Table 2.
Vaccine effectiveness comparisons (vaccinated = at least 14 days prior to disease)
| H1N1+ | H1N1− | Point estimate | Vaccine effectiveness (VE) 95% CI | |
|---|---|---|---|---|
| Children 6–119 months | ||||
| Vaccinated | 0 | 24 | P = 0·0001, VE = 100% | 79·5–100% |
| Not vaccinated | 28 | 39 | ||
| Total | 28 | 63 | ||
| Children 6–59 months | ||||
| Vaccinated | 0 | 10 | P < 0·01, VE = 100% | 44·0–100% |
| Not vaccinated | 18 | 25 | ||
| Total | 18 | 35 | ||
| Children 60–119 months | ||||
| Vaccinated | 0 | 14 | P = 0·004, VE = 100%* | 56·6–100% |
| Not vaccinated | 10 | 14 | ||
| Total | 10 | 28 | ||
| Children 6–35 months | ||||
| Vaccinated | 0 | 8 | P = 0·08* | −25·7–100% |
| Not vaccinated | 9 | 20 | ||
| Total | 9 | 28 | ||
| Children 36–119 months | ||||
| Vaccinated | 0 | 16 | P < 0·001, VE = 100%* | 75·5–100% |
| Not vaccinated | 19 | 19 | ||
| Total | 19 | 35 | ||
*Fisher’s exact one‐sided test statistic used as an expected cell size <5 present. Other estimate chi‐Square.