Who made you the arbitrar of such things? You come across as someone engaging in bad faith.
There's a wealth of pre existing discussion on the ethics of trials and many many places about the globe that conduct trials, paid trials even. (eg: https://trials.linear.org.au/)
It's not difficult to access ethical philosphers discussing the matter, nor is it difficult to read essays by practicing epidemiologists and others.
Do you have a specific problem with paid clinical trials of novel vaccines?
2. If someone wants funding to do an experiment like the one described in the article I'll gladly throw $1,000 in the pot. So will many engineers. There's nothing you can do about this.
3. If you put this on a ballot, I'll vote to spend billions of dollars paying people to test medical treatments. This includes challenge trials. Small price for a large reward. I don't need any credentials to advocate for policies that benefit everyone.
btw I answered your question but you didn't answer mine: Are you a doctor or an ethicists or just a regular armchair philosopher?