One-Dose Contraceptives…For Cats, At Least

Veterinarian Dr. Judy Levy from the University of Florida has put immunology to work in testing out what could be a breakthrough in controlling the feral cat population.  Her group tested out the contraceptive vaccine GonaCon on laboratory cats (which were subsequently all adopted).  GonaCon works by stimulating production of antibodies to GnRH, a hormone that in turn signals the production of sex hormones, including those involved in sexual behavior and ovulation.  By binding to GnRH, the antibodies induced by the vaccine interfere with GnRH’s activity, preventing the release of these sex hormones. This inhibits sexual activity and the animals will remain nonreproductive as long as sufficient GnRH antibody levels are present.

The vaccinated cats all responded to the vaccine with varying levels of success, but overall the trial was a success.  Dr. Levy found that the vaccine (which was originally formulated for use on deer, but also works on other mammals) was safe and long-lasting after just one dose.

Vaccinated cats had a longer time to conception (median 39.7 mo) compared to sham-treated cats (4.4 mo; P < 0.001). A total of 93% of vaccinated cats remained infertile for the first year following vaccination, whereas 73, 53, and 40% were infertile for 2, 3, and 4 y, respectively. At study termination (5 y after a single GnRH vaccine was administered), four cats (27%) remained infertile.  (Journal of Theriogenology - login required for full article)

Not a bad turn out.  This seems like a promising method of contraception for feral cats.  Granted, it doesn’t have extremely long-lasting effects in all cats, but still, if it makes a female miss even a few breeding cycles, that can be a few litters of feral cats prevented.  GonaCon is also evidently fairly cheap, so it is a cost-effective method of sterilization compared to spaying.

- via

The Cocaine “Vaccine”

What if you could actually make antibodies against an illegal substance you were addicted to, like cocaine?  What if you made enough of them to prevent the drug from getting into your brain and getting you high?  What if such a regimen could take away the incentive to use the drug?  Such a “cocaine vaccine” is in clinical trials and is showing some promise in helping addicts reduce their cocaine use.  The latest study is published here, and a very good, accessible summary of the issue by Walter Armstrong is here on

Armstrong points out quite rightly that the “vaccine” (and I keep using quotes because it’s not really a vaccine…it doesn’t prevent a disease) does not magically allow an addict to go cold turkey.  It doesn’t help with cravings or other withdrawal symptoms.  However, it does help addicts committed to recovery reduce usage and prevent backsliding, because the drug won’t get them as high anymore.  The percentages of people this actually works in is significant but less than miraculous (only about 20%.)  Therefore:

“I believe that this approach will work for motivated patients in that it will buy them a period of time where cocaine’s effects are blunted, allowing them to focus on treatment. There are clinical data supporting this idea,” says Haney, whose own study of measuring TA-CD antibodies in crack smokers was published in Biological Psychiatry in 2009.”

Armstrong really gets at the crux of the issue here:

TA-DC will join the many other, only partially effective behavioral treatments for cocaine addiction. Its trailblazing as the first vaccine against an illegal drug may, in the long run, matter even more.

Thus, it’s no magic bullet, but the idea is pretty cool and worth pursuing.

Another interesting thing are the comments on the Armstrong article, but the pschology at work there is another whole post, I imagine.