CHICAGO -- Vaccines, the most potent medical weapon ever devised to vanquish deadly germs, are being called on to do something totally different and culturally revolutionary - to inoculate people against bad habits such as overeating, cigarette smoking and drug use.
Whether this new era of vaccine research can actually subdue many of the poor lifestyle choices that are today's biggest threats to health, causing obesity, cancer, heart disease and other problems, has yet to be proved.
But the evidence is promising enough to persuade the federal government to put millions of dollars toward finding out whether two of the vaccines can end nicotine and cocaine addiction.
The National Institute on Drug Abuse, which has spent $15 million on clinical trials for the vaccines and plans to spend more, predicts that one of the nicotine vaccines might be available for marketing in three years.
"The American Cancer Society has projected that we will have 1 billion people die from smoking in the world in this century," said Frank Vocci, director of medications development for the institute. "If you had a vaccine that helped people quit and stay quit, or prevent them from smoking, that's where you'd get the greatest public health benefit."
Meanwhile, results from a major obesity vaccine trial under way in Switzerland are expected this year, and company officials are hopeful that the vaccine could be ready for use in a few years if all goes well.
To block deleterious behavior, the new vaccines employ the body's natural immune system in an innovative way. Instead of building antibodies to destroy germs as traditional vaccines do, they construct antibodies that lock onto nicotine and cocaine molecules, preventing them from reaching the brain.
"What we're seeing is a renaissance in vaccine technology," said Dr. Gary J. Nabel, director of the National Institute of Allergy and Infectious Diseases' Vaccine Research Center. "It's only natural that when you have a technology that's this powerful, it can be applied to other medical problems."
Normally, nicotine and cocaine molecules are too small to be seen by the immune system.
So to make the vaccines, scientists attach these molecules to big target proteins, such as harmless viruses or bacteria, which the immune system can recognize and attack with specialized antibodies.
