Table 1.

Peripheral CTL-mediated antiviral protection is short-lived in the absence of antigen

Challenge infection	Immunization*	Virus titer/organ (log10 ± SEM) in time of challenge infection after immunization		No. of surviving mice
		Day 10	Day 60	Day 10	Day 60
LCMV i.f.	3  × 106 GP2.9	2.0  ± 0.1	2.1  ± 0.3
	1  × 105 GP2.9	2.1  ± 0.2	2.5  ± 0.1
	3  × 106 MC57	3.8  ± 0.2	3.7  ± 0.1
vacc-GP i.p.	3  × 106 GP2.9	1.1  ± 0.1	5.9  ± 0.3
	1  × 105 GP2.9	4.0  ± 0.2	5.2  ± 0.1
	3  × 106 MC57	6.1  ± 0.1	6.0  ± 0.1
LCMV i.c.	3  × 106 GP2.9			6/6	2/6
	3  × 106 MC57			0/6	0/6

^*Mice of the same groups as in Fig. 3 were challenged into the footpad (i.f.) with LCMV WE (30 pfu), and 7 days later virus titers were determined in the footpad (LCMV WE i.f.). Alternatively, mice were challenged i.p. with recombinant vaccinia virus expressing LCMV-GP, and virus titers were assessed 5 days later in ovaries (vacc-GP i.p.). Alternatively, mice primed with a high cell dose (6 per group) were challenged i.c. with LCMV WE (30 pfu), and survival was monitored (LCMV WE i.c.).