Báo cáo nghiên cứu khoa học " Development of Improved Capability in Support of National Biosecurity for the upport Surveillance and Control of Foot & Mouth Disease in Cattle and Pigs - Milestone 8" pptx

Ministry of Agriculture & Rural Development
Development of Improved Capability in
S
upport of National Biosecurity for the
Surveillance and Control of Foot &
Disease in Cattle and Pigs
FMD Vaccine Efficacy Testing and FMD
Vaccination Recommendations


§
Milestone 8
Resubmission, June 2010

Ministry of Agriculture & Rural Development





Development of Improved Capability in
upport of National Biosecurity for the
Surveillance and Control of Foot &
Disease in Cattle and Pigs


Milestone 8

FMD Vaccine Efficacy Testing and FMD
Vaccination Recommendations




Chris Morrissy


Resubmission, June 2010

Development of Improved Capability in
upport of National Biosecurity for the
Surveillance and Control of Foot &
Mouth
Disease in Cattle and Pigs

FMD Vaccine Efficacy Testing and FMD
Vaccination Recommendations
§

1
Table of Contents


1. Institute Information ____________________________________________ 2
2. Project Abstract ________________________________________________ 3
3. Executive Summary ____________________________________________ 3
4. Progress to date _______________________________________________ 4
4.1 Implementation Highlights [

FMD vaccine efficacy testing and FMD
vaccination recommendations
] ___________________________________ 4
5. Conclusions ___________________________________________________ 8

2

1. Institute Information
Project Name
CARD FMD [072/04VIE]
Vietnamese Institution
Regional Animal Health Centre (RAHO-6)
Ho Chi Minh City
South Vietnam
Vietnamese Project Team Leader
Dr Dong Manh Hoa
Australian Organisation
Australian Animal Health Laboratory
[AAHL] Private Bag 24
Geelong, VIC 3220
Australia
Australian Personnel
Mr Chris Morrissy
Date commenced
01/06/2005
Completion date (original)
01/06/2008
Completion date (revised)

Reporting period
Completed following project completion

Contact Officer(s)
In Australia: Team Leader
Name:

Mr Chris Morrissy
Telephone:

+61 3 5227 5000
Position:

Supervisor Mammalian Virology
Fax:

+61 3 5227 5555
Organisation

Australian Animal Health
Laboratory [AAHL]
Private Bag 24
Geelong, VIC 3220,
Australia
Email:

In Australia: Administrative Contact
Name:

Mr Christopher Morrissy
Telephone:

+61 3 5227 5434
Position:

Patents Contracts Officer
Fax:

+61 3 5227 5555
Organisation

Australian Animal Health
Laboratory [AAHL]
Private Bag 24
Geelong, VIC 3220
Australia
Email:

christopher.morrissy@
csiro.au

In Vietnam
Name:

Dr Dong Manh Hoa
Telephone:

+ 84 8 8568220
Position:

Director
Fax:

+ 84 8 8569050
Organisation

Regional Animal Health Centre
(RAHO-6)
Ho Chi Minh City
South Vietnam
Email:



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2. Project Abstract
The aims of this project were to develop capacity for FMD surveillance and diagnosis
at both a laboratory and field level within the wider animal health network in Vietnam.
Improved diagnostic capacity will facilitate the early detection and identification of FMD
enabling better disease control. Specifically, successful capacity development at
regional laboratories will enable quality assured laboratory capability for FMDV
diagnosis and serology. This will be applied to the investigation of FMDV serotypes
currently in circulation and the reason underlying on-going FMD vaccine failures in
Vietnam. In addition, the successful establishment of an effective laboratory network
for the diagnosis and control of FMD will provide a greater understanding of FMD

epidemiology and will facilitate the coordination and implementation of effective
vaccination control strategies via the wider animal health network in Vietnam.
3. Executive Summary
Significant progress has been made in relation to the achievement of Milestone 8
objectives. Specifically, the acquisition of a database of FMD isolates which has
enabled an evidence-based assessment of the prevalence and risks associated with
individual FMD serotypes in specific regions. This has further facilitated ongoing
surveillance which has demonstrated continual improvement in relation to FMD
vaccine coverage in the field. Of particular significance, two-way communication,
support and collaboration between the RAHO-6 laboratory and field veterinarians has
facilitated highly effective disease diagnosis, surveillance and control. This has
resulted in highly informed science-based recommendations being made to
Department of Animal Health (DAH), field veterinarians and farmers with regard to
the selection of the most appropriate FMD vaccine serotype formulations to be used
in the field. The effectiveness of this approach is clearly evident from the fact that in
southern Vietnam the incidence of FMD outbreaks has fallen continuously during the
course of the project with only one isolated outbreak being reported in the 2009-2010
reporting period.
A central aim of this project was to “highlight the importance of having a laboratory
network to identify what is happening in the field and how to prevent and control
disease outbreaks”. Of particular relevance, in relation to Milestone 8 deliverables,
this project has not only successfully achieved this objective in southern Vietnam but
of equal significance has further highlighted the difficulties anticipated at the outset of
this project with regard to the logistics associated with effective FMD surveillance and
control strategies in the field on a national level. Milestone 8 objectives have been
achieved as a result of successful capacity development in the field of FMD
diagnostic capability in Vietnam. For example, the establishment of full FMD
diagnostic capability at both RAHO-6 and NCVD has, since the initiation of this
project, cumulated in their recognition as FMD Reference Laboratories in Vietnam.
Nevertheless, it is clearly apparent, and foreseen at the initiation of this project, that a

critical component is the close integration, support and communication required
between the newly established FMD Reference laboratories, Regional Laboratories
and related field veterinarians and DAH personnel. This is clearly illustrated by the
implementation strategy at RAHO-6 where successful capability development and
quality assurance in the laboratory was the driving force behind more effective
training and education of field veterinarians in relation to effective FMD management
practices in the field. This was undoubtedly an ambitious project and also subject to
unforeseen circumstances such as AI and PRRSV outbreaks in the field.
Nevertheless, Milestone 8 deliverables have been achieved to varying degrees
throughout Vietnam and with tremendous success in southern Vietnam.

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4. Progress to Date [In relation to Milestone 8 Deliverables]
4.1 Implementation Highlights
[FMD vaccine efficacy testing and FMD vaccination recommendations]
An earlier year-by-year breakdown detailing the FMD serotype[s] in circulation and
the ongoing vaccination history in each province included in the study was given in
the earlier Milestone 6 Report entitled; “Epidemiological and sero-surveillance
programs operational”.
In this Milestone 8 resubmission, each of the specific Milestone Deliverables are
addressed. In addition, each of the specific comments made by the Referees are
discussed in relation to the achievement of project objectives.

• Database of FMD isolates in Vietnam, including incidence and risk
assessment in target villages/districts

Comprehensive FMD diagnostic capacity development at RAHO-6, NCVD, and also
FMD Ag ELISA capability at RAHO-4 & 7, has enabled FMD diagnosis and both
sero-surveillance and the characterisation of FMD field isolates. This used in

conjunction with the successful implementation of the AAHL LP ELISA has facilitated
the determination of vaccine efficacy. In addition, when used in combination with the
AAHL 3ABC ELISA, which can differentiate vaccinated from infected animals, has
allowed the incidence of FMD infection to be determined. Resultant surveillance data
has led to a greater understanding of the incidence of specific serotypes in circulation
in the field in Vietnam, the determination of the efficacy of vaccine coverage and has
facilitated the identification of the risks associated with specific FMD serotypes in
target areas in Vietnam.
During the course of this project sero-surveillance, serotyping and vaccine efficacy
data were collected and collated on an ongoing yearly basis. As an example, data
collected for 2008 are given in Attachment 1. Spreadsheets of yearly data are
available and are used by RAHO-6 and other laboratories as progressive baseline
data from which the effectiveness of this project on completion can be determined
and for future benchmarking. Taken as a whole, the data obtained during the course
of this project has had a very significant impact in relation to the diagnosis,
surveillance and control of FMD in Vietnam. For example, in the 2006/2007 period
the sequencing and genotyping of FMD field isolates was performed and highlighted
the occurrence of the following FMD serotypes in Vietnam:

• Serotype O [3 topotypes]
o Cathay
o ME-SA (Pan Asia)
o SEA
• Serotype A
o Thailand / Malaysa 97


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• Serotype Asia 1

o Jiangsu-China 2005 [North and Central of Vietnam]
o Myanmar 98 [Central Vietnam]

Of particular significance, the ability of FMD Reference Laboratories in Vietnam to
genotype FMD field isolates has already resulted in the refinement of vaccine usage
in the field. For example, the results of this study have driven an evidence-based
change in the serotype composition of FMD vaccine from A 22 to A Malaysia 97 with
a concomitant change in the antigen used for serological tests in Vietnam. In
addition, the inclusion of provinces with borders to Cambodia, Laos and China has
further strengthened Vietnam’s biosecurity by detecting disease incursions [e.g.
confirmation of 2 cases of FMD Asia 1 virus] of serotypes of FMD not previously
detected in Vietnam.
As requested by the Referees, presentations detailing the results of FMD outbreak
investigations and serological surveys covering the period 2005-2008 have been
attached to the earlier Milestone 10 Report. However, for convenience, the CARD
FMD presentations given at the SEAFMD Lower Mekong Working Group in 2008 and
further updated at the SEAFMD LabNet Meeting in 2010 are given as Attachments 2
and 3 to further substantiate this and subsequent Milestone 8 deliverables.
For example, the effectiveness of FMD diagnosis and control measures as a result of
this project are clearly evident from the year-by-year geographic breakdown of
outbreaks in Vietnam and are given in Attachment 2. Specifically, the numbers of
FMD outbreaks have progressively declined during the 2005-2008 period and of
particular significance, there have subsequently been only one isolated FMD
outbreak in South Vietnam in the 2009-2010 reporting period.
These results clearly demonstrate the effectiveness of the coordinated laboratory
diagnosis and disease surveillance conducted by RAHO-6 in relation to the FMD risk
assessment, surveillance and subsequent control using the correct vaccine serotype
composition and serotype specific serological tests in southern Vietnam. Specifically,
the availability of sero-surveillance data in conjunction with direct contact and support
of field veterinarians by RAHO-6 has led to increased vaccine coverage, an improved

response to vaccination in cattle with resultant highly effective control of FMD in the
southern provinces of Vietnam.

• Results of efficacy testing

Vaccine efficacy testing was performed using the AAHL LP ELISA for O, A22, A
Malaysia and the Asia 1 serotype of FMDV. The results from vaccine efficacy testing
demonstrated that the FMD vaccine response rate in cattle surveyed increased from
29% in 2006 to 68% in the second half of 2008 [Attachment 3]. In addition, the
efficacy of vaccine coverage was greater on larger scale commercial cattle farms
where a coverage rate of 90% was observed in 2008.
In smaller farms, sero-surveillance of vaccine efficacy post-vaccination in cattle
consistently demonstrated moderate vaccine coverage with an initial vaccination
response of 60%. In addition, in all small-scale operations the vaccination response
in pigs was much lower at 10%. However, as expected, commercial large-scale
farms achieved a much higher vaccination response both in cattle (90%) and in pigs
(70%). This is a reflection of the difficulties associated with vaccination on smaller
farms where vaccination is not performed to the same level and where animal

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identification and record keeping required for follow-up surveillance of individual
animals is not as straightforward compared to larger scale commercial enterprises.
However, the lower rate of vaccine coverage observed in all pig farms reflects not
only the difficulties associated with animal identification on smaller farms but also the
intrinsic lower immune response elicited post-vaccination of pigs.
The results of vaccine efficacy testing and surveillance in the field have been highly
successful in significantly reducing FMD outbreaks in southern Vietnam. However,
as raised at the SEAFMD LabNet Meeting in 2010, this study also highlighted
shortcomings in relation to how FMD surveillance is being conducted in areas outside

southern Vietnam. Specifically, this project has highlighted the requirement for much
greater communication and coordination on a national level between both DAH
laboratory and field-based personnel.

• Veterinarian and farmer vaccination recommendations

Accurate vaccination recommendations to both veterinarians and farmers are
essential for the diagnosis, surveillance and control of FMD in the field in Vietnam.
During the course of this project, successful laboratory capacity development has
resulted in the attainment of FMD Reference Laboratory status by both RAHO-6 and
NCVD. This has facilitated FMD diagnosis and both the serotyping and genotyping
of FMD field isolates required to enable an informed decision to be made in relation
to the selection of the most appropriate and effective FMD vaccines in Vietnam and
on a region-by-region basis.
The successful implementation of FMD diagnostics, surveillance and control
strategies has already resulted highly effective evidence-based recommendations
being made by DAH in relation to the serotype composition of FMD vaccine to be
used in the field. For example, the change from A 22 to A Malaysia 97 in Vietnam
and the selection of regions that are recommended to use trivalent vaccines
(serotype O, A & Asia 1) and those that are recommended to use divalent vaccines
(either O & A or O and Asia 1).
Of particular significance in relation to making vaccine recommendations to both
veterinarians and farmers, RAHO-6 provides training and advice to other regional
laboratories and DAH personnel in relation to proper sample collection for
surveillance and virus serotype characterisation in the laboratory. The training
comprised initial workshops conducted at the start of the project, on-going OIE
workshops and highly effective on-the-job “hands-on” training of DAH personnel in
the field during the course of the project. The successful reduction of FMD in
southern Vietnam attests to the potential effectiveness of the approach adopted by
RAHO-6 and the likelihood of success when applied in other areas in Vietnam in the

future. However, notwithstanding this achievement, it is acknowledged that
considerable work remains to be done elsewhere in Vietnam to ensure effective
vaccination programs and vaccine recommendations. However, vaccine
recommendations can only be substantiated following laboratory submission and
characterisation of FMD field samples.

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Specific comments made by the Reviewers

1. The earlier milestone 8 Report detailed the provinces that met
submission requirements for each round but no data was included.
o In this Milestone 8 resubmission an example of yearly returns is given
as Attachment 1. As related earlier in this resubmission, all data
collected are available as spreadsheets of yearly returns and are used
as ongoing baseline data in the relevant laboratories. Summary Tables
have been given in the earlier Milestone 6 Report and are further
summarised in the SEAFMD presentations given in 2008 and 2010 and
are also included as Attachments 2 and 3 in this Milestone
resubmission.

2. Efficacy testing of vaccines
o Evidence of efficacy testing of vaccine coverage was mentioned but not
attached to the earlier Milestone 8 Report submission. However,
substantiation is given in this Milestone resubmission, attached
supporting SEAFMD presentations and were also detailed in the earlier
Milestone 6 report.

3. Veterinarian and farmer recommendations for vaccination
o Vaccine recommendations are currently being made by DAH

personnel. This includes the inappropriate use of certain vaccine
serotypes in specific regions and also the stamp-out policy in relation to
incursions of new serotypes of FMD.
o Recommendations in relation to improved vaccination protocols and the
selection of the most appropriate vaccine for use in the field in specific
regions of Vietnam have required the laboratories to maintain constant
contact and feedback with both field veterinarians and farmers. This is
a reiterative process with vaccine recommendations based on the
results ongoing rounds of sero-surveillance and additional laboratory
characterisation of field isolates.

4. Comments in relation to implementation of the project
o The success achieved by RAHO-6 clearly attests to the utility of the
approach adopted. In particular, close integration and communication
of laboratory and field-based DAH personnel at RAHO-6 has led to the
effective diagnosis, surveillance and control of FMD in southern
Vietnam.
o However, we acknowledge that epidemiological and field support at
other locations were lacking and further compounded by recent AI and
PRRSV outbreaks which unfortunately has led to a dilution of effort on
FMD on the part of many regional laboratories and provincial DAH
personnel.
o Nevertheless, the approach adopted has proven its utility and should be
applied in future efforts to control FMD on a national level in Vietnam.

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5. Conclusions
This project has successfully achieved Milestone 8 deliverables via the establishment
of quality assured FMD diagnostic capacity within the network of veterinary

laboratories in Vietnam. In this respect it should be noted that both the HCMC
[RAHO-6] and Hanoi [NCVD] laboratories have attained FMD Reference Laboratory
status and continue to provide FMD diagnostic support, training and FMD vaccination
recommendations to other regional laboratories within the wider animal health
network in Vietnam. In addition, in relation to sustainability, this project has also
successfully established all the core competencies required within a wider animal
health network for the on-going achievement of Milestone 8 deliverables at a regional
level.
However, it comes as no surprise that central to the effective control of FMD, and the
achievement of Milestone 8 deliverables at both a regional and on a national level, is
the closer integration, communication and collaboration of laboratory and field
personnel. Such effective Reference Laboratory engagement with DAH and field
veterinarians was exemplified by the dramatic improvement in sample and data
collection at RAHO-6 during the course of this project. This resulted in more effective
diagnosis, surveillance and control as a consequence of the serotyping and
genotyping of field isolates which has greatly facilitated the evidence-based selection
of the most appropriate vaccine formulation for use in specific regions in Vietnam.
Although Milestone deliverables have been achieved by RAHO-6 on a regional basis
in Vietnam it is nevertheless acknowledged that the other FMD Reference Laboratory
(NCVD) has no epidemiology staff and this inherently results in lower quality field
data. In addition, the unforeseen yet necessary diversion of regional laboratory DAH
personnel and resources in relation to AI and PRRS outbreaks in the north of
Vietnam was also acknowledged by the collaborating laboratories as one of the
contributing factors underlying the failure to fully realise Milestone 8 project
objectives on a national level.
Of particular significance, and notwithstanding the considerable achievements by
RAHO-6 in southern Vietnam, this project has further highlighted the logistic
constraints and additional training / support requirements in relation to the future
implementation of Milestone 8 deliverables as an integral component of FMD control
measures on a national level. Specifically the interdependence of laboratory and

field activities for the realisation of FMD control objectives on a national level. The
lessons learnt from this project are clearly apparent to all the regional laboratories
and the success achieved by RAHO-6 has provided both a lead and strategic
direction to DAH personnel. In addition, the success achieved by RAHO-6 in
southern Vietnam also provides a clear impetus to other regional laboratories in
relation to the requirement for closer integration and greater two-way communication
between laboratory and field personnel.