Weekly Commentary: Human Challenge Trials As Strategic Move For COVID-19
Dr. Aaron Lerner 9 September 2020
We have a strategic interest to not only rush completion of testing and
production of our own in-house COVID-19 vaccine but also to achieve this in
a process which encourages the public to vaccinate.
The traditional method to test the efficacy of a vaccine is to vaccinate a
large sample with the vaccine and to vaccinate an equally large sample with
a placebo (control group)and then wait to see if there is a significant
difference in the propensity of the two samples to get infected.
A fundamentally different approach, "Human Challenge Trials", has been
proposed, according to which a sample of young healthy volunteers is
vaccinated and then EXPOSED to COVID-19. The choice of young volunteers is
because the risk they face if they do get infected is relatively small.
Since the volunteers are all exposed to COVID-19 at the start of the trial
the time required for the trial itself is dramatically shortened.
This has the double advantage that if the trial is a success that one can go
into commercial production much faster and if the trial fails to meet
expectations the scientist have a huge data base to study so that they can
determine what modifications may make their vaccine a success.
Even ignoring the above, Human Challenge Trials enjoy a crucial advantage in
convincing the public to vaccinate.
Let's walk through the numbers:
Assume that the odds of catching COVID-19 in a three month test period is
10% and the vaccine is 90% effective
The traditional testing method would publish the result that 1% of
participants who were vaccinated got infected while 10% of the control group
When the public sees these results they may ask if is it worth risking
unknown side effects just to reduce their odds by 9 points.
In contrast, the very same vaccine tested in Human Challenge Trials would
publish the result that the vaccine is 90% effective.
The public would interpret the results as meaning that the vaccine reduced
the odds of getting sick by 90 points and thus be considerably more willing
And with the street ever more skeptical, the need for intuitively strong
results is more important than ever.
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