TABLE 2.

Parasite burdens in vaccinated BALB/c mice following intradermal infection^a

Group (no. of weeks postinfection)	Parasite burden ± SE in tissue from:
	Earb	Lymph nodec	Spleend	Livere
Naive (12)	1.0 × 103 ± 0.2 × 103	3.3 × 106 ± 1.3 × 106	3.9 × 106 ± 1.1 × 106	3.5 × 104 ± 0.5 × 104
P. acnes immunized (12)	6.9 × 102 ± 1.4 × 102	1.7 × 106 ± 0.6 × 106	8.5 × 105 ± 1.8 × 105	3.0 × 104 ± 1.0 × 104
D-13 vaccinated (12)	1.4 × 102 ± 0.7 × 102	3.1 × 103 ± 0.6 × 103	4.8 × 103 ± 0.6 × 103	1.2 × 103 ± 0.3 × 103
Naive (18)	ND	4.5 × 106 ± 1.5 × 106	1.1 × 107 ± 0.1 × 107	1.3 × 103 ± 0.2 × 103
P. acnes immunized (18)	ND	4.3 × 106 ± 2.0 × 106	0.72 × 107 ± 0.3 × 107	5.4 × 102 ± 2.8 × 102
D-13 vaccinated (18)	ND	6.0 × 102 ± 1.9 × 102	2.3 × 103 ± 0.6 × 103	0.0

^aThe results from vaccination experiments with the intradermal infection model are shown. BALB/c mice were either not immunized (naive) or immunized (as described in Materials and Methods) with either C. parvum or P. acnes alone or together with the D-13 (p80) protective antigen. Mice were infected intradermally 6 weeks after the final immunization with 10⁷ infective late-log-phase L. infantum promastigotes. Parasite burdens (± standard errors) were determined by limiting dilution analyses (3 mice/group) at 12 and 18 weeks postinfection. Reductions in parasite burden were calculated as the number of parasites in naive mice/the number of parasites in the mice vaccinated with the D-13 antigen.

^bParasite burden reductions in the ear were 7-fold at 12 weeks and not determined at 18 weeks. ND, not determined.

^cParasite burden reductions in the lymph node were 1,065- and 7,500-fold at 12 and 18 weeks, respectively.

^dParasite burden reductions in the spleen were 812- and 4,783-fold at 12 and 18 weeks, respectively.

^eParasite burden reductions in the liver were 29-fold at 12 weeks and 1,300-fold (estimated) at 18 weeks.