Table 5.
Effect of maternal inactivated influenza vaccine on birth outcomes
|
Intervention |
Control |
Risk ratio (95% CI) | p value | |||||
|---|---|---|---|---|---|---|---|---|
| Cases | Infants, n | Incidence, per 100 infants | Cases | Infants, n | Incidence, per 100 infants | |||
| Low birthweight | ||||||||
| Nepal | 318 | 1386 | 22·9 | 370 | 1367 | 27·1 | 0·85 (0·74–0·96) | 0·01 |
| Mali | 191 | 2061 | 9·3 | 165 | 2038 | 8·1 | 1·14 (0·94–1·40) | 0·18 |
| South Africa | 133 | 1024 | 13·0 | 122 | 1021 | 11·9 | 1·09 (0·86–1·37) | 0·48 |
| Pooled | 642 | 4471 | 14·4 | 657 | 4426 | 14·8 | 0·96 (0·87–1·06) | 0·39 |
| Stillbirth | ||||||||
| Nepal | 33 | 1858 | 1·8 | 31 | 1861 | 1·7 | 1·07 (0·66–1·73) | 0·80 |
| Mali | 24 | 2088 | 1·1 | 30 | 2071 | 1·4 | 0·79 (0·46–1·35) | 0·40 |
| South Africa | 15 | 1044 | 1·4 | 9 | 1037 | 0·9 | 1·66 (0·73–3·77) | 0·23 |
| Pooled | 72 | 4985 | 1·4 | 70 | 4965 | 1·4 | 1·02 (0·74–1·42) | 0·88 |
| Preterm birth | ||||||||
| Nepal | 234 | 1767 | 13·2 | 255 | 1760 | 14·5 | 0·91 (0·78–1·08) | 0·28 |
| Mali | 201 | 2064 | 9·7 | 204 | 2041 | 10·0 | 0·97 (0·81–1·17) | 0·78 |
| South Africa | 108 | 1026 | 10·5 | 96 | 1023 | 9·4 | 1·12 (0·86–1·46) | 0·39 |
| Pooled | 543 | 4857 | 11·2 | 555 | 4824 | 11·5 | 0·97 (0·87–1·08) | 0·60 |
| Small for gestational age | ||||||||
| Nepal | 553 | 1307 | 42·3 | 574 | 1301 | 44·1 | 0·96 (0·88–1·05) | 0·35 |
| Mali | 435 | 1685 | 25·8 | 420 | 1640 | 25·8 | 1·01 (0·90–1·13) | 0·89 |
| South Africa | 117 | 715 | 16·4 | 102 | 740 | 13·8 | 1·19 (0·93–1·52) | 0·17 |
| Pooled | 1105 | 3707 | 29·8 | 1096 | 3681 | 29·8 | 0·99 (0·93–1·06) | 0·80 |