Deer Contraception

The first question many people ask is, "How do these immunocontraception drugs actually work?" Current research has discovered that PZP (Porcine Zona Pellucida) has the most promise as a fertility control agent. Basically, the PZP vaccine causes chemical layers surrounding the doe's egg(s) to become impervious to sperm so fertilization can not occur. Dr. David Samuel (author of Know Hunting) explains the biological process surrounding the chemosterilant process as "something similar to the allergy shot you get for pollens or other foreign substances that enter your body. With deer, the shot triggers the doe's immune system to build up antibodies against the antigen (i.e. PZP). When sperm tries to enter into the egg, the doe now has an antibody against PZP, and the deer remains sterile."