The CDC’s own data showed that COVID-19 vaccines reduced serious disease and emergency department visits among both children and adults. But during Friday’s meeting, some ACIP officials questioned — without evidence — whether COVID-19 vaccines provide any advantage to the people who choose to get them. “What is the true efficacy and true benefits that these vaccines provide?” said Retsef Levi, an ACIP member and professor of operations management at the Massachusetts Institute of Technology. Other public health officials criticized the proposed rule change that would have required patients to obtain a prescription before receiving a COVID-19 vaccine. But Levi, who delivered a presentation that centered on the risks of COVID-19 vaccines, argued that current guidelines do not fully underscore the risk of adverse effects from vaccines.