Moderna looks to test Covid-19 booster shots a year after initial vaccination

One of the boxes containing the Moderna COVID-19 vaccine is prepared to be shipped at the McKesson distribution center in Olive Branch, Mississippi, U.S. December 20, 2020. Paul Sancya | Reuters Moderna plans to test a booster shot of its Covid-19 vaccine a year after the initial two-dose immunization, as the duration of protection from the new vaccines is still unclear. The biotech company plans to start the trial in July, according to a corporate presentation at the JPMorgan Healthcare Conference on Monday. Staff at its clinical trial sites have…