Objective: To define changes in cellular and transcriptional immune profiles induced by routine vaccinations in infants.
Methods: We evaluated 47 healthy infants during routine vaccinations: 2 mo (n=24), 6 mo (n=16) and 12mo (n=7). Peripheral blood was collected on day (d) 0 (pre-vaccination), d7 and d30 post-vaccination for analysis of: a) immune cell populations by flow cytometry and b) immune genes transcriptome with microarrays.
Results: Flow: In 2 mo there was a significant increase on d7 of absolute numbers of monocytes; p<0.05, and on d30 of total, naïve and transitional B cells, and plasma cells, as well as T follicular helper (Tfh) cells and subsets (Tfh1, Tfh2 and Tfh17); p<0.01. In 12 mo on d30 we observed significant increases in memory B cells, plasmablasts, and Tfh cells and subsets; p<0.01.
Conclusion: 2 mo infants demonstrated a robust cellular and transcriptional immune response after vaccination. While 6 and 12 mo infants also showed significant overexpression of immune–related genes after vaccination, their responses were less significant, suggesting age-dependent differences likely related to the development of the immune system early in life.
R. Giacomelli Cao,
B. Smith, None
S. Heinonen, None
S. Mertz, None
F. Ye, None
V. Best, None
A. Mejias, Janssen: Grant Investigator and Scientific Advisor , Consulting fee and Research grant
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