In the early 1990s, researchers at Dalhousie University
(Halifax, Nova Scotia) undertook the challenge of developing a contraceptive
vaccine for potential use on seals. Knowing from the outset that
seals would not be accessible for more than a single inoculation,
the Dalhousie team set their minds to creating a single-dose, long-lasting
vaccine. They developed a unique means of delivering the PZP antigens
to the immune system in liposomes, which are submicroscopic, multi-layered
vesicles. This liposome technology is responsible for the extraordinary
efficacy of SpayVac™. The work that began at Dalhousie is
being continued by ImmunoVaccine Technologies, Inc. (IVT).
For more information about IVT's liposome technology, visit www.immunovaccine.com and open the VacciMax™ link.
Independent trials have shown that a single dose of SpayVac™
can contracept deer for at least 3 years. No treated deer became
pregnant over 3 years in trials on Fallow Deer by TerraMar Environmental
Research Ltd., or on White-tailed Deer by the USDA’s National
Wildlife Research Center conducted at Penn State University.
long-lasting, single-dose efficacy contrasts sharply with the results
of other PZP vaccines, which require frequent boosting. When other
vaccines are used, previously treated animals have to be relocated
before each breeding season and given a booster dose, usually with
a dart. Repeated boosting exposes the animals to increased stress
and greatly increases the cost and technical difficulty of implementing
IC to control deer populations. SpayVac™ removes these impediments.