The Ethical Dilemma of Continuing Ongoing COVID-19 Trials

The Ethical Dilemma of Continuing Ongoing COVID-19 Trials

Reported by James Kingsland of Medical News Today, Over the past few weeks, the Food and Drug Administration (FDA) have given emergency use authorization (EUA) to two COVID-19 vaccines, one by Pfizer-BioNtech and one by Moderna. As a result, in the coming months, millions of the most vulnerable people in the U.S. will receive a vaccine that protects them against the disease. This is good news, but it does pose an ethical dilemma for researchers conducting ongoing clinical trials of these and other COVID-19 vaccines. More than 180 candidate vaccines against the disease are in development, with at least 12 in phase 3 clinical trials.

According to guidance issued by the FDA in June 2020, in the event of a COVID-19 vaccine being judged safe and effective, there may be a case for “unblinding” trials and offering the vaccine to those who received the placebo. Given that the treatment options remain limited for anyone who develops a severe, life threatening case of COVID-19, it may be in the best interests of trial participants to receive one of the two proven vaccines as soon as possible.

Bioethicists at the National Institutes of Health (NIH) Clinical Center in Bethesda, MD, address these complex ethical issues in an opinion piece in the latest issue of the journal Science.

Benefits for society

The authors emphasize that vaccine researchers need to take other factors into consideration when they decide whether or not to continue trials as originally planned. They write that even if early results have found some vaccines to be safe and effective, continuing to conduct trials may bring further benefits for society.

In addition, some vaccines may be more effective than others at protecting particular groups, such as older people or those with comorbidities. “This highlights the potential social value of conducting additional trials after one or more vaccine candidates are found to be safe and efficacious,” they write.

Even after the FDA grant EUA to a vaccine, conducting further research may provide additional information and reassurance about its safety and efficacy before offering it to millions of people. 

Patients or participants?

Some commentators argue that once a clinical trial has gathered enough data to show that one arm of the trial is superior to the other — or superior to what is available outside the trial — it is no longer ethical to continue the research.

According to this view, the authors write, “researchers conducting clinical trials are obligated to treat participants consistent with their clinical interests,” and so it is no longer ethical to give participants a placebo once scientists have identified a safe and efficacious vaccine.

“We disagree,” they write. “This view fails to recognize that the obligations researchers have to their participants are distinct from the obligations that clinicians have to their patients.”

Acceptable Risks

The authors write, “In particular, codes and guidelines around the world permit researchers to expose participants in clinical trials, including vaccine trials, to some risks to collect socially valuable data that cannot be obtained in a less risky way.”

They list several social benefits that continuing trials may provide, including:

  • greater confidence in a vaccine’s efficacy
  • additional safety data, such as any uncommon or delayed side effects
  • an estimate of how long a vaccine’s protective effect lasts
  • insight into a vaccine’s impact on subgroups such as older people or those with preexisting conditions

Finally, they note that researchers who are designing new clinical trials might consider comparing their vaccine candidate with one of the authorized COVID-19 vaccines rather than a placebo.


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