Human and veterinary approaches to vaccination
monitoring: What can foot-and-mouth disease
learn from measles?
Theo Knight-Jones, David Paton, Giancarlo Ferrari, Mark Rweyemamu
and Keith Sumption
37th Tanzanian Veterinary Association conference
Arusha, Tanzania
27–29 November 2019

• Evaluation of FMD vaccines traditionally based on:
1. Challenge studies
• Control conditions
• Small numbers and may not represent natural challenge
2. Serological evaluation
– Vaccine matching tests
• Useful but imprecise test
– Post vaccination antibody response
• Useful but sero-positivity may not reflect protection from disease
Traditional methods of FMD vaccine evaluation

Need to consider
Cold chain
Shelf life
Batch variability
Variable animal response
Match with field virus
Time since last vaccinated
Number of doses in lifetime
Level/duration of virus exposure
Start with a good vaccine
Field protection is the
ultimate outcome
Make sure animal is vaccinated
according to schedule

• Failure to vaccinate or a vaccine failure?
Concerned about outbreaks in vaccinated population
1. Are vaccinated animals protected from FMD?
Vaccine effectiveness
2. Are the animals being vaccinated (adequately)?
Vaccine coverage

Vaccine effectiveness
After an outbreak:
Compare incidence in vaccinated and unvaccinated
Vaccinated versus Unvaccinated

Human Vacccine effectiveness studies

Vaccine coverage
India: age-specific vaccine coverage
Data from coverage surveys
measlesDTP1 DTP2 DTP3

Vaccinated
Spring+Autumn
2012
Vaccinated
Autumn 2011+
Spring+Autumn
2012
Protection
threshold
once twice 3 times
2.3
2.4
2
0
Log10 (SP titre)
Autumn mass
vaccination
Vaccinated
Autumn 2012
FMD Post-vaccination immunity

9
FMD Post-vaccination immunity
Protection
threshold
2.3
2.4
2
0
Log10 (SP titre)
Autumn mass
vaccination
• Batch monitoring
• Population immunity – national/zonal survey to reflect expected protection
• Monitor change in immunity with time since vaccination/number of doses

Need to consider
Cold chain
Shelf life
Batch variability
Variable animal response
Match with field virus
Time since last vaccinated
Number of doses in lifetime
Level/duration of virus exposure
Start with a good vaccine
If disease control is to
work everyone must do
there bit
Make sure animal is vaccinated
according to schedule

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