SpayVac is an immunocontraceptive vaccine that uses the pZP antigen in a patented liposomal delivery system to create an immune response. The immune system of the inoculated animal will produce antibodies to pZP. These antibodies competitively bind to the pZP surface matrix thus blocking sperm from being able to bind and therefore preventing fertilization.
pZP means porcine zona pellucida.
Zona pellucida is a glycoprotein which is found wrapped around mammalian eggs. One of these glycoproteins, ZP3, is a critical receptor protein for sperm and therefore key to the fertilzation of the egg. The pZP vaccine is derived from porcine (or pig ovaries) and therefore, when referring to the antigen used in the vaccine, it is called pZP.
When the SpayVac vaccine is injected into the female mammal, it stimulates the immune system to produce antibodies against the ZP protein. These antibodies will attach to the ZP layer around the outside of the egg where there are sperm receptors. These antibodies occupy all the receptor sites blocking sperm from fertilizing the egg.
There have been multiple studies demonstrating efficacy in several overabundant wildlife populations such as wild horses, urban deer, seals, wild burros, and elephants. A single dose of SpayVac has demonstrated long-acting contraception. To see the list of publications follow this link to the More About SpayVac page
SpayVac is not yet approved in the USA or Canada for sale. SpayVac will be submitted for registration with the EPA in 2018. It can be purchased for field trials with an Experimental Use Permit. Please contact us for more details if you are interested.