About pZP

Close up image of the zona pellucida, mesh-like protein, on the surface of a pig's egg

What is SpayVac?

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 ZP.  These antibodies competitively bind to the ZP surface matrix thus blocking sperm from being able to bind and therefore preventing fertilization. (pictured right: ZP or zona pelucida matrix covering an mammalian egg)


What does pZP mean and what is it?

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.

More on SpayVac

How SpayVac works.  The mechanism of action: antibodies block sperm and egg binding.

How Does SpayVac Work?

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.

How antigens stimulate the immune system to drive a response to SpayVac pZP vaccine

Has SpayVac been tested?

There have been multiple studies demonstrating efficacy in several overabundant wildlife populations such as wild horses, deer, macaques, 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


Is SpayVac approved?

SpayVac is not yet approved in the USA or Canada for sale.  SpayVac will be submitted for registration with the EPA in 4Q2019 and approval is expected in 4Q2020.  It can be purchased for field trials with an Experimental Use Permit as part if a research project prior to approval.  Please contact us for more details if you are interested.  We are experienced in running trials and can help obtain the necessary permits for testing.