. 2012 Apr 19;43(1):30. doi: 10.1186/1297-9716-43-30

Table 1.

Experimental design

	Groups	1^stChallenge* (0 pi)	2^ndChallenge* (84 pi)
Experiment 1 20 pigs	A	strain 3262	Group A + A (n = 4)
	A		Homologous challenge: strain 3262
	14 pigs^†		Group A + B (n = 4)
	14 pigs^†		Heterologous challenge: strain 3267
	C1	Placebo	Group C1 + B (n = 2)
	6 pigs^††	Placebo	naïve controls: strain 3267
Experiment 211 pigs	B	strain 3267	Group B + B (n = 4)
	B		Homologous challenge: strain 3267
	8 pigs		Group B + A (n = 3**)
	8 pigs		Heterologous challenge: strain 3262
	C2	Placebo	Group C₂ + A (n = 3)
	3 pigs	Placebo	naïve controls: strain 3262

* Inoculation was performed intranasally (2 mL; 1 mL/nostril) with a dosis of 5 × 10^5.0 TCID₅₀/mL of the corresponding strain

** One pig died at 17 pi in the first inoculation.

† Six pigs were euthanized; three at 15 pi and three at 35 pi.

†† Four pigs were euthanized: two at 15 pi and two at +35 pi.