Moderna vaccine up to 88% effective against COVID in kids 6 to 11 yearsEstimated effectiveness of the Moderna COVID-19 vaccine against infection in children 6 to 11 years old was 88% at least 14 days after the first dose amid the Delta variant surge, before the emergence of Omicron, finds an interim analysis from a phase 2/3 clinical trial.Vanderbilt University investigators led the study, which was conducted at 79 US and 8 Canadian sites and published yesterday in the New England Journal of Medicine (NEJM).In part 1, the team randomly assigned 751 children aged 6 to 11 to receive 50- or 100-microgram (μg) doses of the vaccine from March to August 2021.
After evaluation of safety and immunogenicity, the 50-μg dose was chosen for part 2 of the trial.In part 2, 4,016 children were randomly assigned in a 3:1 ratio to receive either two 50-μg vaccine doses or a placebo 28 days apart.
Follow-up was a median of 82 days.The vaccine was tied to primarily low-grade, limited adverse events such as injection-site pain, headache, and fatigue.
No serious adverse events, multisystem inflammatory syndrome in children, myocarditis, or pericarditis were reported.One month after dose two, concentrations of SARS-CoV-2 neutralizing antibodies in children given a 50-μg dose were more than twice as high as those in adults 18 to 25 years given a 100-μg dose in a related phase 3 trial.