Fig. 1: Heterogeneity in immunity levels in childbearing-age women from 2013 to 2024.

A Measured antibody concentration in the years 2013–2015 (T1) and 2021–2024 (T2). Coloured points represent each individual’s antibody concentrations (n = 772). Each black point, along with an error bar, indicates the bimonthly mean antibody concentration and its 95% confidence interval. B Summary of log-concentration distribution in the years of 2013–2015 (n = 529) and 2021–2024 (n = 396). The dotted lines show the mean value of the log-concentration distribution; the black points with error bars in the inset panel show mean log-concentration and its 95% confidence interval. C The proportion of susceptible individuals aged 20–24 (n = 306), 25–34 (n = 484), and 35–49 years (n = 135) in 2013–2015 and 2021–2024 are shown by the points with error bars. Each point with error bar is the estimated mean percent susceptible and corresponding 95% confidence intervals. D Transplacental transfer of maternal antibodies. Grey points show the measured transplacental transfer ratio of log-concentrations (main panel), individual log-concentration (left subpanel) and the consistency between maternal and neonatal log-concentration (right subpanel), respectively. In the main panel, the blue line denotes the mean transplacental transfer ratio as a function of log-concentration level in birthing women using loess fit regression. In the left subpanel, observed maternal (mAb) and neonatal (nAb) mean log-concentrations are shown as blue horizontal lines, while in the right subpanel the blue line represents the regression mean. In both the main panel and right subpanel, the shaded areas denote 95% confidence intervals.