Table 3.

 Vaccine effectiveness comparisons (vaccinated = at least 10 days prior to disease)

	H1N1+	H1N1−	Point estimate	Vaccine effectiveness (VE) 95% C I
Children 6–119 months
Vaccinated	1	29	P < 0·0001, VE = 95·7%	66·0–99·4%
Not vaccinated	27	34
Total	28	63
Children 6–59 months
Vaccinated	0	13	P = 0·002, VE = 100%	62·8–100%
Not vaccinated	18	22
Total	18	35
Children 60–119 months
Vaccinated	1	16	P = 0·01, VE = 91·7%	21·2–99·8%
Not vaccinated	9	12
Total	10	28
Children 6–35 months
Vaccinated	0	10	P < 0·05, VE = 100%	11·4–100%
Not vaccinated	9	18
Total	9	28
Children 36–119 months
Vaccinated	1	19	P < 0·001, VE = 95·3%	62·2–99·9%
Not vaccinated	18	16
Total	19	35

*Fisher’s exact one‐sided test statistic used as an expected cell size <5 present. Other estimate chi‐square.