Application of MJ PRRS Vaccine for PRRS Control and Elimination AASV 2010, Omaha, NE Neil DeBuse, DVM

Objectives  Provide brief technical background  Grouping  Vaccine production process  Important areas for monitoring (veterinarian involvement)  Provide overview of vaccine as we have applied it in the field  Quarterly / Sow Unit protocol  Pre-farrow / Sow Unit protocol  Provide a look at our initial results  Sow unit  Results from start to current  Nursery situations with post-exposure vaccination

Previous information  BK Kim, PhD, Microbiologist  Leman Conference Making sense of PRRS virus sequences and a new view for PRRS inactivated vaccine – MJ PRRS tm : old problem-new approach 

Technical Background  Strain Selection  Methodology is patent pending  Grouping; D, S, E x 8 subgroups PRRSV Isolates European North American Strains Group DGroup S E-1 E-2 E-3 E-4 E-5 E-6 E-7 D S E-8

Vaccine Production Process

PRRS Isolate “demographics” Occurrence of Viruses x Region Top 10 Most Common Group Sub- Group IA/MN Other States Entire US IA/MN Other States Entire US D S E ALL (1-8) TOTAL SE Minnesota Area 90% of vaccine used is D145, S15 within our veterinary group / 10% with D6

Background  MJ PRRS Vaccine became available in 2007  A group of 4 veterinary clinics collaborated to use vaccine (common strains) in 4-county area  Dr. Tom Lang  Dr. Mark Engesser  Dr. Mike Strobel  Dr. Neil DeBuse  Collaboration allowed us to use single product, evaluate in various situations and discuss clinical response  Good learning curve  Faster “test”

Elimination of Sow Unit level Without introducing live virus….can we take these steps? Step 1: Ability to produce PRRS negative weaned pigs for > 12 months Step 2: No new clinical signs - No abortions - No PRRS circulation within the sow unit Step 3: Extend to 2 years Step 4: Introduction of PRRS naïve (negative) gilts (a step of herd closure or more knowledge on immunization of naïve gilts may be needed). Overall Strategy

Sow Unit Protocols  Pre-farrow  Extremely effective colostrum-based protection  Vaccination timing  8-weeks pre-farrow  aim at protection against late-gest viremia  weeks pre-farrow  Maximum colostrum; protection into Nursery  Quarterly  Focus for stabilization of sow unit / stop virus circulation  Focus on all sows having equal protection/status  Continue to prevent “re-breaks” with area strains

Case 1: 4 sow units Herd Status at Start  All herds positive, acclimating gilts with one of the two commercial MLV vaccines  Quarterly “blitz” of all sows  Continued PRRS symptoms  Vaccinating 100% of weaned pigs 2x in Nursery (BI ATP)

Case 1: Intervention and Plan Individual Herd Actions  Stop all “ blitz” with live virus  Use conventional mlv for priming gilts  Vaccination whole herd with MJ PRRS TM  Continued Quarterly vaccination  5 th quarter  MJ PRRS in gilts  1 st dose - MJ PRRS – 6-8 weeks after priming  2 nd dose 6-8 weeks later  NOTE: All herds had multiple PRRS strain exposure history (D1, D4, D5)

Case 1: Results Herd 1, 2, 3  PRRS negative weaned pigs within 8 weeks  Weaning consistently negative pigs, throughout 2009  A single nursery site with PRRS positive results in offsite/downstream (not related to “leaking” virus)  100% Success Herd 4  PRRS negative weaned pigs quickly (2 months), but on-site nursery has had sporadic POSITIVES  Partial depopulated nursery rooms  Strict bio-security back from nursery to sow unit  Virus still present in the Oct-2009  In Nov-09: converted from Quarterly to Pre-Farrowing protocol  Results: Reduced N Mortality & % PCR +

Case 1: Next steps  Monitoring PRRS serology monthly  Herds 1-3  Continue Quarterly MJ-PRRS use  If 100% weekly PRRS negative pigs through 2010, enter PRRS naive gilts in 2011  Monitor serologically  If ELISA change or weaned pig change, re-implement or review action plan  Herd 4  Continue on Pre-Farrow protocol  Eliminate PRRSV at Nursery

Case 2: Active Sow Unit Break Nov/Dec 2008: 1. Sow unit with 2,500 sows; abortions at 12-18/week for 6 weeks 2. Vaccine became available and 1x herd administration 3. Abortions 14 days post-vaccine 4. Negative weaned pigs at 5 weeks Result:  Dramatic results in stopping clinical signs in sows, making negative weaned pigs  Achieved 20 weeks of consistent negative pigs (PCR)  Monitoring smallest weaned pigs -10/week  Stopped 6 mo.

Our Assessment Clinically 1. Rapid affect on passive immunity 2. Stop late gestation viremia  reduce in utero infection 3. Suppression of viremia in herd (population) vs. our previous tactics (lvi) --- We have not performance serum exposure (lvi) in a sow unit since this case. We have adapted to an 8-week prefarrow or weeks prefarrow depending on nursery flow

Summary – Breeding Herd Application  Successfully taken 18 herds through 2009  Reduced PRRS virus leakage  Reduced Sporadic Abortion storms  We will have 8-9 of these herds (non-endemic area) go towards elimination in  We will have 9-10 of these herds remain on pre-farrow protocol during  Developed a better approach to get to PCR negative pigs rapidly  MJ-PRRS vaccine 5-6 weeks vs.  Live virus intervention ~ week average (range10-22 wks)

Weaned Pig / Nursery  We have used in limited basis for approx 45,000 pigs  Efforts directed at controlling symptoms and viremia following an outbreak in large Continuous Flow Nursery  Vaccination post-exposure (approx 1 week)  Focus on monitoring room by room  Vaccinate 1 week post exposure (natural infection)

Nursery History Logic  PRRS negative system  Purchased weaned pigs  Negative nursery flow  New outbreak  Need for plan to control PRRS  Risk to other finishing sites  Make Nursery negative again Sow unit 1Sow Unit 2 Large CF Nursery

Nursery Application Actions  Vaccinated outgoing pigs  MJ PRRS post exposure  Reduce finishing impact  8 groups  N Mort: 16.3%  Vaccinated new groups  1 week post “clinical” symptoms  Room by room  9 groups  N Mort: 6.4% Sow unit 1Sow Unit 2 Large CF Nursery *

Nursery results PRRS + & exit to F PRRS + & 1 week post clinical

Elimination of Sow Unit level Without introducing live virus….can we take these steps? Step 1: Ability to produce PRRS negative weaned pigs for > 12 months Step 2: No new clinical signs - No abortions - No PRRS circulation within the sow unit Step 3: Extend to 2 years Step 4: Introduction of PRRS naïve (negative) gilts (a step of herd closure or more knowledge on immunization of naïve gilts may be needed). Overall Strategy

Summary  We have a new tool which has been very helpful  Breeding herd  Nursery  Continue to collect and share information within group  Thank you