Table 1.

Summary of treatments performed in the BALB/c mice

Groups	Route of administration	Treatments a	Mice number
			Total mice	In HI b and CMI c	In challenge d
I	Intramuscular vaccination	100 μl PBS	10	3	7
		100 μg pVAX1	10	3	7
		100 μg pVAX1-MEG-CTXA2/B	10	3	7
II	Intranasal vaccination	200 μl BRD509	10	3	7
		200 μl BRD509/pVAX1	10	3	7
		200 μl BRD509/pVAX1-MEG-CTXA2/B	10	3	7
III	Intraoral vaccination	50 μl BRD509	10	3	7
		50 μl BRD509/pVAX1	10	3	7
		50 μl BRD509/pVAX1-MEG-CTXA2/B	10	3	7

^aThe mice were randomly divided into intramuscular, intranasal and intraoral immunization groups (30 mice per group). For the intramuscular group, the mice were injected 100 μl 1 μg/μl recombinant plasmid or empty plasmid in the quadriceps muscle; For the nasal group, each mouse was given a nasal drip of 50 μl 10⁹ cfu/ml Salmonella bacteria with recombinant plasmid or empty plasmid; The oral group was administrated 200 μl 10⁹ cfu / ml Salmonella bacteria with recombinant plasmid or empty plasmid orally; Each group also had 10 mice which were treated with Salmonella without plasmid or saline as negative control. Mice were vaccinated three times at 2 week intervals.

^bHumoral immunity (HI) was tested by collecting sera from three immunized mice in each group.

^cCellular immunity (CMI) was evaluated by splenocytes from three immunized mice per group 2 weeks after the last immunization.

^dFour weeks after the last immunization, immunized mice were challenged intraperitoneally with 1 × 10³ tachyzoites of T. gondii RH strain.