Infants with low vaccine antibody responses have altered innate cytokine response

Area of Science:

• Immunology
• Pediatrics
• Vaccinology

Background:

• A subset of infants (10%) demonstrates sub-protective antibody levels following routine pediatric vaccinations.
• These infants, termed low vaccine responders (LVRs), exhibit dysregulated innate and adaptive immune responses.
• Understanding the immunological basis of LVR is crucial for improving vaccine efficacy in this population.

Purpose of the Study:

• To investigate the immune cell response differences between LVR infants and normal vaccine responders (NVRs).
• To analyze the cytokine and chemokine profiles following stimulation with a Toll-like receptor 7/8 (TLR7/8) agonist.

Main Methods:

• Peripheral blood mononuclear cells (PBMCs) were isolated from LVR and NVR infants.
• PBMCs were stimulated with the TLR7/8 agonist R848.
• Cytokine levels (IFN-α, IL-12p70, IL-1β) and chemokine levels (CCL5/RANTES) were measured.

Main Results:

• LVR infants exhibited significantly lower levels of IFN-α, IL-12p70, and IL-1β upon R848 stimulation compared to NVR infants.
• Conversely, LVR infants showed higher levels of CCL5 (RANTES) production.
• These findings indicate a distinct cytokine and chemokine profile associated with low vaccine responsiveness.

Conclusions:

• LVR infants display an altered immune response characterized by reduced pro-inflammatory cytokines and increased CCL5 production.
• These immune differences may contribute to the sub-protective antibody levels observed in LVR infants.
• Further research into modulating these immune responses could enhance vaccine efficacy in LVR infants.