Evaluation of the efficacy of one dose of autogenous MJPRRS vaccine in nursery pigs

1. Evaluation of the efficacy of one dose of autogenous MJPRRS vaccine in nursery pigs Dr. Mark Wagner, DVM Fairmont Veterinary Clinic Fairmont, MN

2. Purpose of study • Gain a better understanding of the role and efficacy of using the autogenous MJPRRS vaccine in controlling or managing PRRS virus

3. Trial data to be presented • Trial #1 • Vaccination of PRRS naïve pigs at 21 days of age and challenge with field virus at 32 days post vaccination • Trial #2 • Similar repeat of trial #1, pigs challenged at 28 days post vaccination • Trial #3 • Vaccination of PRRS viremic pigs at peak viremia

4. Trial design • Challenge material • Virulent field virus with a 1-18-2 RFLP • Group D-4 under MJPRRS virus grouping system • Preparation of virus material • A 21 day old PRRS naïve pig inoculated with the 1-18-2 field virus • Serum collected 5 days post inoculation and frozen • An aliquot of serum inoculated on cell culture and harvested 7 days later, then frozen

5. Trial design • Analysis of challenge material • Sequencing completed to confirm 1-18-2 virus • Quantitative PRRS PCR’s completed along with TCID50’s

6. Trial design • Challenge dose • Trial #1 • 0.5ml IM plus 0.5ml IN (serum material = 100 viruses) (culture material = 1,000 viruses) • Trial #2 • 0.5ml IM plus 0.5ml IN (culture material = 1,000 viruses) • Trial #3 • 0.05ml IM plus 0.5ml IN (serum material = 55 viruses)

7. Trial design • Vaccination protocol • Treatment group • MJPRRS • 2ml dose that included 10% extra adjuvant (final 20%) • Mycoplasma • 2ml dose • Control groups • Mycoplasma • 2ml dose

8. Trial design • Data collection included • Body temperature • Virus replication based on PRRS Q-PCR’s • Mortality • Average daily gain weight

9. PRRS virus replication data: Data compiled for Trial #1, Trial #2, and Trial #3

10. Summary PRRS virus replication in MJPRRS vaccinated compared to non-vaccinated 21 day old PRRS naïve pigs when challenged to a field virus at 53 and 49 days old (Trial #1 & #2 data) * ORF6 Copies per ml by Quantitative PCR #Infective Virus Particles calculated per ml based on Q-PCR

11. Summary of PRRS virus replication in 26 day old PRRS viremic pigs vaccinated with MJPRRS vaccine at the peak of viremia compared to non-vaccinated controls (Trial #3 data) * ORF6 Copies per ml by Quantitative PCR # Infective Virus Particles calculated per ml based on Q-PCR

12. Average daily gain data: Data compiled for Trial #1 and Trial #2

13. Summary of Average Daily Gain (ADG) performance in MJPRRS vaccinated compared to non-vaccinated 21 day old PRRS naïve pigs when challenged to a field strain of PRRS at 53 days of age (Trial #1 data) * All pigs challenged with PRRSvat 32 days post arrival (53 days of age) # ADG affected by mortality; Vaccinated group, 1 of 22 dead Non-vaccinated group, 4 of 22 dead

14. Summary of Average Daily Gain (ADG) performance in MJPRRS vaccinated compared to non-vaccinated 21 day old PRRS naïve pigs when challenged to a field strain of PRRS at 49 days of age (Trial #2 data) * All pigs challenged with PRRSvat 28 days post arrival (49 days of age)

15. Mortality data: Data compiled for Trial #1, Trial #2, and Trial #3

16. Summary of Mortality in MJPRRS vaccinated compared to non-vaccinated 21 day old pigs when challenged to a field strain of PRRS at 53 or 49 days of age (Trial #1 and #2 data) Overall mortality for non-vaccinated groups, 18.2% Overall mortality for vaccinated groups, 4.5%

17. Summary of Mortality in 26 day old PRRS viremic pigs vaccinated with MJPRRS vaccine at peak viremia compared to non-vaccinated controls (Trial #3 data) * 15 days post challenge

18. Summary (I) • Virus Replication • For trial #1, a statistical reduction in virus replication shown between the MJPRRS vaccinates compared to the non-vaccinates at days 5 and 11 post challenge (p value = 0.04 and 0.0098, respectively) • For trial #2, no statistical difference noted • For trial #3, a statistical reduction in virus replication during vaccination at peak viremia at day 7 and 10 post vaccination (p value = 0.048 and 0.002, respectively)

19. Summary (II) • Average Daily Gain (ADG) • For trial #1, no statistical difference noted Numerically: Vaccinates, Day 1-23 post challenge, 0.76 Non-Vaccinates, Day 1-23 post challenge, 0.89  High mortality in non-vaccinates likely affected ADG differences in calculation • For trial #2, A statistical difference (p value = 0.026) between MJPRRS vaccinated group vs. controls during Day 1-24 Numerically: Vaccinates, Day 1-24 post challenge, 0.74 Non-Vaccinates, Day 1-24 post challenge, 0.52

20. Summary (III) • Mortality • For trial #1 • Vaccinates = 1 of 22 (4.5%) • Non Vaccinates = 4 of 22 (18%) • For trial #2 • No mortality in either group • For trial #3 • Vaccinates = 2 of 12 (16%) • Non Vaccinates = 3 of 12 (25%)

21. Conclusions • Data demonstrated that PRRS naïve or viremic pigs were able to respond to one dose of autogenous MJPRRS vaccine with extra adjuvant. • A reduction on virus replication was statistically demonstrated (2 of 3 trials). • A numerical improvement in ADG was demonstrated (2 of 2 trials). A statistical difference noted also (1 of 2 trials). • A numerical improvement in Mortality was demonstrated (2 of 3 trials).

22. Thank you