Table 3. Vaccine efficacy against P. falciparum malaria, intention-to-treat cohort.

	FMP2.1/AS02A				Control				Vaccine Efficacy
	n	Events	PYAR	Rate†	n	Events	PYAR	Rate†	% (95% CI)	p-value
Months 0–24
First or only malariaepisode	199	142	196.4	0.72	201	141	178.7	0.79	7.6% (−16.7, 26.8%)*	0.51
All malaria episodes	199	299	388.5	0.77	201	325	380.5	0.85	9.9% (−5.4, 23.0%)‡	0.19
Months 0–8
First malaria episode	199	95	94.1	1.01	201	106	87.3	1.21	17.6% (−8.7, 37.5%)*	0.17
All malaria episodes	199	121	127.2	0.95	201	150	125.8	1.19	20.2% (−1.4, 37.2%)‡	0.06
Months 9–24
All malaria episodes	186	178	261.3	0.68	191	175	254.7	0.69	ND	ND

PYAR, Person Years At Risk. CI, confidence interval. ND, not done.

^*Efficacy was calculated as 1– hazard ratio obtained using Cox proportional hazards modeling.

^†Rate of malaria episodes per person-year at risk.

^‡Efficacy was calculated as 1– risk ratio obtained using Poisson regression.