The call has been put out for volunteers aged 18-30 to take part in Government backed human challenge trials (HCT) in the ongoing fight against COVID-19. There is a four stage process to assess whether a drug can be considered for licence. A challenge trial involves giving a number of volunteers a vaccine and then purposely exposing them to the virus in a controlled environment to assess how effective the vaccine is. Success with a trial of this nature would lead to bypassing the normal Stage III in the research process, which in turn would lead to a vaccine being licenced more quickly. There are ethical considerations that people should consider and be aware of before they make the decision to take part.
In the summer, WHO (World Health Organisation) noted that they questioned if a challenge trial would truly speed up the vaccine effort, given that other efficacy trials had already begun. They have produced guidance on COVID-19 human challenge trials, which includes guidance on ethics and informed consent of the volunteers (a clear understanding of the facts, implications and consequences of an action). If a person has volunteered for a trial of this nature without coercion, they are making the choice freely. These people risk unknown hazards that lie beyond sight and possible long term consequences.
The Risk of Harm:
For any HCT, the foreseeable risks to the participant must be assessed against the overall benefit to the subject or others. The greater the risk, the greater the benefit must be to society. For a phase III trial a large sample of participants is required, as many of them may not end up being infected by the virus. However with an HCT, there will be a guaranteed rate of infection, which saves time and money.
As the 18-30 age group has the lowest rate of mortality for COVID-19, it follows that it is a sensible choice to select this group to take part, however everyone should be cautious and remember the health care workers and people who were not expected to fall prey to the virus and have sadly now died or become extremely unwell. A young man in his mid-twenties with no prior condition may be living well, but behind the scenes there may be the beginnings of an issue with his heart, liver or kidneys that typically may not manifest for many years unless he is exposed to an illness that would shine a light on it. Some people who have developed COVID-19 have now also developed the extremely troubling “long term covid”, only time will reveal the consequences of this. Informed consent becomes much harder if no one knows the true extent of the side effects.
Those who do take part in a trial like this in the coming months despite the concerns and unknowns, should be clear of the possible consequences for them, of taking part in a trial of this nature.
Blog by Stephanie Spencer