Vaccine security Meeting Rome Italy FAO HQ 23-24 January 2020 Pillar I - Improve\1.3 Emerg Vacc\Vaccine Security Meeting\PPTs final

1. FMD Reference Laboratory
FMDV vaccines:
role of reference laboratories to
provide technical advice for
strain selection
Donald King, Alison Buman, Anna Ludi,
Ginette Wilsden, David Paton,
Nick Mwankpa, Ethel Chitsungo

2. A O
Asia
1
C
SAT
1
SAT
2
SAT
3
[1] Seven FMDV serotypes
[2] Intra-serotypic differences = (changing) antigenic variants
[3] Vaccines from
different producers
= different vaccine
strains, potency,
and formulation
Regional/
national
risks
(viral
topotypes)
Why is vaccine selection not always straight forward?
A
A
A
A
A
O
O
O
O
SAT
1
SAT
1
SAT
1
SAT
2
SAT
2
Asia
1
C
C
C
SAT
3
SAT
3
SAT
3
What is the
value
of these
vaccines
to cover
these risks?
Vaccine B
Vaccine A
SAT
1
A
O
SAT
2
A
O
SAT
2

3. Obvious gaps that cause uncertainty for customers:
1. A wide-range of vaccines (from different producers) are often
proposed for use (in contrast to S. America, India)
2. The quality and performance of FMDV vaccines cannot be easily
assessed through direct testing
3. Homologous/monovalent QA/QC (OIE Manual) vs heterologous
vaccine performance in the field with multivalent products
4. Reference reagents (BVS) that can be shared between
laboratories are often lacking, and there are usually commercial
restrictions on access to vaccine master-seed viruses (for
independent homologous testing)
5. No harmonisation in tests/antigens used to assess post
vaccination responses
6. Lack of direct measures of “protection” for different host species
Vaccine selection for endemic pools

4. A proposal for a way forward?
Testing by FMD Reference Laboratories
• Focus testing to measure heterologous responses
• Using final formulated product supplied to customers
• Use common/standardized FMDV viruses (Antigen Panels)
representative of the antigenic threats in a region
• Adopt standardized protocols for post-vaccination testing
(numbers of animals and sampling time points [including
booster doses])
• In different laboratories, use more harmonized VNT or
(calibrated) ELISA-based methods
Important applied research gaps
• Defining cut-offs
• Application of approach for different host species?

5. • Trial of multivalent vaccines
– in different host species
– oil vs aqueous formulation
– single vs booster schedule
• Heterologous responses (VNT) against
‘reference’ antigens representing lineages
that threaten Mongolia
• No need for vaccine master seed viruses
• Oil-adj vaccines > aqueous-adj vaccines
– Oil vaccines: higher and more persistent titres
especially after two-dose primary course
– lower titres with aqueous vaccines likely require a
booster after 3 months
Ulziibat et al., 2020 Vaccine
Case Study:
Assessment of vaccine performance Mongolia

6. ?

8. Vaccine producers often focus on homologous
responses (according to OIE guidelines)