The first children have been vaccinated in Moderna’s Phase 2/3 pediatric Covid-19 vaccine trial, the company announced Tuesday in a statement. The clinical trial, called the KidCOVE study, will enroll approximately 6,750 children in the US and Canada between the ages of 6 months and 11 years old. The trial is broken into two parts. In part one, different dosages of the vaccine are being tested on the children. Children between the ages of 6 months and 1 year old will receive two doses of the vaccine spaced about 28 days apart at either a 25 or a 50 or a 100 microgram level. Children between the ages of 2 and 11 will receive two doses of the vaccine spaced about 28 days apart at either a 50 or a 100 microgram level. The findings of part one will be used to determine which dose will be used in part two. For part two, the trial will expand to include children who are given a saline placebo, which does nothing. The children will be followed for 12 months after their second injection. Moderna is doing the tests to see if the vaccine protects children from getting sick if they come into contact with coronavirus, according to the clinical trial’s patient information website. “We are pleased to begin this Phase 2/3 study of mRNA-1273 in healthy children in the U.S. and Canada,” Moderna CEO Stéphane Bancel said in a press release. “This pediatric study will help us assess the potential safety and immunogenicity of our COVID-19 vaccine candidate in this important younger age population.” The study is being conducted in collaboration with the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, and the Biomedical Advanced Research and Development Authority at the US Department of Health and Human Services. Moderna is not the only Covid-19 vaccine currently being tested in children, as the Pfizer/BioNTech Covid-19 vaccine is being studied in children as well. Johnson & Johnson has announced plans to study the vaccine in adolescents, ages 12 to 18. In December, the US Food and Drug Administration authorized the emergency use of Moderna’s Covid-19 vaccine for adults and of Pfizer/BioNTech’s Covid-19 vaccine for people ages 16 and older. In February, the FDA authorized the emergency use of Johnson & Johnson’s vaccine for adults 18 and older.