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Application of MJ PRRS Vaccinefor PRRS Control and Elimination
AASV 2010, Omaha, NENeil 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 2008 - Making sense of PRRS virus sequences and a new view for PRRS inactivated vaccine – MJ PRRStm: old problem-new approach
www.mjbio.com
Technical Background Strain Selection Methodology is patent pending Grouping; D, S, E x 8 subgroups
PRRSV Isolates
EuropeanNorth American Strains
Group D Group S E-1E-2E-3E-4E-5E-6E-7
D-1 2 3 4 5 6 7 8 S-1 2 3 4 5 6 7 8
E-8
Vaccine Production Process
PRRS Isolate “demographics”Occurrence of Viruses x Region Top 10 Most Common
Group Sub-Group IA/MN Other
StatesEntire
US
IA/MN Other States
Entire US
D
1 259 131 390 3 1 2
2 39 14 53 9 6 10
3 19 16 35 5
4 443 60 503 1 2 1
5 156 14 170 6 6 5
6 77 13 90 8 8 8
7 163 2 165 5 6
8 15 2 17
S
1 327 17 344 2 4 3
2 172 8 180 4 9 4
3 35 21 56 10 3 9
4 21 4 25
5 150 7 157 7 10 7
6 32 5 37
7 5 0 5
8 2 0 2 E ALL (1-8) 15 20 35
TOTAL 1930 334 2264
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”
Sow Unit Protocols Pre-farrow
Extremely effective colostrum-based protection Vaccination timing
8-weeks pre-farrow aim at protection against late-gest viremia
8 + 3-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 unitsHerd 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 PlanIndividual Herd Actions Stop all “ blitz” with live virus Use conventional mlv for priming gilts Vaccination whole herd with MJ PRRSTM
Continued Quarterly vaccination 5th quarter
MJ PRRS in gilts 1st dose - MJ PRRS – 6-8 weeks after priming 2nd dose 6-8 weeks later
NOTE: All herds had multiple PRRS strain exposure history (D1, D4, D5)
Case 1: ResultsHerd 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 Nursery @ 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 BreakNov/Dec 2008:1. Sow unit with 2,500 sows; abortions at 12-18/week
for 6 weeks2. Vaccine became available and 1x herd
administration3. Abortions stopped @ 14 days post-vaccine4. Negative weaned pigs at 5 weeksResult: 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 monitoring @ 6 mo.
Our AssessmentClinically1. Rapid affect on passive immunity2. Stop late gestation viremia reduce in utero
infection3. 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 8 +
3 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 2010.
We will have 9-10 of these herds remain on pre-farrow protocol during 2010.
Developed a better approach to get to PCR negative pigs rapidly MJ-PRRS vaccine 5-6 weeks vs. Live virus intervention ~ 12-14 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 1 Sow 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 1 Sow Unit 2
Large CF Nursery *
Nursery results
Rm 1
Rm 2
Rm 3
Rm 4
Rm 5
Rm 6
Rm 7
Rm 8
Rm 9
Rm 10
Rm 1
Rm 2
Rm 3
Rm 4
Rm 5
Rm 6
Rm 7
Rm 8
Rm 9
Rm 10
Rm 1
Rm 2
0
5
10
15
20
25
30
35
40
45Mortality Rate
Interrupted incoming flow; not vaccinated
PRRS + & vaccine @ exit to F
PRRS + & vaccine @ 1 week post clinical
Elimination of PRRS @ Sow Unit levelWithout 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 yearsStep 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
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