Table 2.

Overview of the efficacy data

Parameter	Study day	NCG	PCG	Lipo_DDA:TDB	PLGA_TLR	SWE_TLR	P value
RDS	−6 until 56	0.01 ± 0.01	0.68 ± 0.32b	0.42 ± 0.33ab	0.33 ± 0.35ab	0.26 ± 0.15a	0.011
	−6 until 27	0.00 ± 0.00	0.00 ± 0.00a	0.00 ± 0.00a	0.00 ± 0.00a	0.00 ± 0.01a	0.415
	28 until 56	0.01 ± 0.03	1.47 ± 0.69b	0.90 ± 0.73ab	0.73 ± 0.77ab	0.56 ± 0.33a	0.011
ADG in g/pig/d	0 until 56	691 ± 69	655 ± 109a	610 ± 90a	628 ± 97a	688 ± 49a	0.065
	0 until 28	620 ± 47	592 ± 104a	560 ± 104a	586 ± 106a	581 ± 70a	0.526
	28 until 56	762 ± 98	739 ± 141ab	660 ± 96a	669 ± 127a	795 ± 69b	0.004
Number of animals with macroscopic lung lesions (% positive animals)	56	0/5 (0.00)	11/11 (100.00)	7/12 (58.33)	7/12 (58.33)	7/12 (58.33)	–
Macroscopic lung lesion score	56	0.00 ± 0.00	7.57 ± 5.18b	2.28 ± 3.55a	1.43 ± 2.31a	0.88 ± 1.01a	0.002
Microscopic lung lesion score	56	1.13 ± 0.18	3.73 ± 0.94b	2.11 ± 0.89a	2.22 ± 0.87a	1.78 ± 0.57a	< 0.001
Percentage of lung area occupied by air	56	39.11 ± 6.26	23.38 ± 6.43b	37.57 ± 5.99a	34.82 ± 4.28ab	42.15 ± 7.98a	< 0.001
Number of animals positive for M. hyopneumoniae in BAL fluid (% positive animals)	42	0/5	11/11 (100.00)	9/11 (81.82)	9/12 (75.00)	6/12 (50.00)	–
	56	0/5	8/11 (72.73)	5/12 (41.67)	6/12 (50.00)	4/12 (33.33)	–
Log copies M. hyopneumoniae DNA/mL BAL fluid	42	0.00 ± 0.00	3.82 ± 0.71b	2.50 ± 1.18ab	2.20 ± 1.38a	1.25 ± 1.28a	< 0.001
	56	0.00 ± 0.00	1.74 ± 0.94a	1.24 ± 1.34a	1.76 ± 1.68a	0.63 ± 0.74a	0.082

Pigs were prime-boost vaccinated on D0 and D14 with three different experimental M. hyopneumoniae bacterins (Lipo_DDA:TDB, PLGA_TLR, SWE_TLR), challenge infected on D28–29 and euthanized on D56. For the parameters ADG, macroscopic lung lesion score, microscopic lung lesion score, % air and number of M. hyopneumoniae organisms in BAL fluid, a Kruskal–Wallis ANOVA was performed to determine statistical differences between the groups on each time point. For the parameter RDS, a repeated measurements ANOVA with Scheffé’s post hoc test was performed. The NCG was not included in the statistical analyses. Groups that have no superscript in common are significantly different from each other (P ≤ 0.05). All results are expressed as mean ± SD, unless otherwise stated.

NCG: non-challenge control group (non-vaccinated, non-challenge infected), PCG: PBS-injected control group (non-vaccinated, challenge infected), RDS: respiratory disease score, ADG: average daily gain, BAL: bronchoalveolar lavage.