RT Journal Article SR Electronic T1 Payment of COVID-19 challenge trials: underpayment is a bigger worry than overpayment JF Journal of Medical Ethics JO J Med Ethics FD BMJ Publishing Group Ltd and Institute of Medical Ethics SP medethics-2020-106901 DO 10.1136/medethics-2020-106901 A1 Jennifer Blumenthal-Barby A1 Peter Ubel YR 2020 UL http://jme.bmj.com/content/early/2020/10/11/medethics-2020-106901.abstract AB