Effectiveness of Monovalent and Bivalent mRNA Vaccines in Preventing COVID-19–Associated Emergency Department and Urgent Care Encounters Among Children Aged 6 Months–5 Years — VISION Network, United States, July 2022–June 2023
Ruth Link‐Gelles, Allison Avrich Ciesla, Elizabeth Rowley, Nicola P. Klein, Allison L. Naleway, Amanda B. Payne, Anupam B. Kharbanda, Karthik Natarajan, Malini B. DeSilva, Kristin Dascomb, Stephanie A. Irving, Ousseny Zerbo, Sarah E. Reese, Ryan E. Wiegand, Morgan Najdowski, Toan C. Ong, Suchitra Rao, Melissa S. Stockwell, Ashley Stephens, Kristin Goddard, Yessica C. Martinez, Zachary A. Weber, Bruce Fireman, John Hansen, Julius Timbol, Shaun J. Grannis, Michelle A. Barron, Peter J. Embí, Sarah W. Ball, Manjusha Gaglani, Nancy Grisel, Julie Arndorfer, Mark W. Tenforde, Katherine E. Fleming-Dutra
Abstract
On June 19, 2022, the original monovalent mRNA COVID-19 vaccines were approved as a primary series for children aged 6 months-4 years (Pfizer-BioNTech) and 6 months-5 years (Moderna) based on safety, immunobridging, and limited efficacy data from clinical trials. On December 9, 2022, CDC expanded recommendations for use of updated bivalent vaccines to children aged ≥6 months. mRNA COVID-19 vaccine effectiveness (VE) against emergency department or urgent care (ED/UC) encounters was evaluated within the VISION Network during July 4, 2022-June 17, 2023, among children with COVID-19-like illness aged 6 months-5 years. Among children aged 6 months-5 years who received molecular SARS-CoV-2 testing during August 1, 2022-June 17, 2023, VE of 2 monovalent Moderna doses against ED/UC encounters was 29% (95% CI = 12%-42%) ≥14 days after dose 2 (median = 100 days after dose 2; IQR = 63-155 days). Among children aged 6 months-4 years with a COVID-19-like illness who received molecular testing during September 19, 2022-June 17, 2023, VE of 3 monovalent Pfizer-BioNTech doses was 43% (95% CI = 17%-61%) ≥14 days after dose 3 (median = 75 days after dose 3; IQR = 40-139 days). Effectiveness of ≥1 bivalent dose, comparing children with at least a complete primary series and ≥1 bivalent dose to unvaccinated children, irrespective of vaccine manufacturer, was 80% (95% CI = 42%-96%) among children aged 6 months-5 years a median of 58 days (IQR = 32-83 days) after the dose. All children should stay up to date with recommended COVID-19 vaccines, including initiation of COVID-19 vaccination immediately when they are eligible.