Preliminary Estimates of Effectiveness of Monovalent mRNA Vaccines in Preventing Symptomatic SARS-CoV-2 Infection Among Children Aged 3–5 Years — Increasing Community Access to Testing Program, United States, July 2022–February 2023
Katherine E. Fleming-Dutra, Allison Avrich Ciesla, Lauren E. Roper, Zachary Smith, Joseph D. Miller, Emma K. Accorsi, Jennifer R. Verani, Nong Shang, Gordana Derado, Ryan E. Wiegand, Tamara Pilishvili, Amadea Britton, Ruth Link‐Gelles
Abstract
for whom a nucleic acid amplification test (NAAT) was performed during August 1, 2022-February 5, 2023, VE of 2 monovalent Moderna doses (complete primary series) against symptomatic infection was 60% (95% CI = 49% to 68%) 2 weeks-2 months after receipt of the second dose and 36% (95% CI = 15% to 52%) 3-4 months after receipt of the second dose. Among symptomatic children aged 3-4 years with NAATs performed during September 19, 2022-February 5, 2023, VE of 3 monovalent Pfizer-BioNTech doses (complete primary series) against symptomatic infection was 31% (95% CI = 7% to 49%) 2 weeks-4 months after receipt of the third dose; statistical power was not sufficient to estimate VE stratified by time since receipt of the third dose. Complete monovalent Moderna and Pfizer-BioNTech primary series vaccination provides protection for children aged 3-5 and 3-4 years, respectively, against symptomatic infection for at least the first 4 months after vaccination. CDC expanded recommendations for use of updated bivalent vaccines to children aged ≥6 months on December 9, 2022 (6), which might provide increased protection against currently circulating SARS-CoV-2 variants (7,8). Children should stay up to date with recommended COVID-19 vaccines, including completing the primary series; those who are eligible should receive a bivalent vaccine dose.