U.S.-based Pfizer and its Germany-based partner BioNTech plan to give volunteers who received a placebo in its COVID-19 vaccine trial an option to receive a first dose of the vaccine by March 1, 2021. “All participants aged 16 years and older who courageously volunteered to help make a difference during this pandemic have the option to receive the investigational vaccine while continuing to be part of the clinical trial,” the companies said on their website. The U.S. Food and Drug Administration and a panel of its outside advisers have expressed concerns over Pfizer’s “unblinding” plan, saying it could make it harder to continue collecting data on safety and effectiveness needed to win full FDA approval of the vaccine. The companies said that trial participants who received the placebo will have two doses of the vaccine reserved for them within the study. Participants will be given the “Vaccine Transition Option,” the …