Bovine Respiratory Syncytial Virus (BRSV) Pneumonia in Beef Calf Herds Despite Vaccination

Table 1a Virological and serological findings in vaccinated calves during acute outbreak of respiratory disease in herd A (a) and herd B (b). Nasal swabs were taken at the acute phase (20/26 Jan) and paired serum samples were taken at the acute phase and one month later (18/19 Feb). The nasal swabs were analysed for the presence of bovine respiratory syncytial virus (BRSV), bovine corona virus (BCV) and parainfluenza-3 virus (PI-3) antigen (Ag) by ELISA. Serum samples were analysed for the presence of antibodies against BRSV (IgM, IgA, IgG₁, IgG₂ isotypes) and neutralising antibodies (SNT), BCV (Ab) and PI-3 (Ab). Significant change in antibody titers were defined as either sero-conversion (from 0 to any titer) or at least four-fold rises. Dead: The calf died between the two sampling dates. NA: Not applicable. * Insufficient amount of sample for testing.

	BRSV Ag	BRSV-IgM		BRSV-IgA		BRSV-IgG1			BRSV-IgG2			BRSV-SNT
Calf #	20 Jan	20 Jan	19 Feb	20 Jan	19 Feb	20 Jan	19 Feb	Rise	20 Jan	19 Feb	Rise	20 Jan	19 Feb	Rise
332	+	0	Dead	0	Dead	0	Dead	NA	0	Dead	NA	64	Dead	NA
338R	0	0	0	0	40	80	2560	YES	0	2560	YES	16	2048	YES
325	+	0	*	0	0	40	160	YES	0	*	NA	16	1024	YES
340	0	0	0	0	20	160	1280	YES	40	2560	YES	64	256	YES
244N	0	0	Dead	0	Dead	40	Dead	NA	0	Dead	NA	8	Dead	NA
416	0	0	0	0	20	20	2560	YES	0	640	YES	4	128	YES
421H	0	0	0	0	160	20	160	YES	0	10240	YES	16	2048	YES
426H	0	0	0	0	0	40	160	YES	40	160	YES	256	32	NO
407H	0	0	0	0	0	0	320	YES	0	1280	YES	2	1024	YES
436H	0	0	0	0	0	40	5120	YES	0	40	YES	8	2048	YES
	BCV Ag	BCV Ab			PI-3 Ag	PI-3 Ab
Calf #	20 jan	20 Jan	19 Feb	Rise	20 Jan	20 Jan	19 Feb	Rise
332	0	800	Dead	NA	0	0	Dead	NA
338R	0	12800	12800	NO	0	0	0	NO
325	0	1600	3200	NO	0	8	8	NO
340	0	3200	1600	NO	0	8	8	NO
244N	0	3200	Dead	NA	0	8	Dead	NA
416	0	1600	1600	NO	0	0	0	NO
421H	0	3200	3200	NO	0	0	0	NO
426H	0	800	6400	YES	0	0	0	NO
407H	0	1600	1600	NO	0	0	0	NO
436H	0	3200	6400	NO	0	0	0	NO

ISSN: 1751-0147