U.S. Health Officials Raise Concerns Over AstraZeneca Vaccine Data

In a surprising move, officials with the U.S. National Institute of Allergy and Infectious Diseases (NIAID) urged AstraZeneca to make sure it is providing the most recent data on the effectiveness of its coronavirus vaccine, reports the Wall Street Journal . This followed AstraZeneca's release of interim data from its U.S. trials, indicating the vaccine was 79 percent effective in preventing symptomatic infection. But NIAID said an independent monitoring board warned that the company's disclosures of the study results may have been founded on outdated evidence. The agency's response revives doubts about the vaccine's effectiveness, undermining newfound confidence in the product after issues were raised about associated blood clotting. It also further complicates AstraZeneca's timeline for emergency use authorization in the United States. NIAID did not in fact dispute the trial findings over the complication, but rather focused on unspecified information related to efficacy. Nevertheless, London School of Hygiene & Tropical Medicine Professor Stephen Evans called the decision by an independent trial-safety monitor to publicly challenge a company running a clinical trial "unprecedented."