mRNA-1273 vaccine effectiveness against symptomatic SARS-CoV-2 infection and COVID-19-related hospitalization in children aged 6 months to 5 years

Abstract

ABSTRACTImportanceData on mRNA-1273 (Moderna) vaccine effectiveness in children aged 6 months to 5 years are limited.ObjectiveTo assess mRNA-1273 vaccine effectiveness against symptomatic SARS-CoV-2 infection and COVID-19-related hospitalization among children aged 6 months to 5 years.Design, Setting, and ParticipantsA test-negative study using linked health administrative data in Ontario, Canada. Participants included symptomatic children aged 6 months to 5 years who were tested by RT-PCR.ExposuresmRNA-1273 vaccination.Main Outcomes and MeasuresSymptomatic SARS-CoV-2 infection and COVID-19-related hospitalization.ResultsWe included 3467 test-negative controls and 572 test-positive cases. Receipt of mRNA-1273 was associated with reduced symptomatic SARS-CoV-2 infection (VE=90%; 95%CI: 53, 99%) and COVID-19-related hospitalization (VE=82%; 95%CI: 4, 99%) ≥7 days after the second dose.Conclusions and RelevanceOur findings suggest mRNA-1273 vaccine effectiveness is initially strong against symptomatic SARS-CoV-2 infection and hospitalization in children aged 6 months to 5 years. Further research is needed to understand long-term effectiveness and the need for booster doses.