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Table 2 Multivariate linear mixed-effects modelling of the combined IgG responses (measured as optical density (OD) values) to Plasmodium falciparum and Plasmodium vivax recombinant antigens

From: Quantification of the dynamics of antibody response to malaria to inform sero-surveillance in pregnant women

Variable PfAMA1 PfEBA175 PfMSP2 PfMSP3 PvAMA1 PfVAR2CSA
Fixed effectsa
 Age (years) 0.001 (− 0.006, 0.008) 0.007 (− 0.001, 0.015) 0.005 (− 0.001, 0.01) 0.001 (0.0001, 0.003) − 0.001 (− 0.002, 0.0004) 0.003 (− 0.0001, 0.007)
Gravidity       
 Primigravidae 0.064 (− 0.05, 0.179) − 0.017 (− 0.153, 0.118) 0.013 (− 0.075, 0.102) 0.004 (− 0.018, 0.027) − 0.005 (− 0.029, 0.02) − 0.012 (− 0.069, 0.046)
Intervention group       
 Chloroquine 0.054 (− 0.021, 0.13) 0.048 (− 0.041, 0.136) 0.009 (− 0.05, 0.067) − 0.003 (− 0.019, 0.013) 0.019 (0.002, 0.036) 0.031 (− 0.007, 0.069)
History of malaria
 Yes − 0.04 (− 0.116, 0.036) − 0.024 (− 0.113, 0.065) − 0.02 (− 0.08, 0.039) − 0.002 (− 0.018, 0.013) 0.012 (− 0.005, 0.028) − 0.014 (− 0.053, 0.024)
Average random effects for a woman
 Low immune
  Mean antibody levelb 0.31 (0.231, 0.388) 0.469 (0.373, 0.564) 0.704 (0.631, 0.777) 0.069 (0.048, 0.09) 0.095 (0.073, 0.117) 0.235 (0.189, 0.281)
  Gestation (weeks)c − 0.001 (− 0.002, 0.0001) − 0.002 (− 0.003, − 0.0004) − 0.003 (− 0.004, − 0.001) 0.00004 (− 0.001, 0.001) − 0.0003 (− 0.001, 0.0003) − 0.001 (− 0.002, 0.0004)
 High immune
  Mean antibody levelb 0.864 (0.67, 1.062) 1.076 (0.897, 1.264) 1.000 (0.893, 1.111) 0.603 (0.404, 0.808) 0.448 (0.283, 0.608) 0.634 (0.498, 0.766)
  Gestation (weeks)c − 0.0004 (− 0.006, 0.005) 0.0001 (− 0.005, 0.005) 0.001 (− 0.002, 0.005) − 0.006 (− 0.012, − 0.001) − 0.003 (− 0.008, 0.002) 0.002 (− 0.003, 0.006)
  1. Posterior medians (95% credible interval) for the fixed effects, population average intercept and population average slope parameters
  2. aFixed effects interpretation: change in mean antibody levels per year increase in age and difference in mean antibody levels for primigravidae vs. multigravida (reference group), chloroquine vs. placebo (reference group) and history vs. no history of malaria (reference group)
  3. bPopulation mean antibody levels for women of average age (25 years old), multigravida, in the placebo group and with no history of malaria
  4. cPopulation average change in antibody levels for a one week increase in gestation