Oral polio vaccine response in the MAL-ED birth cohort study: Considerations for polio eradication strategies

Figures

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  Fig. 1. Child samples selected for OPV response study. Blood sample collection from each child was scheduled at seven and 15 months of age. All blood samples with sufficient volume were tested for poliovirus serotype 1, 2, and 3 serum neutralizing antibody assays. Children administered inactivated poliovirus vaccines were excluded, all of whom were from the MAL-ED cohort study site in South Africa. Blood samples collected from children receiving less than three documented doses of oral poliovirus vaccine prior to the date of blood collection were also excluded. The 2541 samples included in this analysis represent 1449 children from seven MAL-ED cohort study sites. 1092 of 1449 children (75%) contributed samples at both time points.

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  Fig. 2a. Poliovirus serotype 1 neutralization titer distributions by site and scheduled month of blood collection. Site locations; Dhaka, Bangladesh (BGD), Foratleza, Brazil (BRF); Vellore, India (INV); Bhaktapur, Nepal (NEB); Loreto, Peru (PEL); Naushero Feroze, Pakistan (PKN); Haydom, Tanzania (TZH).

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  Fig. 2b. Poliovirus serotype 3 neutralization titer distributions by site and scheduled month of blood collection. Site locations; Dhaka, Bangladesh (BGD), Foratleza, Brazil (BRF); Vellore, India (INV); Bhaktapur, Nepal (NEB); Loreto, Peru (PEL); Naushero Feroze, Pakistan (PKN); Haydom, Tanzania (TZH).

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  Fig. 3a. Polio serotype 1 titers by enteropathogen detection scores (bacteria, parasites, viruses, all combined) computed for diarrheal, non-diarrheal and all stools combined among children receiving at least 3 OPV doses at the scheduled 7 month blood draw. Scatter plots include penalized B-splines (10 knots) and 95% confidence intervals. A chi-square test was evaluated for each scatter plot comparing the percent of children who failed to seroconvert in a high vs. low enteropathogen score group where high was defined as the approximate 75th percentile of the enteropathogen score (i.e., 1.0, 0.33, 0.15, and 1.25 for Bacteria, Parasite, Virus and All Pathogens Scores, respectively); † indicates p<0.05; †† indicates p<0.01.

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  Fig. 3b. Polio serotype 3 titers by enteropathogen detection scores (bacteria, parasites, viruses, all combined) computed for diarrheal, non-diarrheal and all stools combined among children receiving at least 3 OPV doses at the scheduled 7 month blood draw. Scatter plots include penalized B-splines (10 knots) and 95% confidence intervals. A chi-square test was evaluated for each scatter plot comparing the percent of children who failed to seroconvert in a high vs. low enteropathogen score group where high was defined as the approximate 75th percentile of the enteropathogen score (i.e., 1.0, 0.33, 0.15, and 1.25 for Bacteria, Parasite, Virus and All Pathogens Scores, respectively); † indicates p < 0.05; †† indicates p < 0.01.

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  Fig. 4. Serotype 1 and 3 titer distributions and confidence intervals for WAMI component scores at 15 months. Penalized B-splines were fit using 10 knots. Pearson correlation coefficients (denoted r) are reported in the lower right corner of each scatter plot (all correlations have p < 0.0001 for the test of r being different from 0, except correlations with Maternal Education, which were not significant)

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  Fig. 5. Distribution of WAMI component and HOME Cleanliness scores by site. Sites are sorted by highest to lowest overall WAMI score. Symbol descriptions: the box represents the Interquartile Range (25th to 75th percentile); the black plus (+) is the mean; the median is indicated by the box notch; lines extending from the box with hash marks are 1.5 times the interquartile values; and circles represent potential outliers.