TABLE 1.

Zinc levels in a mouse experiment to assess the effect of zinc deprivation and PspA immunization on pneumococcal colonization of the nasal mucosa, severe infection, and death after pneumococcal challenge^a

Group	Zinc in femur				Zinc in plasma
	No. of samples	Mean ± SD (μg/g)	Difference between groups (μg/g)	P	No. of samples	Mean ± SD (mg/liter)	Difference between groups (mg/liter)	P
Zinc adequate	24	60.1 ± 11.1	6.1	0.11	24	0.82 ± 0.3	0.39	<0.0005
Zinc depleted	22	54.0 ± 14.2			13	0.43 ± 0.2
Immunized	23	61.6 ± 13.6	8.7	0.02	18	0.77 ± 0.4	0.18	0.08
Unimmunized	23	52.9 ± 10.9			19	0.59 ± 0.2
Zinc adequate
Immunized	12	62.6 ± 10.9	4.9	0.29	12	0.93 ± 0.3	0.23	0.03
Unimmunized	12	57.7 ± 11.2			12	0.70 ± 0.2
Zinc depleted
Immunized	11	60.4 ± 16.5	12.8	0.04	6	0.46 ± 0.2	0.05	0.72
Unimmunized	11	47.6 ± 7.9			7	0.41 ± 0.2

^aMeans and mean differences are presented; Student's t tests assuming unequal variances were used to estimate the level of significance for the differences between the experimental groups. Thirty-seven mice survived until sacrifice, when blood for analysis of zinc in plasma was collected.