Upregulation of TGF-beta 1 in neonates of mothers receiving Influenza A (H1N1) vaccination during pregnancy

Background: Influenza vaccination of pregnant women is generally considered safe,but the effects on the immune system of the unborn child are unknown.Objectives: Our primary objective was to explore differences in cytokine and chemokine levels in nasal mucosal lining fluid in neonates of mothers vaccinated during or after pregnancy. Method: IFN-c, IL-1b, IL-2, -4, -5, -10, - 12p70, -13, -17, TNF-a, IL-8, eotaxin-1,eotaxin-3, IP-10, MCP-1, MCP-4, MDC, MIP-1b, TGF-b1 and TARC were quantified in nasal mucosal lining fluid in neonates of mothers receiving Influenza A (H1N1v) vaccine during (n = 52) or after pregnancy (n = 118) in our unselected Copenhagen Prospective Study on Asthma in Childhood 2010 birth-cohort. Result: Neonates of mothers vaccinated during pregnancy showed a significant up-regulation of the immune-regulatory TGF-b1 (P = 0.0004), significant down regulation (P < 0.05) of TARC, IL-5, )8, )10, )12p70, eotaxin-1, MDC, IFN-c and non-significant down regulation of nearly all other mediators except for MCP-4,IL-17, eotaxin-3 compared to neonates of mothers vaccinated after pregnancy.Results are adjusted for season; airway colonization S. pneumoniae, H. influenzae, M.catarrhalis, and S. aureus; older siblings; furred animals in home; smoking during 3rd trimester; and mothers’ atopic disease. Conclusion: These findings suggest that Influenza A (H1N1) vaccination during pregnancy affects the mucosal immune competence of the unborn child. The up-regulation of TGF-b1 and down-regulation of nearly all essential contributors to protective immunity reflect an imprinting suggestive of immune inhibition that may affect the neonates’ ability to combat respiratory tract infections.