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

The width of HAI titers above protective titer levels (nW 40 ) illustrated an increasing trend with age grows until approximately 15 years of age at the time of sample collection, peaking at 60.3% and 80.1% at baseline and follow-up, respectively (Fig. 3 , F and G). There was a more distinct drop in nW 40 among participants aged 50 years old [ratio to peak: 0.28 (95% CI, 0.25 to 0.29) and 0.46 (95% CI, 0.43 to 0.49) for baseline and follow-up, respectively], compared to the drop in nW 10 [ratio to peak: 0.78 (95% CI, 0.75 to 0.79) and 0.94 (95% CI, 0.90 to 0.97)] ( fig. S3 ). An uptick of widths among those older than 60 years was observed for both cutoffs ( Fig. 3 and fig. S3 ).