The conceptual battle against smoking has been won; most smokers acknowledge that smoking damages their health. However, awareness is not enough. Very few attempts at quitting are successful despite the vast assortment of available cessation-aids. Undoubtedly, part of the failure of these cessation-aids can be attributed to the strength of nicotine addiction, but it is also possible that the main methods for quitting are ineffective. Quitting cold turkey requires constant willpower, and quitting with the help of a nicotine patch prolongs dependence on the drug. There is another method that may be able to avoid these two pitfalls: blocking nicotine from affecting the body.
The results of a trial with a nicotine vaccine called NicVAX just appeared in Circulation. This vaccine stimulates the immune system to target nicotine before it can produce a high. After getting this vaccine, a long-term smoker, accustomed to relying on dozens of cigarettes to get through the day, cannot derive any pleasure or relief from smoking. This obviously makes it much easier to quit. While the withdrawal symptoms may be intense, there is no relief to be gained from cheating and thus little urge to continue smoking.
The idea of neutralizing nicotine in the body is not entirely new. Last year, the drug Varenicline was approved as a cessation-aid. Varenicline, a partial agonist, binds to nicotine receptors before nicotine can get there, and prevents full activation. This mechanism was certainly a conceptual breakthrough, but it does not address one of the two chief reasons that quit attempts are unsuccessful: they require constant willpower. The FDA recommends taking two doses of Varenicline daily. This allows absentmindedness to ruin an attempt with just a few missed pills, and it also opens the possibility for patients to deliberately stop their medication when the desire to enjoy nicotine becomes too great. In the course of any quit attempt, there may be short periods where the craving becomes overwhelming. The vaccine NicVAX fixes this problem because the shots remain potent for more than a month. If you have your shot for this month, you do not have to rely on willpower to stop you.
The NicVAX trial divided 300 subjects into placebo and vaccine groups. After five months of shots, the subjects’ carbon monoxide levels were tested to see if 8 weeks of abstinence had been attained. The results were encouraging, but did not show impressive aid for the majority of subjects. The level of help that NicVAX conferred correlated with the level of nicotine antibodies. Looking only at the 30% of subjects with the highest levels of antibodies, we can see that 24.6% from this group were able to quit. This is twice as high as the 13% of the placebo group that managed to stay away from cigarets. The difference clearly shows that not everyone’s body can be induced to produce antibodies in the same way, but that antibodies are effective if present.
This newest trial gives credibility to the idea that we should explore alternative mechanisms for helping smokers quit. While NicVAX did not help the majority of subjects, it did support the third of subjects whose immune systems responded actively to the vaccine. With a few different vaccines, and periodic antibody tests, it should be possible to help a larger portion of those who want to quit. The somewhat disapointing results from NicVAX may rise much higher once therapy is given alongside the vaccine. Smoking raises the risk of innumerable health problems, from cancer to cardiovascular disease, so any percentage increase in smoke-free citizens would save many lives.
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