Table 6.

Effect of challenge route on perceived vaccine efficacy

	Infected/total mice
Groups	pCSP(-A)a)	pcDNA a)
gene gun vaccination, SQ challenge	0/10	9/10
gene gun vaccination, IV challenge	15/15	12/12
IM vaccination, SQ challenge	5/10	ND
IM vaccination, IV challenge	15/15	13/13

a) BALB/c mice were immunized by gene gun or intramuscular injection with plasmid encoding CSP or empty vector. 10-15 mice/group were challenged through the subcutaneous (with 5,000 SPZ) or intravenous (with 300 SPZ) route using the same batch of isolated P. berghei SPZ. Shown are the numbers of infected/total number of mice per group. The experiment was independently repeated using different, but overlapping challenge doses.