Table 4. Allele-specific vaccine efficacy against P. falciparum malaria, intention-to-treat cohort.

	FMP2.1/AS02A				Control				Allele-Specific Efficacy
	n	Events	PYAR†	Rate†	N	Events	PYAR	Rate†	% (95% CI)	p-value
Months 0–24
First or only malariaepisode	199	19	371.0	0.05	201	25	363.7	0.07	35% (−17, 64%)*	0.15
All malaria episodes	199	28	388.5	0.07	201	36	380.5	0.09	24% (−12, 50%)†	0.17
Months 0–8
First or only malariaepisode	199	6	128.5	0.05	201	16	126.7	0.13	64% (8, 86%)*	0.03
All malaria episodes	199	6	127.2	0.05	201	16	125.8	0.13	64% (8, 86%)†	0.03
Months 9–24
First or only malariaepisode	186	13	182.4	0.07	175	9	172.7	0.05	ND	ND
All malaria episodes	186	22	261.3	0.08	175	20	254.7	0.08	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.