1. PRE-HARVEST INTERVENTIONS: The cost benefit ratio of E. coli vaccines

2. MODERATOR Mike Fielding Managing Editor of Technical Content, Meatingplace

3. Efficacy of Pre-harvest Technologies and Interest in Best Practices Guy H. Loneragan, BVSc, PhD Professor of Food Safety & Public Health Texas Tech University, Lubbock, Texas

4. Poll Question Is E. coli O157 predominantly a food-safety challenge in North American? 1.Yes 2.No

5. Outline of Presentation Control of food-borne pathogens in beef production Interest in reducing burden of pathogens in groups of cattle sent to harvest Efficacy of available technologies – Limited discussion based on available time Summary

6. Control of E. coli O157 Informed regulatory oversight and industry implementation of PR/HACCP plans have resulted in greatly improved microbial process control – Impact observed across various metrics 50% decline from baseline years (CDC) 90% reduction in USDA/FSIS ground beef positives

7. Control of E. coli O157 Many slaughter plants are now excelling at microbial process control – Diminishing opportunities for further meaningful improvement in microbial process control during slaughter/fabrication Currently there is very little microbiological control of raw commodity (i.e., cattle) – Can pre-harvest control of pathogens further improve (i.e., impact) process control?

8. Pre-harvest control of E. coli O157 Initial focus on the way we manage & raise cattle – Efforts to date have been largely unsatisfactory E. coli O157 well-adapted to the ruminant gut – Commensal bacterium Worldwide distribution (poll question) – Argentina, UK, Denmark, Australia, Canada, France Incidence greater in Argentina, Scotland, etc., than US – Relationship between cattle and E. coli O157 is robust across various management & rearing systems

9. Pre-harvest control of E. coli O157 Tremendous governmental interest in pre- harvest control of E. coli O157 1994 Public Meeting

10. Pre-harvest control of E. coli O157 Tremendous governmental interest in pre- harvest control of E. coli O157 2003 Public Meeting

11. Pre-harvest control of E. coli O157 Tremendous governmental interest in pre- harvest control of E. coli O157 2008 Public Meeting

12. Pre-harvest control of E. coli O157 Tremendous governmental interest in pre- harvest control of E. coli O157 2010 USDA/FSIS Significant Guidance document

13. Pre-harvest control of E. coli O157 Tremendous governmental interest in pre- harvest control of E. coli O157 2011 Public Meeting

14. Pre-harvest control of E. coli O157 Industry investment and innovation Technologies developed to modify relationship between E. coli O157 & cattle – In-feed (e.g., probiotics, sodium chlorate) – Vaccination – Hide intervention (e.g., bacteriophage)

15. Efficacy of Pre-harvest Technologies Majority of efficacy data about STEC O157 Pre-Harvest Slaughter/Fab In-plant PR/HACCP plant processing aids and interventions

16. Efficacy of Pre-harvest Technologies Majority of efficacy data about STEC O157 Vaccines Direct-fed Microbials (aka probiotics) Na chlorate Phage Slaughter/Fab Pre-Harvest In-plant PR/HACCP plant processing aids and interventions

17. Efficacy of Pre-harvest Technologies Majority of efficacy data about STEC O157 Vaccines Direct-fed Microbials (aka probiotics) Na chlorate Phage Slaughter/Fab Pre-Harvest In-plant PR/HACCP plant processing aids and interventions

18. Direct-Fed Microbials Frequently referred to as probiotics GRAS (approval) for use in cattle – No label claim against food-borne pathogens Thoroughly evaluated against E. coli O157 – Strain specific (NP51) – Dose response High-dose most effective against E. coli O157

19. Direct-Fed Microbials

20. NP51 strain, included in commercially available product, works consistently – When used at the higher dose Reduces prevalence & concentration of E. coli O157 – Brashears et al., 2012 a ab b

21. Type III Secretion System (T3SS) Fully licensed in Canada as Econiche – Label indication: ‘For vaccination of healthy cattle as an aid in the reduction of shedding of Escherichia coli O157’ Not yet licensed in the US – Conditional or full license Peer-reviewed publications published in respected journals support efficacy Vaccine Technologies

22. Source of slide: David Smith, UNL

23. Siderophore receptor and porin proteins – SRP® Technology Developed to control Salmonella in turkey layer flocks – Very effective Approach used to make an SRP-based E. coli O157 vaccine – Epitopix, LLC – Pfizer Animal Health Vaccine Technologies

24. Field Studies of E. coli SRP Vaccine 2006 feedlot study – 20-pen study across 2 feedlots in NE Thomson et al. FPD 6:871-7 2009 – 50% reduction in fecal prevalence over time, P=0.03 – Prevalence at harvest was low Feces:1.4 vs 2.8%VE=50%P=0.18 TRM:1.0 vs 2.3%VE=57%P=0.16 Hides:0.5 vs 1.7%VE=71%P=0.06 – E. coli O157 recovered from 63% fewer animals at harvest (feces, TRM, or hides; P=0.02) 2.5 vs 6.8%

25. Field Studies of E. coli SRP Vaccine 2007 field trial in a commercial feedlot – 3 doses or SRP vaccine or 3 doses of placebo – Vaccine efficacy=85%; 98% reduction in concentration Granted conditional license in early 2009

26. Field Studies of E. coli SRP Vaccine 2007 field trial in a commercial feedlot – 3 doses or SRP vaccine or 3 doses of placebo – Vaccine efficacy=85%; 98% reduction in concentration Granted conditional license in early 2009

27. Field Studies of E. coli SRP Vaccine 2 industry-initiated studies in 2010 Population intervention studies – Study A 2-dose study 40% reduction in feces No impact observed on hides Associated with reduced total combos of beef trimmings microbially lotted with a positive test – Study B 1-dose study Reduced prevalence in feces at beginning of study 67% reduction in prevalence on hides Only 1 positive combo (in control) so precluded analysis

28. Field Studies of E. coli SRP Vaccine 2 field studies conducted in 2011 – Vaccinates and controls in same feedlots 3-dose study (multiple feedlots) 2-dose study (Renter et al., from K State) 2 cohorts of animals – Pens of vaccinated animals – Non-vaccinated pens – usual feedlot practices In 3-dose study, evidence of effect modification due to need for prerequisite programs

29. 3-dose, multi-feedlot study Sample-level data – No treatment*time interaction (P=0.42) – Significant association with vaccination (P=0.03) 12.3% in controls versus 5.9% in vaccinates VE = 52% over study duration No effect in single feedlot in need prerequisite programs P=0.03 Field Studies of E. coli SRP Vaccine

30. 3-dose, multi-feedlot study Pen-level – Detected in 70.0% of control pens vs 35.0% of vaccinate pens – 50% reduction Random pool of 5 – Detected in 60.0% of control pens vs 15.0% of vaccinate pens – 75% reduction No effect in single feedlot in need prerequisite programs P=0.04 P=0.01 Field Studies of E. coli SRP Vaccine

31. Single feedlot study – Renter et al., K State Two-dose regimen E. coli O157 in feces of 37% of controls compared to 17.4% of vaccinates – 53% reduction Prevalence of high shedders was 4.2% in controls compared to 0.95% of vaccinates – 77% reduction Field Studies of E. coli SRP Vaccine

32. Considered strongest form of evidence support a causal relationship – Snedeker et al. ZPH doi: 10.1111/j.1863-2378.2011.01426 Systematic Review and Meta-analysis Summary measure of vaccine efficacy ~60%

33. Summary of Efficacy Studies A variety of effective pre-harvest technologies have emerged (or emerging). Are not silver bullets but efficacy is detectable and repeatable (prevalence & concentration) 1 Efficacy robust across a variety of settings and study designs. Evidence of a dose response and must also consider pre-requisite programs to set the stage for intervention success 3 SRP® E. coli Bacterial Extract Vaccine conditionally licensed and available. Product has a labeled claim as an aid in the control of E. coli O157 in groups of cattle 2 Efficacy of SRP E. coli O157 vaccine ranged from a low of 40% to a high of 85%. Concentration reduced as well. Is this level of efficacy sufficient to have an Impact? 4

34. Poll Question Results Is E. coli O157 predominantly a food-safety challenge in North American? 1.Yes 2.No

35. An Outcomes Model to Evaluate Risks and Benefits of Escherichia coli Vaccination in Beef Cattle H. Scott Hurd and Sasidhar Malladi College of Veterinary Medicine, Department of Production Animal Medicine Former Deputy Undersecretary of Food Safety, USDA

36. The Need for This Analysis Availability of Vaccine Effective at Reducing On-farm Prevalence Relative Value of Pre-harvest (On-farm) Interventions? Hurdle Technology = “Shotgun” – Not Efficient Vaccine is Not Competitive with Current Post-harvest Interventions Funded by Pfizer Animal Health, 2011

37. Unvaccinated Methods: Mathematical Model “Converts” 0157:H7 Shedding Cattle to Human Illnesses ProductionSlaughterConsumption = Contaminated

38. Vaccinated Methods: Mathematical Model “Converts” 0157:H7 Shedding Cattle to Human Illnesses ProductionSlaughterConsumption = Fewer Contaminated

39. Methods: Three Scenarios Evaluated Additionally, Simulated for Various Levels of Product Adoption by Producers 0%, 40%, 80%, 100% Details of the Scenarios for the Impact of Vaccination on Prevalence and Concentration of E. coli 0157:H7 in Cattle Feces Scenario Percentage Reduction in Feedlot Log 10 CFU/g Reduction in Average E. coli 0157:H7 A801.0 B600.3 C400.3

40. Results: Four Outcome Measures Considered Mean annual number of human E. coli O157:H7 illnesses due to consumption of ground beef from steers and heifers (Public Health) 1 Probability of detecting E. coli O157:H7 per ground beef or ground beef trim sample tested by FSIS (in a 10,000 lb lot) (Regulatory) 2 Mean annual number of events where multiple E. coli 0157:H7 human illnesses (outbreaks) occur due to consumption of ground beef from a single production lot (Outbreak) 3 Mean annual number of a “hot” production lots (hot lot = more than 1,000 E. coli O157:H7 contaminated ground beef servings from a single lot) (Event Days) 4

41. Outcome: Annual Number of E. coli O157:H7 Illnesses Annual 0157 Illnesses by Efficacy an Adoption

42. Discussion of Results: Annual Number of Illnesses If vaccine is 80% effective and used by all producers, the projected number of cases is reduced from 20,000 to 8,000 (60% decrease) However, partial adoption is also useful – 80% effective with 40% adoption  23% reduction in illness – 60% effective with 80% adoption  36% reduction in illness

43. Outcome: Annual E. coli O157:H7 Illnesses Decreases with Adoption Number of E. coli 0157:h7 Illnesses Due to Consumption of Ground Beef from Feedlot Cattle

44. Number of Human Cases Decreases Due to Both Reduced Prevalence and Amount of O157 on the Carcass Reduction of Cattle Prevalence and Concentration on Carcass Fraction Reduction in Prevalence Log CFU/g Reduction in Concentration of E. coli 0157: H7 in Feces Number of Human Cases

45. Outcome: Probability of Detection via FSIS Sampling (Regulatory) Assumed FSIS testing of raw ground beef detects 1 CFU in a 325 g sample Based on average probability of detection per sample tested for different slaughter plants and for different production lots from the same plant Impact of additional industry test and hold is not considered

46. Outcome: Detection by FSIS Probability of Detection via FSIS Testing per Sample of Raw Ground Beef

47. Outcome: Detection by FSIS Probability of Regulatory Positive by Efficacy and Adoption

48. Discussion of Results: Detection by FSIS Full adoption of 80% effective vaccine virtually eliminates chance of FSIS detection (97% reduction) 40% adoption of an 80% effective vaccine results in 37% reduction in probability of detection by FSIS 80% adoption of 60% effective vaccine results in 57% reduction in probability of detection by FSIS

49. Hot Lots

50. Distributions are non-normal ● Prevalence and concentration of E. coli in cattle is not a bell curve ● It is Poisson distributed ● Occasional HIGH levels Poisson Distribution of E. coli Prevalences

51. Why do “Hot Lots” Happen? Prevalence and Concentration are NOT Normally Distributed (Poisson) Cattle PrevalenceCarcass PrevalenceConcentration Event Day

52. Outcome: Hot Lots (>1,000 servings in 10,000# lot) if Produce 16,000 Lots Per Year Annual Number Hot Lots for Large Plant by Efficacy and Adoption

53. Outcome: Hot Lots for a Plant Producing 16,000 Production Lots Per Year Annual Number Hot Lots for Large Plant by Efficacy and Adoption

54. Discussion of Results: Hot Lots All levels of efficacy and adoption reduce the risk to packer Full adoption of 80% effective vaccine virtually eliminates chance of Hot Lots (96% reduction) 40% adoption of an 80% effective vaccine results in 43% reduction in probability of Hot Lots 80% adoption of 60% effective vaccine results in 49% reduction in probability of detection by FSIS What is a 20%, 30%, 40% reduction in risk worth?

55. Annual Hot Lots: Vaccine Reduces Variation and Extreme Doses Box-Whisker Plot Comparison More Variation and More “Event Days” Vaccinated – 40% Scenario Unvaccinated

56. TAIL-END OF HISTOGRAM SHOWING IMPACT OF VACCINATION ON NUMBER OF PRODUCTION LOTS WITH HIGH E. COLI O157 PREVALENCE (>5%) IN 325 GM SAMPLES UnvaccinatedVaccinated 60% Efficacy

57. Summary Analysis included impact of biological variation and uncertainty in parameters Modeled from “farm to fork” using best available scientific data Showed that vaccination reduces: – Human 0157:H7 cases – Risk of FSIS regulatory detection – Frequency and magnitude of “event days” 57

58. QUESTIONS & ANSWERS

59. FOR MORE INFORMATION Guy H Loneragan: guy.loneragan@ttu.eduguy.loneragan@ttu.edu Scott Hurd: shurd@iastate.edushurd@iastate.edu Mike Fielding: mfielding@meatingplace.commfielding@meatingplace.com Webinar recording and PowerPoint presentation will be emailed to you within 48 hours. For more information: www.meatingplace.com/webinars www.meatingplace.com/webinars