For one thing, the broken fragments just slip away, leaving the antibody free to work again. The vaccines are at last looking as though they might be a more promising treatment than the small chemicals. Antibodies don't mess with brain chemistry the way blocking drugs do, so there should be fewer side effects. If they only have to make that decision every few weeks, it would be a great relief. He thinks antibodies would be a big help to recovering addicts who have trouble sticking with their therapy.
Researchers are confident they can push the vaccine technology even further.
And they have another reason to be optimistic. One experienced nothing from the drug, the other felt his heart race, but didn't achieve a high. Tom Kosten, a psychiatrist at Yale University who conducted the trial, says that if this anecdote foretells that effective immunotherapy is possible, then he, for one, will gladly confront the moral and medical morass that will follow.