Vaccine stops cocaine from reaching brain in monkeys

Researchers are one step closer to testing an anti-cocaine vaccine in people. A novel vaccine developed by a team at Weill Cornell Medical College has shown success at reducing the amount of cocaine that reaches the brain.

Antidrug vaccines--first discussed in the 1970s--are an interesting concept. Vaccines typically are designed to guard against diseases, but antidrug vaccines are designed to protect people from abuse and potentially lethal overdose of substances they willingly put into their own bodies. Scientists have been working on cocaine vaccines since the early 1990s, but so far there have been few clinical trials, and the FDA has yet to approve an anti-cocaine vaccine.

While cocaine use has declined in the U.S. over the last few years, overdosing on the drug causes about 5,000 deaths a year, according to government figures.

The vaccine was created by Cornell researchers and is made up of bits of the common cold virus with a particle that mimics the structure of cocaine. It works by essentially eating up the cocaine in the blood before it can reach the brain. The findings were published online in the journal Neuropsychopharmacology.

When injected in monkeys, the vaccine spurred an immune response to the cold virus and the cocaine imitator attached to it.

"The immune system learns to see cocaine as an intruder," said Ronald Crystal, chairman of the Department of Genetic Medicine at Weill Cornell Medical College and the study's lead investigator. "Once immune cells are educated to regard cocaine as the enemy, it produces antibodies, from that moment on, against cocaine the moment the drug enters the body."

Using a radiological technique, researchers were able to measure the effectiveness of the vaccine and show that it stopped cocaine from reaching the brain, thus preventing a dopamine-induced high.

Cocaine, a tiny molecule drug, produces a "high" when dopamine accumulates at the nerve endings in two areas of the brain: the putamen in the forebrain and the caudate nucleus in the brain's center. Cocaine works by blocking the recycling of dopamine--the "pleasure" neurotransmitter--in these brain sections, which causes dopamine buildup.

The investigators do not yet know how often the vaccine needs be administered in humans to maintain its anti-cocaine effect. One vaccine lasted 13 weeks in mice and 7 weeks in monkeys. Human testing of the anti-cocaine vaccine could begin within a year, researchers say.

- read the press release