Epi info v 7

The data were entered in Epi Info V.7.2 and analysed using STATA V.16.1 (STATA Corp, Texas, USA). Categorical variables were compared by Pearson’s X² test. Seroprevalence of anti-PT IgG antibodies with 95% CIs was determined in infant–mother dyads. Geometric mean titres (GMTs) along with their 95% CI were calculated. Antibody titres were compared by two-sample t-test with unequal variances and two-sample Kolmogorov-Smirnov test. Statistical significance (p<0.05) is reported from the latter test. Placental transfer ratio of anti-PT IgG antibodies was defined as the ratio of cord to maternal geometric mean concentrations (GMCs). Univariate logistic regression was carried out with five variables classified as categorical variables (maternal age, vaccination status, maternal seropositivity for anti-PT antibodies, birth weight and gestational age of infant) to understand the influence on cord PT antibody titres >20 IU/mL. Unadjusted ORs were recorded and significant variables considered for multivariate logistic regression.