Evaluation of PRRSv Challenge Dose in Vaccinated Pigs - Dr. Reid Philips, Veterinarian, Swine Health Division, Boehringer Ingelheim, from the 2016 Boehringer Ingelheim Vetmedica, Inc. Swine Health Seminar, February 26, New Orleans, LA, USA. More presentations at http://www.swinecast.com/2016-boehringer-ingelheim-aasv

1. Comparative Efficacy Evaluation of Two
Modified-Live PRRS Vaccines
AASV Annual Meeting
Industrial Partners
February 28th, 2016

2. Study Objective
• Directly compare the efficacy of Ingelvac PRRS®
MLV and Prime Pac™ PRRS+ against a
heterologous PRRSV challenge in a standard
respiratory challenge in growing pigs

3. Primary Objective:
Question?
• Are there detectable – measurable efficacy
differences between Ingelvac PRRS® MLV and
Prime Pac™ PRRS+ following a relevant
heterologous PRRSV challenge?

4. Study Design
• Randomized and blinded vaccination-challenge
study
• Pigs used for the study were 3 wks of age and
PRRSV naïve – confirmed PCR negative
• Day 28 Challenge (4 wks post-vaccination) w/
PRRSV SDSU-73
• 89.7% homologous to Ingelvac PRRS® MLV
• 91.3% homologous to Prime Pac™ PRRS
• Day 42 Post-challenge necropsy (2 wks post-
challenge)
• Lung lesion evaluation for percent pneumonia associated
w/ PRRS exposure

5. Study Design
Group
No. of
Ingelvac
PRRS®
MLV
Vaccinat
ed Pigs
(2ml IM)
No. of
Prime
PacTM
PRRS
Vaccinate
d Pigs
(1ml IM)
No. of
Challenge
Control Pigs
PRRSV SDSU-
73
Challenge
Dosage
(Log10
TCID50/ml)
Necropsy
Subset of
Groups
1,2 & 3
(lung lesion)
Necropsy
Remaining
Pigs
Day 0 Day 0 Day 0 Day 28 Day 42 Day 70
1 20 - - 4.1 10 10
2 - 20 - 4.1 10 10
3 - - 20 4.1 10 10
4 10 - - None 10

6. Study Design
 Parameters measured – Comparative Efficacy Objective
Parameter Day
% Lung Lesions 42
ADWG 28-70 (post-challenge period)
Viremia 28-70 (post-challenge period)
Pyrexia/Temperature 28-42 (post-challenge period)

7. Results – Lung Lesions
• Both vaccinated treatment
groups demonstrated a
large and similar reduction
in lung lesion scores
compared to the non-
vaccinated challenged
treatment group.
• Greater than 85% reduction
• The Ingelvac PRRS® MLV
vaccinated pigs median lung
score was 0.5% vs. 1.3% for
Prime Pac™ PRRS+ group.
Group Treatment
Median
Percent
Lung Score
1
Ingelvac PRRS®
MLV
0.5
2 Prime Pac™ PRRS+ 1.3
3
Challenge Control
(non-vaccinated)
28.6

8. Results – Viremia
 Decline in post-challenge viremia begins earlier in Ingelvac PRRS® MLV
vaccinates. From day 42-63 of the study, Ingelvac PRRS® MLV vaccinates
demonstrate less percent PCR positive pigs than Prime PacTM PRRS and
challenge control pigs.
 Prime PacTM PRRS vaccinated pigs viremia pattern following challenge is similar
to challenge control pigs.
Figure 1. Percentage of viremic pigs per treatment group following PRRSV SDSU-73 challenge
0%
20%
40%
60%
80%
100%
120%
28 31 33 35 38 42 49 56 63 70
%PCRPositive
Days
Ingelvac
PRRS® MLV
Prime Pac
PRRS
Challenge
Control (non-
vaccinated)
Ingelvac
PRRS® MLV
(no Challenge)
TM

9. Results – Pyrexia/Fever
 Ingelvac PRRS® MLV vaccinated pigs maintained lower average
temperatures throughout the challenge phase of the study when compared
to challenge controls
Figure 2. Average daily temperature by treatment group
39.2
39.4
39.6
39.8
40.0
40.2
40.4
40.6
40.8
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
Degrees(C°)
Days
Ingelvac
PRRS® MLV
Prime Pac
PRRS
Challenge
Control (non-
vaccinated)
Ingelvac
PRRS® MLV
(no challenge)
TM

10. Results – Pyrexia/Fever
 Ingelvac PRRS® MLV vaccinated pigs also demonstrated lower average
temperatures compared to Prime Pac™ PRRS+ vaccinated pigs during the first
week post-challenge
 During the first week post-challenge, average temperatures in the Prime Pac™
PRRS+ vaccinated pigs were similar to the challenge controls
Figure 2. Average daily temperature by treatment group
39.2
39.4
39.6
39.8
40.0
40.2
40.4
40.6
40.8
27282930313233343536373839404142
Degrees(C°)
Days
Ingelvac
PRRS® MLV
Prime Pac
PRRS
Challenge
Control (non-
vaccinated)
Ingelvac
PRRS® MLV
(no challenge)
TM

11. Results – Average Daily Weight Gain (ADWG)
• Ingelvac PRRS® MLV vaccinated group demonstrated a 17%
higher ADWG compared to both Prime Pac™ PRRS+ & non-
vaccinated challenge control groups
• ADWG for Prime Pac™ PRRS+ & challenge control groups were similar
• Vaccinated non-challenged group demonstrated best ADWG,
indicating the virulent PRRSV challenge has biologic impact
as measured by ADWG
Group Treatment Group ADWG (lbs)
1 Ingelvac PRRS® MLV 1.41
2 Prime Pac™ PRRS 1.17
3
Challenge Control
(non-vaccinated)
1.18
4
Vaccinated Control
(non-challenged)
1.67

12. Conclusions
• Both Ingelvac PRRS® MLV and Prime Pac™
PRRS+ vaccines demonstrated a large and similar
reduction in PRRSV associated lung lesions
compared to non-vaccinated controls
• Reduction in post-challenge viremia occurred
earlier in Ingelvac PRRS® MLV vaccinated group
compared to Prime Pac™ PRRS+ vaccinated
group
- Pattern of viremia reduction in the Prime Pac™ PRRS+
vaccinated group was similar to non-vaccinated controls

13. Conclusions
• Ingelvac PRRS® MLV vaccinated group maintained lower average
temperatures throughout the challenge phase of the study
compared to Prime Pac™ PRRS+ and challenge control groups
• Reducing fever following challenge/infection is important to mitigate
consequences of infection – helping pigs return to normal feed & water intake
• Ingelvac PRRS® vaccinated group had 17% higher ADWG
compared to both Prime Pac™ PRRS+ and challenge control
groups
- Mitigating the negative biologic impact PRRSV infection has on ADWG can
have significant economic benefit
• In this study, the slower mitigation of viremia & temperature
following challenge in the Prime Pac™ PRRS+ group may have
had a negative impact on overall ADWG
• This study is another example demonstrating the ability of
modified-live PRRS vaccines to protect against a relevant PRRSV
challenge