RT Journal Article SR Electronic T1 Why continuing uncertainties are no reason to postpone challenge trials for coronavirus vaccines JF Journal of Medical Ethics JO J Med Ethics FD BMJ Publishing Group Ltd and Institute of Medical Ethics SP 808 OP 812 DO 10.1136/medethics-2020-106501 VO 46 IS 12 A1 Steel, Robert A1 Buchak, Lara A1 Eyal, Nir YR 2020 UL http://jme.bmj.com/content/46/12/808.abstract AB To counter the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), some have proposed accelerating SARS-CoV-2 vaccine development through controlled human infection (or ‘challenge’) trials. These trials would involve the deliberate exposure of relatively few young, healthy volunteers to SARS-CoV-2. We defend this proposal against the charge that there is still too much uncertainty surrounding the risks of COVID-19 to responsibly run such a trial.