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 IsolatesEuropeanNorth 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 22 39 14 53   9 6 103 19 16 35     5  4 443 60 503   1 2 15 156 14 170   6 6 56 77 13 90   8 8 87 163 2 165   5   68 15 2 17        

S

1 327 17 344   2 4 32 172 8 180   4 9 43 35 21 56   10 3 94 21 4 25        5 150 7 157   7 10 76 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

45 Mortality 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