1. Innate and Adaptive Cell-Mediated Immune Responses to a COVID-19 mRNA Vaccine in Young Children.
- Author
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Weinberg, Adriana, Johnson, Michael J, Garth, Krystle, Hsieh, Elena W Y, Kedl, Ross, Weiskopf, Daniela, Cassaday, Mattie, Rester, Cody, Cabrera-Martinez, Berenice, Baxter, Ryan M, and Levin, Myron J
- Subjects
COVID-19 pandemic ,VACCINATION of children ,MONONUCLEAR leukocytes ,COVID-19 vaccines ,KILLER cells ,BACTERIAL vaccines ,CHICKENPOX vaccines - Abstract
Background There is little information on cell-mediated immunity (CMI) to COVID-19 mRNA vaccines in children. We studied adaptive and innate CMI in vaccinated children aged 6 to 60 months. Methods Blood obtained from participants in a randomized placebo-controlled trial of an mRNA vaccine before and 1 month after the first dose was used for antibody measurements and CMI (flow cytometry). Results We enrolled 29 children with a mean age of 28.5 months (SD, 15.7). Antibody studies revealed that 10 participants were infected with SARS-CoV-2 prevaccination. Ex vivo stimulation of peripheral blood mononuclear cells with SARS-CoV-2 spike peptides showed significant increases pre- to postimmunization of activated conventional CD4+ and γδ T cells, natural killer cells, monocytes, and conventional dendritic cells but not mucosa-associated innate T cells. Conventional T-cell, monocyte, and conventional dendritic cell responses in children were higher immediately after vaccination than after SARS-CoV-2 infection. The fold increase in CMI pre- to postvaccination did not differ between children previously infected with SARS-CoV-2 and those uninfected. Conclusions Children aged 6 to 60 months who were vaccinated with a COVID-19 mRNA vaccine developed robust CMI responses, including adaptive and innate immunity. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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