A promising approach in the treatment of drug addiction is immunotherapy—using vaccines to provoke an immune response to a drug and thereby prevent it from entering the brain, where it would ordinarily produce its pleasurable and reinforcing effects. But a remaining challenge for this therapeutic strategy is mustering a sufficiently robust immune response to counteract a drug’s effects. In this study, researchers tested a new cocaine vaccine that consisted of non-infective particles of adenoviruses (one of over 200 viruses that can cause the common cold) studded with cocaine-derived molecules capable of stimulating anti-cocaine antibodies. (Small foreign molecules, like cocaine, are too small to trigger an immune response unless they are presented on the surface of a suitable large scaffold molecule.) The vaccine (labeled dAd5GNE) produced high levels of anti-cocaine antibodies, and rats that had been immunized had a reduced locomotor response to the administration of cocaine. The vaccinated rats also showed less motivation to self-administer the drug than did rats in a control group and did not revert to drug seeking behaviors in an experimental model of “relapse.” These effects lasted the duration of the study (4 months), and, if replicate in humans, would suggest that a dAd5GNE-based vaccine could be an effective complement in the treatment of cocaine abuse and addiction.
Neuropsychopharmacology advance online publication, 14 September 2011; doi:10.1038/npp.2011.200 - http://www.ncbi.nlm.nih.gov/pubmed/21918504