Application of MJ PRRS Vaccine
for PRRS Control and Elimination
Neil DeBuse, DVM
AASV 2010, Omaha, NE
Objectives
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Provide brief technical background
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Provide overview of vaccine as we have applied it in the field
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Grouping
Vaccine production process
Important areas for monitoring (veterinarian involvement)
Quarterly / Sow Unit protocol
Pre-farrow / Sow Unit protocol
Provide a look at our initial results
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Sow unit  Results from start to current
Nursery situations with post-exposure vaccination
Previous information
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BK Kim, PhD, Microbiologist
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Leman Conference 2008 - Making sense of PRRS virus
sequences and a new view for PRRS inactivated vaccine – MJ
PRRStm: old problem-new approach
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www.mjbio.com
Technical Background
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Strain Selection
Methodology is patent pending
Grouping; D, S, E x 8 subgroups
PRRSV Isolates
North American Strains
Group D
D-1 2 3 4 5 6 7
European
Group S
8
S-1 2 3 4
5 6 7 8
E-1
E-2
E-3
E-4
E-5
E-6
E-7
E-8
Vaccine Production Process
SE Minnesota Area
PRRS Isolate “demographics”
Occurrence of Viruses x Region
SubGroup
Group
D
S
E
TOTAL
Other
States
IA/MN
Top 10 Most Common
Entire
US
Other
States
IA/MN
Entire
US
1
259
131
390
3
1
2
2
39
14
53
9
6
10
3
19
16
35
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
8
15
2
17
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
ALL (1-8)
15
20
35
1930
334
2264
5
6
90% of vaccine used is D145, S15 within our veterinary group / 10% with D6
Background
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MJ PRRS Vaccine became available in 2007
A group of 4 veterinary clinics collaborated to use
vaccine (common strains) in 4-county area
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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
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Good learning curve
Faster “test”
Sow Unit Protocols
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Pre-farrow
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Extremely effective colostrum-based protection
Vaccination timing
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8-weeks pre-farrow  aim at protection against late-gest viremia
8 + 3-weeks pre-farrow  Maximum colostrum; protection into
Nursery
Quarterly
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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 PRRSTM
 Continued Quarterly vaccination 5th quarter
 MJ PRRS in gilts
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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: Results
Herd 1, 2, 3
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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
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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
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Monitoring PRRS serology monthly
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Herds 1-3
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Continue Quarterly MJ-PRRS use
If 100% weekly PRRS negative pigs through 2010, enter PRRS naive gilts in
2011
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Monitor serologically
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If ELISA change or weaned pig change, re-implement or review action
plan
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Herd 4
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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 stopped @ 14 days post-vaccine
4.
Negative weaned pigs at 5 weeks
Result:
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Dramatic results in stopping clinical signs in sows, making
negative weaned pigs
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Achieved 20 weeks of consistent negative pigs (PCR)
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Monitoring smallest weaned pigs -10/week
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Stopped monitoring @ 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 8 + 3 weeks
prefarrow depending on nursery flow
Summary – Breeding Herd Application
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Successfully taken 18 herds through 2009
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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
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MJ-PRRS vaccine 5-6 weeks vs.
Live virus intervention ~ 12-14 week average (range10-22 wks)
Weaned Pig / Nursery
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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
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Vaccination post-exposure (approx 1 week)
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Focus on monitoring room by room
Vaccinate 1 week post exposure (natural infection)
Nursery History
Sow unit 1
Sow Unit 2
Logic
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Large CF Nursery
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PRRS negative system
Purchased weaned pigs
Negative nursery flow
New outbreak
Need for plan to control
PRRS
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Risk to other finishing sites
Make Nursery negative again
Nursery Application
Sow unit 1
Sow Unit 2
Large CF Nursery
*
Actions
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Vaccinated outgoing pigs
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MJ PRRS post exposure
Reduce finishing impact
8 groups  N Mort: 16.3%
Vaccinated new groups
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1 week post “clinical”
symptoms
Room by room
9 groups  N Mort: 6.4%
Nursery results
Mortality Rate
45
40
PRRS + & vaccine @ exit to F
35
PRRS + & vaccine @ 1 week post clinical
30
25
Interrupted incoming flow;
not vaccinated
20
15
10
5
0
Rm 1 Rm 2 Rm 3 Rm 4 Rm 5 Rm 6 Rm 7 Rm 8 Rm 9 Rm Rm 1 Rm 2 Rm 3 Rm 4 Rm 5 Rm 6 Rm 7 Rm 8 Rm 9 Rm Rm 1 Rm 2
10
10
Overall Strategy
Elimination of PRRS @ 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).
Summary
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We have a new tool which has been very helpful
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Breeding herd
Nursery
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Continue to collect and share information within group
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Thank you