Nicotine Vaccine Being Developed to Help Smokers Quit

by Dr Sam Girgis on June 27, 2012

Tobacco smoking has well known negative consequences on mental and physical health.  These include increased risk of heart disease, stroke, and cancer.  Ultimately, tobacco smoking leads to the development of chronic bronchitis and emphysema. According to a 2008 survey conducted by the National Center for Health Statistics, in the United States an estimated 24.8 million men (23.1 percent) and 21.1 million women (18.3 percent) are active smokers of tobacco.  The following statistics were also cited:

  • Among whites, 23.5 percent of men and 20.6 percent of women smoke (2008).
  • Among blacks, 25.6 percent of men and 17.8 percent of women smoke.
  • Among Hispanics, 20.7 percent of men and 10.7 percent of women smoke.
  • 9.9 percent of Asian adults smoke.
  • 24.3 percent of American Indian/Alaska Native adults smoke.

Tobacco use is highly addictive and has been thought to be more addictive than alcohol, cocaine, methamphetamines, and even heroin.  More than half of tobacco smokers who quit will relapse during the first few days due to withdrawal symptoms.  Many tobacco smokers have a strong desire to quit smoking, but have failed a number of times even with the help of nicotine patches, nicotine gum, and medications.

A newer approach to quitting tobacco smoking is the use of a nicotine vaccine, which would block the effects of nicotine on the body.  We have previously discussed the development of a heroin vaccine that has shown promise in the treatment of heroin dependence.  Researchers from Weill Cornell Medical College in New York City lead by Dr. Ronald Crystal, have developed a nicotine vaccine that is highly effective in blocking the physiological effects of nicotine in the body.  The results of their research are published online in the journal Science Translational Medicine.

The researchers have developed a nicotine vaccine that helps the body produce antibodies that bind to nicotine and neutralize its effects on the brain and cardiovascular system.  The authors of the current study used a novel technique to produce their nicotine blocking effects.  They constructed an adenoviral associated vector that expressed an anti-nicotine monoclonal antibody.  The vector was injected into laboratory mice, and was found to produce a very high and stable antibody titer.  When the mice were injected with nicotine, the antibodies produced as a result of the nicotine vaccine bound to nicotine and neutralized its effects.  The nicotine concentration in the brain of the vaccinated mice was only 15% of that found in the brains of unvaccinated mice.  In addition, the vaccinated mice did not show the hallmark effect of nicotine on blood pressure, heart rate, and general locomotor activity.

The authors wrote, “In mice treated in this way with [the nicotine vaccine], parenterally administered nicotine became bound to antibody and was sequestered in the blood, preventing the drug from reaching the central nervous system, even when the animal was challenged with a dose higher than that seen in chronic smokers. Mice expressing the vector-derived antibody failed to respond to nicotine with the usual alterations in cardiovascular function or in ambulatory and vertical locomotor activity. If, in additional experiments, [the nicotine vaccine] can interfere with nicotine self administration in a rodent model of human addiction, this therapeutic approach will be a good candidate for human clinical studies”.

This is a remarkable milestone in the development of a nicotine vaccine.   Future studies will need to show efficacy in primates, before human clinical trials can begin.  In addition, future studies should focus on determining whether this nicotine vaccine can block the continual self administration of nicotine along with blocking its physiological effects.

 

Reference:

Martin J. Hicks et al. “AAV-Directed Persistent Expression of a Gene Encoding Anti-Nicotine Antibody for Smoking CessationScience Translational Medicine, 2012 DOI: 10.1126/scitranslmed.3003611

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