Moderna is set to ask the FDA for emergency-use authorization for its COVID-19 vaccine to be given to children under 6. The Cambridge, Massachusetts-based biotech said trials had shown its jab produced protective antibodies in babies, toddlers, and young children and helped prevent infection. Moderna wants the under-6es to be offered two 25-microgram doses of its vaccine, about a quarter of the level given to adults. It is also asking to have larger doses approved for older children and teenagers. Pfizer has a vaccine approved for children over the age of 5.