Ethics of vaccine testing

The morning paper brought news of an AIDS vaccine that was found to be ineffective; which led me to the following question:

Are there ethical guidelines and standards about how to manage expectations in the subject of a clinical trial? Specifically, if a subject knows that he’s participating in a trial of an AIDS vaccine, how do you counter the (hypothetical) tendency to be less careful about safe sex?

This wouldn’t be a problem for, say, a smallpox vaccine–I doubt many participants would say “woohoo! I’m gonna expose myself to smallpox!” But if lifestyle is a contributing factor to the disease, I would think this might be an issue.

Granted that the participants are undoubtedly briefed that they might have gotten a placebo, or that the vaccine was ineffective (which it was, in this case). But if one person catches AIDS because he didn’t use a condom because he’d gotten the shot–that would be an awful price to pay.

There aren’t specific “stringent guidelines” but there is a stringent requirement that all such research be approved by an institutional review board (often multiple insitutional review boards) that are charged with protecting human subjects from research risks and that agree to be guided by any one of several generally accepted sets of ethical guidelines.

The problem you mentioned is a serious but unavoidable one. All that one can do is inform the subjects of their risk and strongly encourage them to avoid exposure. In can happen that the advice to avoid exposure is followed by so many of the subjects that there are so few infections in the placebo group that no conclusion can be drawn from the experiment. But that’s a risk that the researchers have to take.

I remember an AIDS-vaccine study done earlier in which the researches sought out gay men leading extremely promiscuous lives who knew they were already at risk for AIDS and weren’t going to change their behavior no matter what. (Not exactly bug-chasers, but almost.)

By having these men as test subjects, you’re assured of getting good exposure to AIDS without worrying about encouraging such behavior. Finding enough subjects took a while though.

I listened to David Baltimore on PBS today on this very topic. In addition to informed consent for the HIV vaccine testing, all subjects also were educated about safe sex and reducing risk as much as possible. The investigational team really did try to reduce their risky behavior, but they knew that whatever they told them, a certain number would go out and practice unsafe sex. Just as in real life. So they probably educated a few enough to change their behavior, and still got the exposures and new cases they needed to test the vaccine. It’s really win-win, even tho it seems a bit icky.

I’ve been wondering about a similar question. Not so much vaccines, but trials for cancer drugs. How do researchers ethically decide who gets the stuff and who gets the placebo? Are placebos even given in such a case? I would feel cheated if I had cancer and I found out the drugs worked on someone else, but I had a placebo and it was too late for me. So how do trials work in a life and death situation like that?

The American Cancer Society’s web page says that, instead of a placebo, you would get whatever drugs you’d normally get. link