Table 3.
Association between non-genetic characteristics and IgA seroconversion among vaccinated Nicaraguan children.
| Variables | RV1 (n = 168) | RV5 (n = 68) | Both Vaccines (n = 236) | p-value b | |||
|---|---|---|---|---|---|---|---|
| No. enrolled children | Seroconversionan (%) | No. enrolled children | Seroconversion n (%) | No. enrolled children | Seroconversion n (%) | ||
| Sex | |||||||
| Female | 88 | 21 (24) | 27 | 10 (37) | 115 | 31 (27) | 0.60 |
| Male | 80 | 17 (21) | 41 | 12 (29) | 121 | 29 (24) | |
| IgA status pre-vaccination | |||||||
| Seropositivec | 94 | 18 (19) | 27 | 9 (33) | 121 | 27 (22) | 0.26 |
| Seronegative | 74 | 20 (27) | 41 | 13 (32) | 115 | 33(29) | |
| Breast feeding | |||||||
| Non-Exclusive | 89 | 18 (20) | 53 | 18 (34) | 142 | 36 (25) | 0.93 |
| Exclusive | 79 | 20 (25) | 10 | 3 (30) | 89 | 23 (26) | |
| IgA titers in breast-milk d | |||||||
| ≤ 160 | 28 | 5 (18) | 42 | 10 (24) | 70 | 15 (21) | 0.411 |
| 320–639 | 11 | 2 (18) | 15 | 7 (47)e | 26 | 9 (35) | |
| 640 ≤ | 19 | 3 (16) | 10 | 4 (40)f | 29 | 7 (24) | |
| Calprotectin (ug/ml) g | |||||||
| 2.3 to 3.8 (25th) | 7 | 1 (14) | 16 | 6 (38) | 23 | 7 (30) | 0.53 |
| 3.9 to 4.7 (50th) | 18 | 1 (6) | 29 | 8 (28) | 47 | 9 (19) | |
| 4.8 to 9.7 (75th) | 7 | 0 (0) | 15 | 6 (40) | 22 | 6 (27) | |
aSeroconversion defined as a four-fold increase in serum IgA titers 28 days post-vaccination with RV1 or RV5.
bChi-square test of equal proportions for both vaccines combined
cSeropositivity was defined as a titer of IgA ≥80 or ≥100 in RV1 or RV5, respectively.
dA subset of 58 RV1 and 67 RV5 mothers provided breast milk for IgA analysis. Titer categories were arbitrary defined.
eOR = 2.8, CI: 0.81–9.66, after comparing ≤160 vs 320–639 categories, respectively
fOR = 2.1, 0.50–9.10, after comparing ≤160 vs 640≤ categories, respectively
gA subset of 32 RV1 and 60 RV5 children provided stool samples for calprotectin analysis. Stratification of calprotectin concentration represent percentiles.
Abbreviations: RV1 = monovalent rotavirus vaccine; RV5 = pentavalent rotavirus vacci.