Experts likely to drop placebo arm from trials in policy shift

The government is deliberating a significant change in rules governing clinical trials of Covid-19 vaccines by doing away with the placebo arm as part of clinical trials.

Experts are discussing whether administering a placebo to volunteers in a clinical trial is necessary in order to assess the safety and efficacy of the vaccines, people in the know told ET.

They are also looking to see if a so-called comparator or a comparable product, in this case an alternative vaccine, should be administered to volunteers instead of a placebo.


The new policy change, which is likely to be announced soon, will have to be followed by vaccine makers like Gennova Biopharmaceuticals and others which are yet to start their phase-3 clinical trials.

“A revision in the rules of mid to late-stage clinical trials (phase 2/3) is likely to be brought in. The experts are mulling whether there should be a comparator or not to understand the safety and efficacy of the vaccine. They propose to do away with the placebo arm,” said a senior government official.

One of the significant reasons cited by an official for the proposed change is that a participant in such trials will lose out on a vaccine if the person is placed in the placebo arm.

Amar Jesani, editor, Indian Journal of Medical Ethics, favoured the proposed changes. “A placebo arm was justified when there was no vaccine available. But depriving a person from the currently available standard of care is unethical”.

“In a trial 50% of the participants get vaccines while the rest who are in a placebo arm do not get any. Why should one join a trial when a vaccine is easily available,” Jesani added.

Vaccines developed for Covid are based on a different platform technology, making a comparison difficult. For example, Gennova which is working on a mRNA based platform should ideally be compared with an approved vaccine from the same platform technology.