Pfizer Breaks Common Practice by Not Testing Transmission Defense: Epidemiologist

In light of the recent admission by Pfizer that its COVID-19 vaccine was not tested on preventing transmission before release, NTD spoke to Dr. Paul Alexander, an epidemiologist and former senior adviser to the U.S. Department of Health and Human Services (HHS). Alexander said that it is not common practice for pharmaceutical companies not to test vaccines for effectiveness in preventing transmission.