Life course exposures continually shape antibody profile and risk of seroconversion to influenza

Bingyi Yang; Justin Lessler; Huachen Zhu; Chaoqiang Jiang; Jonathan M. Read; James A Hay; Kin On Kwok; Ruiyin Shen; Yi Guan; Steven Riley; Derek A.T. Cummings

All individuals had detectable titers (1:10) and 95.6% had protective titers (1:40) to at least one strain at baseline (Fig 2A-B) . The median of geometric mean titer (GMT) across all 21 tested strains was 14.3 [interquartile range (IQR), 11.4 to 25.9) at baseline and 36. 4 (IQR, 21.9 to 46.8) at follow-up (Fig. 2, A and B, and table S2) . GMTs of post-birth strains [18. 3; 95% confidence interval (CI), 18.0 to 18.7] were higher than that of pre-birth strains (9.6; 95% CI, 9.2 to 10 .0) at baseline ( Fig. 2A) . Participants had the highest titer to strains that were isolated within the first decade of their life (4.3 years; IQR, 2.0 to 6.9 years across strains) (fig. S1). GMTs of recent strains (12.0; 95% CI, 11.6 to 12.4) were lower than that of non-recent strains (18.7; 95% CI, 18.3 to 19 .0) at baseline, but were higher at follow-up [41.5 (95% CI, 39.7 to 43.3) for recent strains and 31.3 (95% CI, 30.7 to 31.9) for non-recent strains].