On the phone last night with my mom, I started complaining about how late in the season my office would be providing its employees with flu shots. She asked me if I was planning to get one, and like any good graduate of public health school, I answered yes and somewhat pretentiously added, “I very much believe in vaccines.” It’s one of those beliefs I take for granted; I have always opted for preventing problems over fixing them, both in health and in life in general, and a vaccine policy course I took earlier this year only cemented that approach.

But while reading the Washington Post Express on the metro this morning, I came across an article that got me thinking about it again (see pg.3). The piece described a recent study on a drug designed to prevent cocaine users from experiencing the high associated with cocaine, and thereby reduce their use. In the study, published by Dr. Bridget Martell and colleagues in the October issue of the Archives of General Psychiatry, subjects received a vaccine that stimulated the production of anticocaine antibodies. Those who had more antibodies were found to cut their cocaine use by as much as half. The Express article also mentioned that the National Institute on Drug Abuse (NIDA) recently announced plans to study a nicotine vaccine aimed at helping people quit smoking.

It’s a promising idea that’s coming up more and more frequently now: vaccines as treatment for drug addiction. Besides stimulating antibody production, how these vaccines differ from other medications that reduce the appeal of drugs and tobacco is, honestly, a little beyond my scientific expertise, but there’s another important question that gets hinted at in all of these articles. If vaccines can be used to treat addiction, to prevent relapse, can they be used to prevent addiction in the first place? And should they?

Let me be clear – scientifically, we’re not there yet. Wayne D. Hall writes in PLoS Medicine of a number of practical hurdles that must first be addressed before mass prevention of addiction by vaccines is even possible. Existing drugs are not fully effective. Nor does that partial effectiveness last very long, creating the need for frequent booster shots. Like any other vaccine, side effects must be evaluated and addressed. And policy questions about cost and eligibility pose another barrier to implementation.

Setting those issues aside, though, there seems to be something fundamentally different about using vaccines to prevent infectious diseases and using them to prevent addiction. It’s something more than the stigma associated with addiction, but it is related. After reflecting on it this morning, I realized what that difference was: infection, mostly, is a chance event. Addiction, mostly, is not. Sure, we can choose to not hug our friend with the flu or sit next to that person with the runny nose, but we can’t decide to avoid an airborne virus the same way we can decide to say no to that first cigarette.

Or to other potentially risky behaviors, for that matter. We’re starting to skirt the line between chance and controllable events. Since the release of Human Papillomavirus (HPV) vaccines a few years ago, states have been debating school entry mandates, insurance coverage requirements, and other policies relating to the vaccine. In those debates, I saw a lot of the same logic as in the addiction vaccine question – HPV is a sexually transmitted disease, and so infection is at least somewhat in the control of the person choosing to have sex, just as addiction is at least somewhat in the control of the person choosing to use a drug. For that reason, I expect to see a lot of the same arguments used, as the scientific questions about the prevention of addiction by vaccines start getting answered and it becomes more of a policy question.

Quite honestly, I’m not sure how I feel about the use of vaccines to prevent addiction. Would I choose to vaccinate myself? Probably not. Would I vaccinate my future children? That’s more debatable. On what basis would I decide? At that point, we start getting more questions than answers. What I do know is that if and when the time comes to decide, it’s going to be a challenge.