Antigen-specific T cell responses in SARS-CoV-2 mRNA-vaccinated children

Jordan D Philpott; Jordan Miller; Brittany P Boribong; Saeina Charles; Jameson P Davis; Simon Kazimierczyk; Brittany Jimena; Maureen M Leonard; Wayne G Shreffler; Alessio Fasano; Lael M Yonker; Nitya Jain

doi:10.1016/j.xcrm.2023.101298

Antigen-specific T cell responses in SARS-CoV-2 mRNA-vaccinated children

Cell Rep Med. 2023 Dec 19;4(12):101298. doi: 10.1016/j.xcrm.2023.101298. Epub 2023 Nov 27.

Affiliations

¹ Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, 114 16(th) Street, Charlestown, MA 02129, USA.
² Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, 114 16(th) Street, Charlestown, MA 02129, USA; Pediatric Allergy and Immunology and Center for Immunology and Inflammatory Disease, Massachusetts General Hospital, 175 Cambridge Street, Boston, MA 02114, USA.
³ Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, 114 16(th) Street, Charlestown, MA 02129, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA.
⁴ Pediatric Allergy and Immunology and Center for Immunology and Inflammatory Disease, Massachusetts General Hospital, 175 Cambridge Street, Boston, MA 02114, USA.
⁵ Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, 114 16(th) Street, Charlestown, MA 02129, USA; Pediatric Allergy and Immunology and Center for Immunology and Inflammatory Disease, Massachusetts General Hospital, 175 Cambridge Street, Boston, MA 02114, USA. Electronic address: lyonker@mgh.harvard.edu.
⁶ Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, 114 16(th) Street, Charlestown, MA 02129, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Center for Computational and Integrative Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA. Electronic address: njain@mgh.harvard.edu.

Abstract

SARS-CoV-2 mRNA vaccines elicit humoral responses in children that are comparable to those in adults. However, early-life T cell responses are distinct from adult ones, and questions remain about the nature and kinetics of mRNA vaccine-induced T cell responses in children. We report that Pfizer BNT162b2 mRNA vaccination elicits a significant antigen-specific CD4⁺ T cell response in the ≥12-year-old cohort. This response is weaker in magnitude in the 5- to 11-year-old cohort and is not improved by a higher vaccine dose (Moderna mRNA1273, 100 μg), suggesting distinct developmental programming that may underscore early-life T cell immunity. Increased effector phenotypes of antigen-specific T cells in younger children correspond with elevated anti-receptor binding domain antibody levels, albeit at the cost of memory generation. These studies highlight aspects of age-specific adaptive immune responses and the need for careful consideration of priming conditions including vaccine dose and adjuvant in the pediatric population.

Keywords: T cell immunity; early life immunity; mRNA vaccine; pediatric COVID-19.

MeSH terms

Adult
BNT162 Vaccine
COVID-19* / prevention & control
Child
Child, Preschool
Humans
RNA, Messenger / genetics
SARS-CoV-2* / genetics
T-Lymphocytes

Substances

BNT162 Vaccine
RNA, Messenger