Originally posted 11 Sept 20
Here is an excerpt:
Is the process for clinical trials of vaccines different from the process for drug or device trials?
Mostly no. The principles, design, and basic structure of a vaccine trial are more or less the same as for a trial for a new medication. The research ethics considerations are also similar.
The big difference between the two is that the participants in a preventive vaccine trial are, by and large, healthy people — or at least they are people who don’t have the illness for which the agent being tested might be effective. That significantly heightens the risk-benefit calculus for the participants.
Of course, some people in a Covid-19 vaccine trial could personally benefit if they live in communities with a lot of Covid-19. But even then, they might never get it. That’s very different than a trial in which individuals have a condition, say melanoma or malignant hypertension, and they are taking part in a trial of a therapy that could improve or even cure their condition.
Does that affect when a company might stop a trial?
In every clinical trial, the data and safety monitoring board takes routine and prescheduled looks at the accumulated data. They are checking mainly for two things: signals of harm and evidence of effectiveness.
These boards will recommend stopping a trial if they see a signal of concern or harm. They may do the same thing if they see solid evidence that people in the active arm of the trial are doing far better than those in the control arm.
In both cases, the action is taken on behalf of those participating in the trial. But it is also taken to advance the interests of people who would get this intervention if it was to be made publicly available.
The current situation with AstraZeneca involves a signal of concern. The company’s first obligation is to the participants in the trial. It cannot ethically proceed with the trial if there is reason for concern, even based on the experience of one participant.