Table 1.
Overview of the study groups (BE1: Belgium 1; VN1: Vietnam 1; TL1: Thailand 1; BE2: Belgium 2; BE3: Belgium 3).
| Study group | Parent study | Country | Number of mothers | Number of infants | Term/preterm born | Maternal vaccine‡ |
|---|---|---|---|---|---|---|
| BE1 | MATAB 4(14) | Belgium | 57 | 59 | term | Boostrix® |
| VN1 | MATAB 4(13) | Vietnam | 55 | 55 | term | Adacel® |
| TL1 | MATAB 5(9,12) | Thailand | 370 | 370 | term* | Boostrix® |
| BE2 | MATAB 6(15) | Belgium | 112 | 114 | term | Boostrix® |
| BE3 | MATAB 6(15) | Belgium | 82 | 100 | preterm | Boostrix® |
Infants were classified as term or preterm born for analysis on an individual basis, i.e. <37 weeks GAD as preterm and ≥37 weeks GAD as term born. *Not all infants were carried to term in the study groups classified as term; a small proportion of women still had GAD <37 weeks (but ≥36 weeks GAD). ‡Maternal vaccines: Boostrix® (GSK Biologicals, Rixensart, Belgium) composition: 5 Lf of Tetanus Toxoid (TT), 2.5 Lf of Diphtheria Toxoid (DT), 8 µg of inactivated PT, 8 µg of FHA and 2.5 µg of PRN; Adacel® (Sanofi Pasteur, Canada) composition: 5 Lf of TT, 2 Lf of DT, 2.5 µg of inactivated PT, 5 µg of FHA, 3 µg of PRN and 5 µg of fimbriae types 2 and 3.