Moderna on Tuesday said its COVID-19 vaccine was shown to be 100 percent effective in children between the ages of 12 and 17. No cases of COVID-19 were observed in clinical trial participants who received two doses of Moderna’s shot, the Massachusetts-based biotechnology company said in a press release. Moderna announced the results because it met its primary endpoint, which was a match to the vaccine’s ability to provoke an immune response seen in its trial among adults. The phase two/three trial of children also showed an efficacy of 93 percent in seronegative participants 14 days or more after the first dose using the Centers for Disease Control and Prevention’s (CDC) secondary definition, which requires one COVID-19 symptom and a nasal swab or saliva sample testing positive for the virus that causes the disease. The trial, dubbed TeenCOVE, enrolled more than 3,700 participants between the ages of 12 and 17 …