A new cocaine vaccine is being tested in clinical trials. It block dopamine-transport receptors and the “high” it causes. “high.”
The vaccine consists of molecules of cocaine covalently bonded to a large carrier protein, a recombinant cholera toxin B subunit. The cholera subunit is harmless without the other part of the normal virulent cholera A subunit.
This carrier was chosen because that a cholera subunit vaccine has been administered to millions of people without any adverse effects,
Since Americans are rarely exposed to or even vaccinated against cholera, their immune defense system will probably launch a strong defense against this foreignthis protein and the attached cocaine molecule.
The carrier choice was dictated by the knowledge that a cholera vaccine made from this subunit has been administered to millions of people without any adverse effects, and by the fact that Americans are rarely exposed to or vaccinated against cholera, so most would likely mount a new and robust immune response to this protein and the attached cocaine molecule.
After intramuscular injection, the vaccine enters the bloodstream and triggers plasma cells to produce antibodies to the cocaine molecule as a component of the immunogenic cholera protein. This creates an army of antibodies that can latch onto free cocaine molecules in the bloodstream and, because they are too bulky to fit through tight junctions in blood vessels, prevent the drug from leaving the circulatory system and entering tissues and organs.
Since tiny cocaine molecules that are now bound to big antibodies can no longer cross the blood-brain barrier into the brain, where they would ordinarily block dopamine-transport receptors and cause the buildup of dopamine that users perceive as a “high.” Cocaine that is kept from reaching its “target” in the brain is prevented from triggering reward sensations. With continued, regular booster vaccinations, necessary because the antibody titer declines steeply about 3 months after reaching peak levels, the bonds of addiction may be loosened, giving addicts a stab at kicking their habit altogether.
Excerpts courtesy of http://bit.ly/iP62jc
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