equids.
Equine contraceptive certification is offered at various times throughout the year. Training takes place over 3 days at the Science & Conservation Center during which attendees receive both educational and hands-on training.
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Location: Africa
Population: 415,000
African elephants possess remarkable communication abilities. They employ various vocalizations like trumpets, roars, and rumbles to convey different messages within their herd. Alongside vocal cues, they also utilize body language, such as ear movements and trunk gestures, to express themselves. Among these, the low-frequency rumbles stand out, capable of traveling over long distances, playing a pivotal role in facilitating long-distance communication among these intelligent and sociable creatures.
The Science and Conservation Center is an independent non-profit organization dedicated to the development of humane wildlife contraceptives and methods of application. Our research supports the transition to safe, humane, and publicly acceptable wildlife management paradigms that are beginning to replace human-imposed lethal methods.
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