A plea for sanity on human challenge trials

In human challenge trials, willing volunteers are paid to be infected with a vaccine and then subsequently deliberately infected with COVID to test whether the vaccine works. The UK recently allowed human challenge trials, but there is a worldwide prohibition on such trials due to the disproportionate influence of certain bioethicists on government policy. The ethical case for legalising human challenge trials is extremely strong and the arguments against are extremely weak.

The costs of delay

The Moderna vaccine was invented on January 13th 2020. Since then, 1.75 million have died of Covid despite massive social restrictions, and there has been an enormous global recession. The Moderna vaccine was eventually approved in the US in December. Each day that approval is delayed, thousands of people die from COVID.

This is a very large cost of prohibiting human challenge trials, which we need to be cognisant of. The arguments against such trials needs to be extremely strong to merit prohibiting the trials. What are the arguments against?

Arguments against

One possible argument is to argue that we should not expose volunteers to risk of death. This is a bad argument for several reasons. Firstly, we already allow people to do this. People volunteer to accept a risk of death when driving a car. So do kidney donors. Ice road truckers voluntarily accept a risk of death in exchange for money, as do soldiers, firefighters and oil rig workers. The social benefits of allowing these people to do this are miniscule compared to those produced by human challenge trials.

Secondly, in the status quo of delaying approval by six months, we expose far more people to the risk of getting COVID without pay, involuntarily, and with much less active monitoring and treatment. To get an adequately powered trial, you would need to infect a few hundred people with the virus. Since the summer, nearly 2 million more people have contracted COVID in the UK alone – again they did this without compensation and involuntarily. As I write, 50,000 people are contracting COVID every day in the UK. It is a bizarre ethical system that holds that the status quo is superior running to a challenge trial with a few hundred voluntary participants in March.

Another argument appeals to concerns about justice. We would get most information from including at-risk groups. Charles Weijer argues that this would violate justice because it would include certain minority groups such as blacks and South Asians.

This is a bad argument for several reasons. Firstly, the trial need not include such groups but could instead include middle aged or elderly anglo-saxons, Jews or East Asians. Secondly, in the status quo, far more blacks and South Asians will get the virus without pay, involuntarily and with far less monitoring and treatment. This is clearly worse for disadvantaged groups than participation of a few dozen representatives of those groups in a challenge trial.

Thirdly, the volunteers have voluntarily accepted this risk, which, as I have noted above, we usually take to be reason to allow them to do so in other domains.

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