Correlation plots for LASV IgG assessed by Spearman’s correlation (r) using linear regression.

Note: +/+ indicates seropositive from baseline. -/+ indicates seroconversion. The dotted black horizontal line indicates the line of efficient transfer (CMR = 1); IV- index value, an arbitrary antibody concentration unit based on manufacturer’s guide; mCMR- median cord maternal ratio; black and red lines are regression lines with the corresponding 95% confidence interval fitted to the regression line.</p

Linear regression analysis of the effect of maternal or neonatal characteristics on cord LASV IgG concentrations.

Linear regression analysis of the effect of maternal or neonatal characteristics on cord LASV IgG concentrations.</p

Bland-Altman plot showing agreement between maternal and cord Lassa and TT IgG antibodies.

Note: IV- index value; dotted black lines indicate limits of agreement (± 2sddiff); dotted red line indicates mean difference between maternal and cord concentrations; mdiff- mean difference; sddiff- standard deviation of differences.</p

Linear regression analysis of the effect of different factors on the transfer ratio of LASV IgG antibodies.

Linear regression analysis of the effect of different factors on the transfer ratio of LASV IgG antibodies.</p

Correlation plots between cord maternal ratio and maternal LASV and TT IgG concentrations assessed by Spearman’s correlation (r).

Note: mCMR- median cord maternal ratio; IV- index value, an arbitrary antibody concentration unit based on manufacturer’s guide; the dotted black horizontal line is the line of efficient transfer (CMR = 1); Log- natural logarithm; blue line is the regression line; grey shaded are the 95% confidence interval fitted to the regression line.</p

Factors associated with cord LASV IgG seronegativity (cord index value ≤ 0.9).

Factors associated with cord LASV IgG seronegativity (cord index value ≤ 0.9).</p

LASV IgG concentrations and cord maternal ratio by various maternal and neonate characteristics.

LASV IgG concentrations and cord maternal ratio by various maternal and neonate characteristics.</p

S4 Table -

(A) Linear regression analysis of the effect of different factors on the transfer ratio of LASV IgG antibodies amongst mothers with pre-existing antibodies. Note: β- regression coefficient showing change in cord LASV IgG concentration; CI- confidence interval; CMR- cord–maternal ratio; conc- concentration; IgG- immunoglobulin G; LASV- Lassa virus; LF- Lassa fever; N- total number of pregnant women included in analysis. a Adjusted for factors marginally significant in the univariate regression (crude p(B) Linear regression analysis of the effect of different factors on the transfer ratio of LASV IgG antibodies amongst mothers who seroconverted. Note: β- regression coefficient showing change in cord LASV IgG concentration; CI- confidence interval; CMR- cord–maternal ratio; conc- concentration; IgG- immunoglobulin G; LASV- Lassa virus; LF- Lassa fever; N- total number of pregnant women included in analysis. a Adjusted for factors marginally significant in the univariate regression (crude p(C) Linear regression analysis of the effect of different factors on the transfer ratio of LASV IgG antibodies amongst mothers who were seronegative. Note: β- regression coefficient showing change in cord LASV IgG concentration; CI- confidence interval; CMR- cord–maternal ratio; conc- concentration; IgG- immunoglobulin G; LASV- Lassa virus; LF- Lassa fever; N- total number of pregnant women included in analysis. a Adjusted for factors marginally significant in the univariate regression (crude p (DOCX)</p

TT IgG concentrations and cord maternal ratio by various maternal and neonate characteristics.

TT IgG concentrations and cord maternal ratio by various maternal and neonate characteristics.</p

Correlation between maternal and cord Lassa and TT IgG antibodies assessed by Spearman’s correlation (r).

Note: IV- index value; mCMR- median cord maternal ratio; black dotted horizontal line is line of seropositivity (LASV = 1.1, TT = 0.1IU/mL); blue line is the regression line; grey shaded are the 95% confidence interval fitted to the regression line.</p