Moderna’s coronavirus vaccine is safe and effective at preventing Covid-19 in children aged six to 11, according to a peer reviewed study published in the New England Journal of Medicine on Wednesday, as the Food and Drug Administration considers expanding access to the shots for younger children.
Two doses of Moderna’s Covid-19 vaccine produced a strong immune response in line with adults ages 18 to 25 years old, data from the company’s U.S. and Canadian trial showed.
The trial evaluated the effect of two 50 μg (micrograms) doses of the vaccine—half the strength used for adults—given 28 days apart in nearly 3,000 children aged between six and 11.
The first shot had an estimated efficacy of 88% at preventing Covid-19 illness after at least 14 days according, the study found, dropping to around 63% for asymptomatic infections.
The study found the vaccine to have an “acceptable safety profile” among children, with most side effects mild and “transient.”
Fatigue, headaches and injection-site pain were the most commonly reported side effects, the researchers said.
WHAT WE DON’T KNOW
Efficacy after two shots and against omicron. The low number of Covid-19 cases among double vaccinated participants meant the researchers were unable to evaluate efficacy after two doses. The study was also conducted at a time the delta variant was dominant, meaning the shots have not been tested against omicron.
WHAT TO WATCH FOR
The FDA. Moderna has already asked the FDA for emergency authorization to use its shot in children ages six to 11 years and the regulator is expected to convene a panel of experts in the coming months. The shot has already been cleared for use in this age group in Australia, Canada, the U.K. and the EU.
Moderna is also seeking emergency authorization for its Covid-19 vaccine in children as young as six months after its clinical trial found two low doses—a quarter that used in adults and half that of children ages six to 11—were safe and generated a “robust” immune response. If approved, the shot will be the first available to U.S. kids under the age of five.
By Robert Hart, Forbes Staff