Ethical Considerations for Unblinding and Vaccinating COVID-19 Vaccine Trial Placebo Group Participants

The Pfizer-BioNTech, Moderna, and Johnson & Johnson COVID-19 vaccinations have been approved under “Emergency Use Authorization” by the United States Food and Drug Administration (FDA). Other vaccines, such as the Sputnik V and AstraZeneca vaccines, have begun to be distributed in other nations around the world after the publication of promising efficacy results. Multiple more vaccine candidates are likely to follow, which will still require safety and efficacy testing. As vaccines have been distributed in a tiered fashion to the public, there has been discussion and disagreement regarding the matter of vaccination of placebo groups from the past or upcoming trials (1). It has been argued that only trial participants (placebo group) who would be otherwise offered the vaccine outside of the trial [i.e., high risk participants or healthcare workers (HCWs)] should be unblinded and given the vaccine, while all other participants should remain blinded (2, 3). We argue that, once proven efficacious, vaccine makers and researchers have an ethical obligation to unblind the placebo groups of COVID-19 vaccine trials and offer them vaccine, based on the four principles of medical ethics.