Distinct immune responses and virus shedding in pigs following aerosol, intra-nasal and contact infection with pandemic swine influenza A virus, A(H1N1)09

Table 1 Median parameters describing influenza viral kinetics for the different challenge groups for virus titre determined by plaque assay

Parameter	Unit	IN high	IN low	AERO high	AERO low	Cont.	p value for dose groups testing*			p value for route groups testing*
Parameter	Unit	N = 3	N = 2^a	N = 3	N = 4	N = 6	Cont. vs. high	Cont. vs. low	Low vs. high	Cont. vs. AERO	Cont. vs. IN	AERO vs. IN
V₀	log₁₀ PFU/mL	0.49 [0.48; 0.53]	0.41 [0.34; 0.47]	0.16 [0.15; 0.22]	0.21 [0.07; 0.33]	−0.02 [−0.05; 0.01]	0.024	0.024	0.711	0.038	0.009	0.009
s₁	log₁₀ PFU/d	3.34 [2.52; 3.52]	0.45 [0.34; 0.56]	1.05 [0.89; 1.18]	0.63 [0.50; 0.77]	0.63 [0.51; 0.69]	0.012	0.755	0.012	0.22	0.22	0.22
Tmax	d	1.42 [1.28; 2.00]	5.62 [5.31; 5.93]	3.16 [3.01; 3.25]	5.12 [4.62; 5.52]	5.60 [4.70; 5.72]	0.006	0.589	0.012	0.13	0.13	0.43
s₂	log₁₀ PFU/mL/d	−0.81 [−0.99; −0.73]	−1.41 [−1.92; −0.90]	−0.96 [−1.07; −0.83]	−1.21 [-1.41; −0.92]	−0.68 [−0.73; −0.63]	0.11	0.15	0.33	0.048	0.261	0.837
Predicted peak	log₁₀ PFU/mL	4.97 [4.84; 5.09]	3.09 [2.25; 3.93]	3.18 [2.95; 3.72]	3.48 [2.49; 4.40]	3.45 [2.43; 3.96]	0.34	0.98	0.34	0.82	0.47	0.47
T_start	dpi	0.16 [0.15; 0.21]	1.95 [1.31;2.58]	0.80 [0.73; 0.89]	1.33 [0.88; 1.87]	1.69 [1.42; 1.96]	0.018	0.579	0.054	0.32	0.32	0.66
T_end	dpi	6.56 [6.27; 6.65]	6.92 [6.48; 7.36]	5.96 [5.56; 5.99]	7.24 [7.00; 7.39]	9.30 [9.11; 9.51]	0.012	0.012	0.024	0.012	0.012	0.831
Predicted dura tion of shedding period	d	6.40 [6.06; 6.50]	4.97 [3.90; 6.04]	5.17 [4.67; 5.26]	5.74 [4.86; 6.60]	7.52 [6.57; 8.10]	0.072	0.096	0.839	0.03	0.16	0.70

[Q1–Q3]: represents the interval between the first and third quartile; N: number of pigs; Median computed from the individual parameters.
^a2 pigs do not have a virus-positive sample on any occasion after the challenge.
* p value computed from pairwise permtuational t test using 1000 permutation and with p value adjusted for multiple testing using Benjamini & Hochberg method. Cont. is for contact.

ISSN: 1297-9716