The CVOs of Australia, Canada, New Zealand and the USA initiated a scientific review to evaluate if waiting periods to regain OIE status of FMD free not practising vaccination could be 3 months irrespective of whether vaccinate-to-live or vaccinate-to-die policies were applied.
The authors reviewed the following designated areas reflecting their expertise [historical review of waiting periods; Carriers; Vaccinology; DIVA technology; Post Outbreak Surveillance and Animal Products].
Current science supports eligibility to return to OIE status of FMD free country where vaccination is not practised in 3 months following an outbreak where stamping-out and
emergency vaccination using higher potency vaccines are applied irrespective of whether vaccinate-to-live or vaccinate-to-die policies. This assumes aspects of vaccination affecting
population immunity such as insufficient match, inadequate coverage, incorrect storage, application, maternal antibody etc are addressed. The alignment of the 3 month waiting period applies only to animal products as in 2006, the Code restricted export of live vaccinated animals from a FMD free country not practising vaccination. However, countries with OIE status, FMD free country where vaccination is practised may accept vaccinated animals and those with no OIE FMD status should not refuse them as per the OIE Code User Guide Part C a). Bilaterally negotiated additional risk mitigation measures may be needed to meet individual importing countries’ Appropriate Level of Protection (ALOP) as in any application of the Code.
(c) D.Geale / EuFMD (eufmd@fao.org)
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Session 2: Aligning waiting periods for vaccinate-to-live & vaccinate-to-die
1. Aligning Waiting Periods
for
Vaccinate-to-live & Vaccinate-to-die
PLENARY Session II:
FOCUS ON ISSUES AFFECTING FMD
CONTROL IN FMD FREE REGIONS
Project Leader: Dorothy Geale (Canada)
Project Team: Paul Barnett (IAH, Pirbright, United Kingdom)
Grant Clarke (New Zealand)
Jennifer Davis (Australia)
Thomas Kasari (United States)
2. Presentation Outline
Context of the QUAD FMD Project
What did the QUAD FMD Code Project conclude?
What is the rationale for this conclusion?
Historical basis for 3 and 6 months
Vaccinology/Carrier/Subclinical
DIVA
Post Outbreak Surveillance
Animal Products
Conclusion/Recommendations
Next Steps
10/28/2012 2
3. Context
In April, 2011 QUAD CVOs tasked a scientific
literature review to see if support for alignment
of waiting periods for vaccinate-to-live and
vaccinate-to-die strategies
Core Project Team
Desirable Outcomes
Dorothy Geale*of economic impediment Grant Clarke (New
Removal (Canada), Tom Kasari (USA), for vaccinate-to-
Zealand), Jennifer Davis (Australia), Paul Barnett (WRL FMD)
live strategies
Collaboration with IAH, Pirbright
Timely decision making regarding FMD vaccination
International FMD Strategic Reserves NETWORK project;
Global reduction of mass culling of livestock through
Work vaccination in a FMD outbreak Vaccinology, DIVA,
streams History of 3/6 mos,
Post-outbreak Surveillance & Trade in animal product
10/28/2012 3
5. Presentation Outline
Context of the QUAD FMD Project
What did the QUAD FMD Code Project conclude?
What is the rationale for this conclusion?
Historical basis for 3 and 6 months
Vaccinology/Carrier/Subclinical/DIVA
Post Outbreak Surveillance
Animal Products
Conclusions/ Recommendations
Next Steps
10/28/2012 5
6. Conclusion
Alignment for vaccinate-to-live and vaccinate-to-
die is NOT feasible for all commodities
But is feasible for vaccinated animal products
using higher potency FMD vaccines
Incremental risk of vaccinated animal products
can be deemed negligible with additional risk
mitigation measures to meet ALOP.
Note Code Article 8.5.9.1 b) and c), deals ONLY
with animal products not animals which are
restricted by Article 8.5.12 3)
10/28/2012 6
7. Presentation Outline
Context of the QUAD FMD Project
What did the QUAD FMD Code Project conclude?
What is the rationale for this conclusion?
Historical basis for 3 and 6 months
Vaccinology/Carrier/Subclinical/DIVA
Post Outbreak Surveillance
Animal Products
Conclusions/Recommendations
Next Steps
10/28/2012 7
8. Rationale
HISTORICAL:
No specific scientific rationale for OIE waiting periods
Years: achieve-with vacc; without vacc/recover-with vacc; without vacc
Prior to 1992: 2 yr; 3 yr /6 mos
1992-1998: 2 yr; 12 mos/12 mos; 6 mos
Vaccinate-to-live
1998-2002: 2 yr; 12 mos/12 mos; 3 mos; 3mos
2002 to present: 2 yr; 12 mos/6 mos (DIVA); 3mos; 3mos;
6mos (DIVA).
Relative risk determined by SCAD in 6 mos blocks for
free with vacc and 3 mos for free without vacc
Vaccinate-to-live
10/28/2012 8
9. Rationale
VACCINOLOGY:
Higher potency (≥ 6PD50) vaccines protect earlier;
single dose; last longer.
FMDV replication even inhibited in some animals
experimentally proven relationship with potency
Infection chain is broken in 1/2 the time; less FMDV
in environment exponentially = less challenge dose
No unequivocal experimental evidence that
conventional vaccine which protects against disease
also reduces susceptibility to infection, virus
excretion or duration of persistence
10/28/2012 9
10. Rationale
CARRIER:
Anecdotal only; No experimental studies show cattle-
cattle transmission; only SAT2 African buffalo-cattle
Undefined trigger? Strain, serotype & challenge dose
differences?
Modeling with high potency parameters suggests
prevalence of carrier herds is very low 0.2% with one
carrier per herd
Does waiting 6 vs 3 mos make a difference? Perhaps
live animals but for animal products?
10/28/2012 10
11. Rationale
DIVA OR NSP ASSAYS:
PANAFTOSA tests, recognized by OIE, are the
foundation to FMD eradication in South America
High potency vaccines are more purified
DIVA kits available with Se (68-94%) & Sp (97-
98%) but Se improved using tests in series.
DIVA validated at the herd level (appropriate for
products) but lacks Se for individual animal level
(already restrict live vaccinates)
10/28/2012 11
12. Rationale
SURVEILLANCE:
Demonstrate absence of infection impossible in a
vaccinated population (demonstrate is used in
Article 8.5.9.1 c); use “substantiate” for
“demonstrate” as NSP assays lack Se.
Even census surveillance (EU) does not provide
absolute certainty; S Korea used <1% prevalence.
South America 5% @ 95%(follow-up per Code
8.5.49)
Need to change OIE paradigm from waiting time to
Sentinels of limited use due to low transmission
statistical certainty or concept of threshold of
surveillance (long term solution)
10/28/2012 12
13. Rationale
Animal Products: [Commodity based trade]
Risk of FMDV from vaccinated products can
be negligible with risk mitigation measures
Risk of mechanical contamination from
carriers is negligible if correctly processed
Neutralizing antibodies are best guarantee of
the absence of FMDV; No Code for milk from
vaccinates
Embryos are not a risk provided handled as
per IETS Manual (2007)
10/28/2012 13
15. Presentation Outline
Context of the QUAD FMD Project
What did the QUAD FMD Code Project conclude?
What is the rationale for this conclusion?
Historical basis for 3 and 6 months
Vaccinology/Carrier/Subclinical/DIVA
Post Outbreak Surveillance
Animal Products
Conclusions/Recommendations
Next Steps
10/28/2012 15
16. Conclusions (repeat)
Alignment of a 3 month waiting period for vaccinate-to-
live and vaccinate-to-die is feasible provided the
incremental risk of vaccinated animal products is deemed
negligible with additional risk mitigation.
Article 8.5.9.1 b) and c), deals ONLY with animal
products as animals are restricted by Article 8.5.12 3)
Additional risk mitigation measures determined bilaterally
to meet ALOP but may include bovine only (DIVA herd
validated); animal identification & traceabilitiy; protection
zone vaccination only; serology; no wildlife reservoir etc
10/28/2012 16
17. Recommendations
Code needs definitions for “emergency” vaccination,
FMDV “circulation” versus “infection”
OIE convene ad hoc group to define statistical
certainty or threshold ,of surveillance to demonstrate
the absence of FMDV infection and FMDV circulation.
DIVA for higher potency vaccines for all species.
Promote novel vaccine such as marker VP1 gene
segment with duplicate DIVA capability.
Encourage concurrent revision of EU 2003/85/EC.
Article 62 of this Directive permits derogation of the OIE waiting periods of 3 and 6 mos.
provided, “…the clinical and serological survey provided for in Article 56
and the measures provided for in Article 57 have been completed
and confirmed the absence of foot-and-mouth disease virus infection” (EU, 2003).
10/28/2012 17
18. Presentation Outline:
FMD vaccinate-to- live
Context of the QUAD FMD Project
What did the QUAD FMD Code Project conclude?
What is the rationale for this conclusion?
Historical basis for 3 and 6 months
Vaccinology/Carrier/Subclinical/DIVA
Post Outbreak Surveillance
Animal Products
Conclusions/Recommendations
Next Steps
10/28/2012 18
19. Current Status
1. Propose alignment of waiting periods for
vaccinate-to-live and vaccinate-to-die to the
OIE (8.5.9 1. b) & c)
a) Concept presentation was made at July 3-5 ad
hoc FMD Group under SCAD
b) Formal letter to Dr Vallat from QUAD CVOs on
August 1 with revised QUAD paper with scientific
evidence to support Code change
10/28/2012 19
20. Next Steps
c) Tabled at SCAD at
end of August 2012
d) Referred back to ad
hoc FMD Working
Group with written
rationale
e) To be reviewed in
Code Commission
meeting February
2013
10/28/2012 20
21. Next Steps
EU Support ?
A principle conclusion of the EU Tervuren
workshops in 2007 was “Vaccination-to-live
policy with subsequent freedom from
infection substantiated by a survey system
including NSP testing is a realistic and
achievable option in FMD control.”
10/28/2012 21
22. Acknowledgements
QUAD CVOs
Paul Barnett (IAH, NETWORK)- Vaccinology
Grant Clarke (New Zealand) - DIVA
Jennifer Davis (Australia) – Animal Products
Thomas Kasari (United States)- Surveillance
QUAD CVOs
John Clifford (United States)-
Brian Evans/Francine Lord ( Canada)
Mark Schipp (Australia)
Matthew Stone (New Zealand)
Questions?
Technical Reviewers QUAD EMWG Reviewers
Soren Alexandersen Jane Rooney/ Pam Hullinger/Randy Crom/Hernando Duque
Alex Donaldson Tom Smylie/ Jim Clark/ Al Barton/ Randy Morley
Paul Kitching Andre van Halderen/ Katie Owen/ Brendan Pollard
Victor Saraiva Jill Mortier/ Dick Rubira
Keith Sumption
Gavin Thomson
10/28/2012 22