Thanks for your comment, this is my first post but I have been reading LessWrong and adjacent sites for 6+ years, so I'm not unfamiliar with the rationalist community.
I don't think I have much to add beyond the pitch in the original post. This is an opportunity to help improve reasoning and decision-making in real-world institutions with significant influence. By participating you get access to training materials used to teach reasoning evaluation in such institutions, which may be of intrinsic methodological interest. Further, by completing the training you may learn new skills that you can apply to improve your own reasoning.
It is also an opportunity to benchmark your own reasoning evaluation skills against others: we will be sending out such feedback once the study is complete, and are currently looking at ways to incorporate benchmarking into the training itself.
Appreciate your comment - we are aware of that and this is just one of several recruitment avenues we are pursuing.
I ran this by an epidemiologist friend and they pointed out that SARS-CoV-2 is mutating fairly quickly, so wide deployment of low-effectiveness vaccines (possibly including this one) would encourage the emergence and spread of vaccine-resistant strains of the virus.
This might become a big problem because vaccines are being rolled out whilst there is a lot of the virus circulating in the community.