Maternal influenza vaccination elicits transplacental transfer of hemagglutinin stem-specific IgG

Hemagglutinin (HA) glycoprotein is the dominant antigen of current influenza vaccines and antigenic drift requires a seasonal vaccine. The stem region HA conserved therefore promising target for universal Understanding specific response crucial in vaccine development. We hypothesize that maternal vaccination with would result boost antibodies higher concentrations neonatal cord blood. Two parallel prospective cohorts pregnant women were recruited mid-trimester before (n=15) 3rd trimester after (n=18). Maternal plasma assessed 15 participants pre post 2019 18 prenatally vaccinated paired blood samples. Enzyme linked immunosorbent assay (ELISA) detected IgG subclass titers antigens recombinant antigen. used Wilcoxon signed rank test to assess antibody titer differences between umbilical plasma. boosted (log2 threshold 14.5, (95% CI 13.8-15.2) versus (v) 16.0 15.2-16.8) post-vaccine, P = 0.004) more robustly than all (18.6 v 19.4 0.008). post-vaccine IgG1 (9.0 7.7, 0.001) IgG3 (8.2 7.1, subclasses compared other subclasses. While similar (P 0.09), concentrated (16.0 15.4, 0.002) which was dominated by (10.1 9.6, 0.004). generates This dominant. this cohort. These data support as future vaccination.View Large Image Figure ViewerDownload Hi-res image Download (PPT)