To assess SARS-CoV-2 S-protein–specific T-cell–mediated immune responses in pediatric patients following mRNA-1273 vaccination, highlighting the importance of T-cell responses in COVID-19 protection.
Key Findings:
mRNA-1273 induced robust S-protein–specific CD4+ T-cell responses with a Th1-biased profile at day 43 and day 209, indicating strong immune activation.
CD8+ T-cell responses were less frequently detected in children under 5 years and undetectable in those under 2 years, suggesting age-related differences.
Higher frequencies of S-specific polyfunctional CD4+ T cells were observed at day 43 compared to placebo, with detectable levels at day 209, indicating sustained immune response.
Correlation between Th1 CD4+ responses and neutralizing antibodies was noted across age groups, suggesting a link between T-cell and antibody responses.
Interpretation:
The 2-dose mRNA-1273 primary series elicited durable Th1-biased CD4+ T-cell responses in children aged 6 months to 11 years, suggesting potential for long-term immunity against COVID-19.
Limitations:
Limited sample size with only 68 participants assessed for T-cell responses, which may affect the generalizability of the findings.
The study focused on a subset of participants, which may not represent the broader pediatric population, highlighting the need for further research.
Conclusion:
mRNA-1273 vaccination generates significant T-cell responses in young children, indicating its potential effectiveness against COVID-19, but further studies are needed to confirm long-term immunity.
by Christina A Rostad, James D Campbell, Grant C Paulsen, Sabine Schnyder Ghamloush, Wenqin Xu, Lingyi Zheng, M Juliana McElrath, Stephen C De Rosa, Bethany Girard, Rituparna Das, Evan J Anderson, C Buddy Creech, on behalf of the KidCOVE CMI Study Group
