AstraZeneca defends dosing error in COVID-19 vaccine trial

Mene Pangalos, AstraZeneca’s executive vice president for biopharmaceuticals research and development, responded to criticism the company failed to issue sufficient information about a clinical trial of its COVID-19 vaccine. Some researchers say AstraZeneca failed to provide key data from its trial results, such as the number of infections that occurred across patient groups, based on age and severity of disease. AstraZeneca has stated that no patients receiving the vaccine developed severe disease or required hospitalization. Pangalos also acknowledged questions about the vaccine’s 90% effectiveness in a group of patients who erroneously received a lower dose than intended. The dosing error was identified after a trial investigator found that participants did not have as much of an inflammatory response to the dose. After researchers examined their vaccine supply, they determined they miscalculated the dose, according to Pangalos. AstraZeneca and Oxford informed U.S., U.K., and E.U. regulators and revised the study design to include the half-dose group in their analysis. Oxford researchers say the lower dose may have been more effective because it more accurately indicates the natural immune response to viruses, but additional investigations would need to be done to confirm the findings