Current Projects with SpayVac (pZP vaccine)

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A group of 25 female red deer (Cervus elaphus) are currently being treated with SpayVac and fitted with GPS collars for a monitoring period of 2-3 years.  Pregnancy status of the animals will be checked by analyzing fecal samples to identify individuals genetically and then quantify their steroid hormone concentrations. SpayVac has performed very well in the past (87-100% efficacy over 3+ years) with several cervids, including fallow deer (Dama dama) and white-tailed deer (Odocoileus virginianus).  This is a collaborative project, which will also be comparing behavioral differences between pregnant and non-pregnant animals.

In November 2019, a collaborative study was initiated to test contraceptive efficacy in a population of free-ranging macaques (Macaca mulatta).  The breeding season for macaques is in December-March, their gestation is 5½ months long, and births typically occur in May-August.  Fifty female rhesus macaques have been vaccinated, and we are optimistic about SpayVac’s ability to effectively contracept these primates based on positive results from an earlier trial conducted in Hong Kong.  Macaques are considered to be an invasive species in some parts of the world, including Florida and South Carolina.  Populations are often overabundant, which is especially problematic when they live in close proximity to humans in urban and semi-urban areas.  They can cause damage to property and agriculture in addition to spreading zoonotic diseases.  SpayVac’s ability to provide multi-year contraceptive efficacy with a single injection makes it an excellent option for free-ranging primate population control. 

This coming spring, a group of 48 free-ranging horses (Equus caballus) in Europe will be vaccinated with SpayVac and tracked for 5 years to test potential differences in contraceptive efficacy based on 1) 200 versus 400 µg pZP doses, and 2) neck versus rump injections.  Previous studies suggest that injection site may affect vaccine efficacy because of proximity to primary lymph nodes (see 2018 review by Bechert and Fraker in Human–Wildlife Interactions 12(1):117–130) http://bit.ly/2TCag4I

Dose may also play a role in long-term immunocontraceptive efficacy.  This will be a collaborative project with an international animal welfare organization that is also interested in contracepting this population of animals, along with 52 other mares that are less accessible.