vaccine selection process part 3 -international fmd

Vaccine selection process

Part 3 - International FMD Surveillance

EuFMD Gen Session, Rome, 28th April 2011

Institute for Animal Health

David Paton

Why do it?

• Threat of new outbreaks or epidemics

– changes in range of known strains

– newly emerging strains

– upsurges in cases– upsurges in cases

• Understand origins of outbreaks and extent of

undisclosed infection

• Selection of appropriate controls

– including vaccine selection for local and international control

– some threats matched by existing vaccines and some not


Early warning – time to get vaccines ready?

• Review breadth of cover that can be provided

by existing vaccine strains

• More rigorous assessment of particular strains• More rigorous assessment of particular strains

• Prepare vaccine from pre-existing strains

• Decide on a higher payload/more boosters

• Make a new vaccine from scratch

• Decide against a vaccination policy


Vaccine selection – several processes and players

• Obtaining field information and samples

• Obtaining vaccines and antisera

• Obtaining isolates and evaluating protection


Scenario (1) – vaccine-based control

• e.g. S America, India, China, Turkey

• Established vaccine strains in use

• Target sampling to apparent vaccine failures • Target sampling to apparent vaccine failures

• Match isolates against large panels of vaccine sera

from both once and twice vaccinated animals

• Confirm mismatches by heterologous challenge tests

• Decide on need to change vaccine strain, emergency

vaccination, etc

• Make isolates available to international community


Scenario (2) – free country with vaccine bank

• e.g. Europe, Australia, Japan, N America

• Established vaccine strains in reserves (plus others

with Marketing Authorisation)

• Target sampling to greatest threats, but may be • Target sampling to greatest threats, but may be

difficult to obtain samples

• Match isolates against vaccine sera from bank strains

• Confirm mismatches by heterologous challenge tests

• Decide on need to change vaccine strain, rely on high

potency or not to hold an appropriate reserve


Scenario (3) – endemic without vaccine policy

• e.g. Parts of Africa and South East Asia

• Sporadic vaccination without established strains

• Need to identify suitable vaccine strains• Need to identify suitable vaccine strains

• May need tailored vaccines

• Lack resources for large-scale vaccination

• Reliant on external support for lab work-up

• Local and international interests served by referrals


Current arrangements for vaccine matching

• Regional differences

• South America

– mainly regional referral of samples to PANAFTOSA

• Eurasia and Africa• Eurasia and Africa

– many samples referred to WRLFMD (& others)

• South and East Asia

– diverse arrangements

• Commercial and political interests have an impact

• Few labs undertake matching tests

– OIE/FAO Ref Lab Network - improving integration


~2000 samples from 42 countries

Countries sampled by Ref Lab

2009 Annual Report


In long term

• Local needs met locally

– build up capacity

– simplify technology

• International needs met centrally• International needs met centrally

– unless technology makes this obsolete

– centralised repositories

• Vaccine supply

– manufacture without containment

– improved flexibility of design

– simplified evaluation of protection


In short term

• Build up capacity in primary endemic countries

– training and secondments

– laboratory twinning arrangements

– focused, shared and coordinated effort for impact– focused, shared and coordinated effort for impact

• Develop additional regional centres

– sequencing and phylogeny

– vaccine matching for local vaccine strains

• Synergy with research oriented projects


In short term

• Referral samples

– improve epidemiological information

– pre-screened – Ag ELISA (or LFD) to ensure samples +ve

• Maintain centralised testing for vaccine banks

– more systematic analysis of referred samples

– adequate provision of antisera

• Common web interface for samples and results

• Need an assured vaccine supply

– maintain commercial viability of producers

– regionally specified vaccine strainsInstitute for Animal Health

Recommendations

• Provision for testing from each virus pool:

– 4 samples from each of 5 outbreaks

– 6 countries per pool

– 120 samples per annum per pool

• All confirmed FMDV positive before shipment• All confirmed FMDV positive before shipment

• Original material sent

• Complete P1 sequencing of all isolates at RL

• Representatives matched to all European Bank antigens

• Made available for matching to vaccines held elsewhere

in return for feedback

• Continue integration between ref labs


Thanks for your attention


vaccine selection process part 3 -international fmd

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