Michael Nevradakis

July’s release of U.S. Food and Drug Administration (FDA) documents pertaining to the Emergency Use Authorization (EUA) granted to the Pfizer-BioNTech COVID-19 vaccine included reports of a significant number of participants who withdrew from the trials — and the reasons for these withdrawals.

In some instances, participants withdrew or were withdrawn from the trial due to serious adverse events, which again were usually determined to be “not related” to the vaccination.

In other instances, participants ended their participation in the trial over seemingly minor adverse events, such as injection site pain, without any further explanation provided in the documentation about other factors that may have been at play in the decision to withdraw.