Hormone-Blocking ‘Vaccine’ Could Sterilize Animals With Just One Shot

Good for shrinking populations of pets and pests alike

Photographer: Geoff Stearns

Scientists have long sought ways to stop animal populations from growing too large, but current methods are often expensive or labor-intensive. Now a team of researchers from the California Institute of Technology has discovered a method that could render animals sterile with a single injection, according to a study published today in Current Biology.

In humans and all other mammals, gonadotropin-releasing hormone (GnRH) spurs the development of eggs and sperm. In this study, the researchers tested a shot that contains a small amount of DNA that enables muscle cells to produce special antibodies that attack GnRH. In the study, the researchers gave the shots to mice; two months later, after their bodies had started producing enough antibodies, the mice were completely infertile. And unlike similar methods that use the immune system to create these antibodies, this method could work for 10 years or more in animals without the need for booster shots, since muscle cells are some of the longest-lived in the body.

If this method proves to be similarly effective in other species, it could replace spaying or neutering household pets like cats and dogs. But it could also be helpful to limit the numbers of pest species, such as deer (many of which currently receive hormone-blocking shots every few years) or rodents such as, well, mice.

One day, similar technology may even work to make reliable long-term birth control in humans, according to Science News. But in the more foreseeable future, finding a way to easily reduce the large populations of feral cats or destructive deer might just be enough. As Science notes, “A cheaper, faster method of sterilization is considered a holy grail for animal population control.”

The researchers are now working on new ways to block other hormones that might be more effective in sterilizing other species. If they are successful, that holy grail may soon be within reach.