Table 3.
IgA antibody responses to different numbers of ETVAX antigens
|
24–59 months |
12–23 months |
6–11 months |
||||
|---|---|---|---|---|---|---|
| Vaccine (n=75) | Placebo (n=49) | Vaccine (n=54) | Placebo (n=40) | Vaccine (n=139) | Placebo (n=49) | |
| Mucosal IgA | ||||||
| Five antigens | 56 (75%) | 0 | 16 (30%) | 0 | 32 (23%); 6 (4%) | 4 (8%); 0 |
| Four antigens | 68 (91%) | 0 | 30 (56%) | 2 (5%) | 51 (37%); 19 (14%) | 12 (24%); 1 (2%) |
| Three antigens | 72 (96%) | 1 (2%) | 41 (76%) | 2 (5%) | 78 (56%); 46 (33%) | 14 (29%); 1 (2%) |
| Two antigens | 75 (100%) | 3 (6%) | 48 (89%) | 4 (10%) | 107 (77%); 78 (56%) | 22 (45%); 8 (16%) |
| One antigen | 75 (100%) | 9 (18%) | 52 (96%) | 9 (23%) | 133 (96%); 117 (84%) | 41 (84%); 22 (45%) |
| None | 0 | 40 (82%) | 2 (4%) | 31 (78%) | 6 (4%); 22 (16%) | 8 (16%); 27 (55%) |
| Plasma | ||||||
| Five antigens | 21 (28%) | 2 (4%) | 10 (19%) | 2 (5%) | 33 (24%) | 4 (8%) |
| Four antigens | 42 (56%) | 2 (4%) | 16 (30%) | 4 (10%) | 47 (34%) | 10 (20%) |
| Three antigens | 65 (87%) | 2 (4%) | 26 (48%) | 6 (15%) | 65 (47%) | 14 (29%) |
| Two antigens | 70 (93%) | 5 (10%) | 38 (70%) | 8 (20%) | 89 (64%) | 22 (45%) |
| One antigen | 74 (99%) | 14 (29%) | 52 (96%) | 19 (48%) | 122 (88%) | 31 (63%) |
| None | 1 (1%) | 35 (71%) | 1 (2%) | 21 (53%) | 17 (12%) | 18 (37%) |
Data are n (%). ALS responses on day 7 or day 19 are shown for children aged 12–59 months; for infants aged 6–11 months, mucosal IgA data are presented as faecal secretory IgA responses followed by ALS responses (below). A response was defined as at least a two-times increase in antibody levels between preimmunisation and days 7 or 19. ALS=antibodies in lymphocyte secretions. ETVAX=enterotoxigenic Escherichia coli vaccine.