As a scientist, I know that one of the keys to emerging from the current COVID-19 pandemic is a safe and effective vaccine. Over 100 vaccine candidates are being considered and some will soon advance to large human trials. Thousands of people will receive the vaccines. Researchers will see if their infection rate is any different from unvaccinated people’s and verify the vaccine’s safety.
Because, even in the absence of a vaccine, during a span of several months only a small fraction of any population becomes infected, it will require a large number of people and/or a long time to determine whether a given vaccine provides any protection. Meanwhile, hundreds of millions of people in the United States and billions of people worldwide are unprotected, and many will become infected. Some will die, and the longer it takes to determine which are the good vaccines, the more people will die.
There is an alternative — challenge trials. In such trials, a smaller group receives a vaccine and is then deliberately exposed to the virus with a standardized dose. The advantage of such trials is that one does not wait for “natural” infection to happen by chance. Nor does one have the variability of natural infection, from a brief encounter with an asymptomatic individual to a lengthy encounter with a “super spreader.” The disadvantage is that some of the volunteers for such a study are likely to die.
Is this proper? Is it ethical?
I volunteer myself
The ethical status of challenge trials is problematic because COVID-19 can be fatal, with no known effective therapy. Some traditional rules for human subject studies preclude challenge trials in this case.
Various specific ethical arguments against challenge trials arise. Some contend that infecting subjects violates the Hippocratic oath, often expressed as, “First, do no harm," and conjures up memories of clearly unethical studies like Tuskegee. Others argue that if a candidate coronavirus vaccine turns out to be ineffective, some brave volunteers, who would have lived, might die for nothing. I reject these ideas and argue that we should embrace challenge studies.