Vaccine Protection Against Experimental Challenge Infection with a PPV-27a Genotype Virus in Pregnant Gilts

Figures & data

Table 1 List and Composition of the Vaccines Used in This Study

Group/Vaccine	PPV Strain	Other Component	Adjuvant
G1. Parvoruvax	K22 (“Kresse-like”)	Inactivated E. rhusiopathiae	AlOH, thiomersal
G2. Vaccine B	NADL-2	Inactivated E. rhusiopathiae	AlOH, DEAE-dextran, ginseng
G3. Vaccine C	“NADL-like” strain 014	Inactivated E. rhusiopathiae	α-tocoferylacetat; Polysorbate 80, Simethicone
G4. Vaccine D	“NADL-like” strain 014	Inactivated E. rhusiopathiae; L. interrogans serovars	d1-α-tocoferylacetat

Figure 2 Serological response of the gilts over time to vaccination and challenge measured by a commercial blocking ELISA. The dashed line indicates the cut-off of the ELISA.

Table 2 Serum Virus Neutralization Titers of the Gilts After Vaccination and Pre-Challenge Against 100 TCID₅₀ PPV1-HUN Strain

Group	Gilt ID	D38 Log Titer	D86 Log Titer
Parvoruvax	51	1.3	0
	55	0	0
	56	2.35	1.15
	70	1.9	0
	74	1.6	0
	75	1	0
	78	0	0
Vaccine B	46	1.76	1.45
	48	1.15	1.6
	54	1.3	1.15
	81	1.9	1.76
	84	0	0
	87	1.76	1.15
	88	1.3	0
Vaccine C	11	1.15	0
	17	0	0
	58	0	1.15
	63	1	0
	89	1	0
Vaccine D	1	1.3	0
	12	0	1.76
	18	1.15	0
	23	0	0
	34	1.6	0

Table 3 Physiological Parameters of the Litters

Group (# of Sows)	% Sows with PPV Affected Litter (Dead or Mummified)	Average Live Litter Size	Number (%) of Live Foetuses	Number (%) of Dead Foetuses	Number (%) Mummified of Foetuses	Average Live Foetus Weight (g)	Average Live Foetus Length (cm)	% Ingezim PPV ELISA Positive Foetuses
Parvoruvax (7)	0	13.7	96 (100)	0 (0)	0 (0)	600.1	29.4	0
Vaccine B (7)	43	11.4	80 (89)	0 (0)	10 (11)	609.9	29.4	0
Vaccine C (5)	60	11.0	55 (92)	0 (0)	5 (8)	719.8	31.0	0
Vaccine D (5)	80	9.4	47 (64)	0 (0)	26 (36)	555.1	28.8	4
No vaccine control (6)	100	7.6	46 (40)	5 (4)	65 (56)	663.4	30.4	26

Table 4 Viral Genome Copy Load and Virus Isolation Measurements Results

Group (# of Sows)	% of PCR Positive Piglets/Group	% of PCR Positive Piglets per Group and Mean Viral Genome Copy Load in the Organs (Kidney/Lung) Calculated log10 TCID50/mg Organ (Min/Max)			# of Virus Isolation Positive Piglets/Group
		Live	Dead	Mummified
Parvoruvax (7)	3	3% 1.1 (0.7/1.7)	N/A	N/A	0
Vaccine B (7)	17.8	7.5% 1.6 (0.9/3.2)	N/A	100% 1.2 (0.3/2.3)	0
Vaccine C (5)	25	18% 1.9 (0.6/3.0)	N/A	100% 1.8 (1.5/2.2)	0
Vaccine D (5)	60.3	57% 2.4 (1.0/5.9)	N/A	100% 4.7 (1.1/7.6)	13
No vaccine control (6)	90.5	78% 4.0 (1.4/7.0)	100% 6.6 (5.9/7.2)	98% 6.0 (1.5/8.1)	36

Abbreviation: N/A, Not Applicable.

Figure 1 Surface amino acid modifications among different PPV strains. All altered amino acids highlighted on the surface of a capsid trimer (the three inter-linked identical monomers are shown in different colors), but changes only on one chain are annotated. Numbering is indicated according to NADL-2 VP2 positions. (A) K22 vs Kresse. Altered neighbouring surface amino acids highlighted with red and blue. (B) K22 vs 27a. Surface amino acid changes are indicated with red and blue. (C) NADL-2 vs 27a. Surface amino acid changes similar to K22 v. 27a are highlighted with red, other amino acid changes are indicated by blue and green.