The latest on Porcine Epidemic Diarrhea Virus (PEDV) - Dr. Meggan Bandrick, Zoetis, from the 2016 North American PRRS Symposium, December 3‐4, 2016, Chicago, Illinois, USA.
More presentations at http://www.swinecast.com/2016-north-american-prrs-symposium
Dr. Meggan Bandrick - The latest on Porcine Epidemic Diarrhea Virus (PEDV)
1. 1
Efficacy of Sow PEDV Vaccination
as Evaluated by Piglet Challenge
Meggan Bandrick
Zoetis, VMRD, Global Biologics Research
NA PRRSv Symposium
December, 2016
2. 2
Zoetis is committed to helping producers
& veterinarians fight PEDv
PEDv Conditionally Licensed Vaccine*
Zoetis received a USDA Conditional License
for a Porcine Epidemic Diarrhea Vaccine,
Killed Virus in September, 2014.
Inactivated whole-virus
Contains all relevant immunizing antigens (S-
and M-proteins)
Adjuvanted to help enhance immune response
Requirements for a Conditional License:
*This product license is conditional. Efficacy and potency studies are in progress.
Rapid Disease Onset
Lengthy PEDv shedding
Reasonable Expectation of Efficacy in the target population
Full Safety Evaluation in the target population across geographic sites
Purity testing
Efficacy and potency studies ongoing
3. 3
Introduction and Objective
•Pigs are most susceptible to PEDV immediately following birth.
– Severity of clinical signs decreases with age
– An outbreak on a naïve farm results in 80% -100% mortality
– The disease has become endemic in some farms
•Therefore, to reduce mortality due to PEDV, it is key to protect piglets
immediately following birth.
•The objective of this study was to
evaluate the efficacy of an
experimental Porcine Epidemic
Diarrhea Vaccine when administered
to pregnant sows, with a PEDV
challenge in newborn piglets.
4. 4
STUDY DESIGN
Sows (approximate 6 weeks pre-farrow), sourced from a farm free of PEDV,
were allotted to two treatment groups using a completely randomized design
Sows were assigned to 1 of 10 rooms with each treatment being represented
per room.
Study Design
Treatment
N sows/
litters
Description Dose
Sow
Vaccination
Piglet
Challenge
Study
Conclusion
T01 -
Placebo
10* Adjuvant Placebo
2 mL
IM
5 and 2
weeks pre-
farrow
Virulent
PEDv when
all piglets
per litter
were 1-12
hrs of age
7 days post
piglet
challenge
(dpc)
T02 -
Vaccinated
10
Experimental
PEDV Vaccine
In vivo procedures occurred according to state, national, or international regulations.
5. 5
Endpoints
Sows
Fecal sample: PEDV qPCR
Serum sample: PEDV FFN
• Pre and post vaccination
Piglets
Cause of mortality
• Due to PEDV or not due to PEDv
Gastroenteritis score
Fecal sample: PEDV qPCR
• At necropsy
*Personnel performing animal observations and lab assays were masked to
the assignment of animals to each treatment.
7. 7
RESULTS: Sow Serology
• Sows were negative for PEDV FFN
antibodies pre-treatment; T01 remained
at baseline.
• Vaccination induced an increase in least
squares mean (LSM) PEDV FFN
antibodies in T02 sows.
• T02 sows had significantly greater FFN
responses than T01 sows.
Sow Serology (FFN) on Day 28 (7 days post 2nd vaccination)
Trt N
Back-transformed
least squares mean
SE Range
Lower 95%
confidence
bound
Upper 95%
confidence
bound
T01 –
Placebo
10 10.0 1.1 10 to 10 7.8 12.8
T02 –
Vaccinated
10 52.8 5.7 20 to 80 41.3 67.4
0
10
20
30
40
50
60
70
PEDVFFNAntibodies
T01 - Adjuvant placebo T02 - Experimental PEDV vaccine
P ≤ 0.0001
8. 8
RESULTS: Litter Mortality due to PEDV
• Less piglets from vaccinated litters died due to PEDV compared to piglets
from non-vaccinated litters
Trt
Summary of Least Squares
Means
Contrast vs T01
N % Mortality1 SE2
Mitigated
Fraction
Estimate
95% Bootstrap
P-value
Lower
Limit
Upper
Limit
T01 –
Placebo
10 100 0
T02 –
Vaccinate
10 40.5 15.1 0.70 0.400 1.00 0.0029
9. 9
Litter Mortality due to PEDV
p=0.0029
Of the 10 T01 litters (placebo), no litters/piglets completed the study; the last
pig was removed on 5 dpc.
Of the 10 T02 litters (vaccinate), 7 litters had piglets that completed the study.
10. 10
RESULTS: PEDV Fecal Shedding in Piglets
•Piglets in T02 (vaccinate) shed
significantly less PEDV in their
feces compared to piglets in T01
(placebo).
PEDV (copy number/5uL feces) in Fecal Swabs Collected at Necropsy
Trt N
Back-transformed
least squares mean
SEM Range Lower 95% CI Upper 95% CI
T01 –
Placebo
94 811,136 743,826
2,356.67 to
37,266,666.67
107,102 6,140,000
T02 –
Vaccinate
78 27,124 26,907
0 to
18,000,000
3,276.6 224,476
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
PEDVcopynumber/5uLfeces
(backtransformedleastsquares
meam)
T01 - Adjuvant placebo T02 - Experimental PEDV vaccine
p=0.026
12. 12
CONCLUSIONS
Vaccination resulted in PEDV FFN responses
Vaccination resulted in significantly less mortality and fecal
shedding in litters of vaccinated sows compared to control sows.
Therefore, under the conditions of this study, the experimental
Porcine Epidemic Diarrhea Vaccine is efficacious.
The PEDV vaccine is a tool
to help reduce neonatal
mortality
Editor's Notes
While Current control measures (such as herd closure and feedback) may help reduce the presence of PEDV and result in a return to normal production,
Endemic disease is often accompanied by continued setbacks due to pre-weaning clinical disease and mortality in subsequent farrowings.
Piglet mortality was considered attributable to PEDV unless there was overwhelming evidence to suggest the mortality was not due to PEDV (if the animal completed the study).
The study was valid: no diseases were present that would confound the results of these studies.