First Cocaine Vaccine Being Tested in Humans
Kantak, a professor of psychology at Boston University, paved the way for Kosten's trial by investigating the effects of TA-CD on rodents. She found that vaccinated rodents stopped self-administering cocaine, even when the doses were six times higher than what they were used to. In other words, the vaccine blunted the effect of cocaine even at very high doses. "It is more of a deterrent because if [a user] happens to take it, they won't get the usual effect. At some point, they are going to be able to find a dose of cocaine that will overcome the antibody, but it would be very cost-prohibitive," she says.
Vocci says that NIDA is funding three different cocaine vaccine trials, including Kosten's, "to the tune of $1 million a year." Kosten's is the only one that is being conducted in humans. One of the other vaccines, being developed at the Scripps Research Institute in La Jolla, Calif., works on the same principle as TA-CD. The third, being developed at the University of Cincinnati, also acts via antibodies, although it works in a slightly different way.
There is also a fourth vaccine in the pipeline, being developed at Columbia University, that works on an altogether different principle called catalytic antibody. "What this would do is increase the conversion of cocaine into an inactive substance," says Vocci. "By [breaking down] cocaine in the bloodstream, the vaccine would stop the drug before it has a chance to enter the brain."
While Kosten's vaccine is the one farthest along in development, Kosten and Vocci both agree that it will be at least several years before it is commercially available. In the meantime, questions about its efficacy in humans are still unanswered.
Vocci explains that we have yet to see whether the vaccine will actually work to stop people from using cocaine, even if it does what it should do. He says that some people still take drugs even when they are not experiencing the high. Even so, Kosten says that he is optimistic that the vaccine can help users stay away from cocaine.