Figure 1.

Of 2,331 screened mother–infant pairs, 1,336 were eligible and 461 enrolled. A total of 365 singleton infants provided samples at 2months, but only 272 were included in the present analysis due to missing data. Of these, 239 had blood drawn at 6–8 months, and 126 at 12–18months of age. There were 121 infants with samples at all three time points. *Third blood draw was added after a secondary aim was funded, see Methods section.