Related Experiment Video
Updated: Jul 8, 2025
Contact-Free Co-Culture Model for the Study of Innate Immune Cell Activation During Respiratory Virus Infection
Published on: February 28, 2021
Innate and Adaptive Cell-Mediated Immune Responses to a COVID-19 mRNA Vaccine in Young Children
Adriana Weinberg1,2,3, Michael J Johnson1, Krystle Garth1
1Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
Insights
COVID-19 mRNA vaccines in children aged 6 to 60 months induce robust cell-mediated immunity (CMI), encompassing both adaptive and innate immune responses. These vaccine-elicited CMI responses were significant in vaccinated children.
Area of Science:
- Immunology
- Vaccinology
- Pediatrics
Background:
- Limited data exists on cell-mediated immunity (CMI) following COVID-19 mRNA vaccination in young children.
- This study investigates adaptive and innate CMI in children aged 6 to 60 months post-vaccination.
Purpose of the Study:
- To assess the adaptive and innate cell-mediated immune responses to COVID-19 mRNA vaccines in children aged 6 to 60 months.
- To compare CMI responses in children after vaccination versus SARS-CoV-2 infection.
Main Methods:
- Blood samples were collected before and 1 month after the first mRNA vaccine dose from 29 children (mean age 28.5 months).
- Flow cytometry was used to measure adaptive and innate immune cell activation after ex vivo stimulation with SARS-CoV-2 spike peptides.
- Antibody levels and prior SARS-CoV-2 infection status were also assessed.
Main Results:
- Vaccination significantly increased activated conventional CD4+ T cells, γδ T cells, natural killer cells, monocytes, and conventional dendritic cells.
- These responses were generally higher post-vaccination compared to post-SARS-CoV-2 infection in children.
- No significant difference in CMI response fold increase was observed between previously infected and uninfected children.
Conclusions:
- COVID-19 mRNA vaccination in children aged 6 to 60 months elicits strong adaptive and innate cell-mediated immunity.
- The findings support the development of robust immune responses following mRNA vaccination in this pediatric age group.
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.
More Related Videos
09:03Rapid In Vivo Assessment of Adjuvant's Cytotoxic T Lymphocytes Generation Capabilities for Vaccine Development
Published on: June 19, 2018
09:37Detection of Polyfunctional T Cells in Children Vaccinated with Japanese Encephalitis Vaccine via the Flow Cytometry Technique
Published on: September 23, 2022
Related Concept Videos
01:21Introduction to Innate and Adaptive Immunity
Innate immunity is the body's natural, nonspecific defense system that acts quickly to protect against pathogens. It incorporates physical barriers like skin and mucous membranes and cellular elements such as phagocytes and natural killer cells. This part of our immune system provides an immediate,...
01:29Immune Response Against Viral Pathogens
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
01:22Development of Immunocompetence
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
01:40Cell-mediated Immune Responses
01:23Cells of the Adaptive Immune Response
01:51Vaccinations