Moderna announced Tuesday it has dosed its first participant in a phase III clinical trial of a combination influenza and COVID-19 vaccine. This phase will evaluate the safety and efficacy of the combo vaccine compared to flu and COVID vaccines that are administered separately in two groups, one involving 4,000 adults aged 65 and older and another involving 4,000 adults between ages 50 and 64. In earlier Phase I/II clinical trials, data showed that the vaccine candidate achieved antibody levels similar or greater to the licensed standalone influenza vaccine and to Moderna's COVID vaccine