1.
EMERGENCY VACCINATION BENEFITS
ERADICATION OF HYPOTHETICAL
INTRODUCTIONS OF FMD INTO NEW ZEALAND
Zhidong Yu, Robert Sanson, Thomas Rawdon, Katie Owen, Katie
Hickey, Mary van Andel.
By Kylee Walker on behalf of:

2.
Impact of FMD outbreak in New Zealand
• Never had a case of FMD so we know little about how an outbreak would behave in
the New Zealand setting
• Catastrophic for the country
– Market shutdown for animal and animal products
– Loss of $16.2bn over 8 years
– Damage in life style, reputation and many other factors

3.
FMD response policy in New Zealand
• Readiness to response primarily relied on stamping-out
• New policy: considers vaccination as an adjunct tool from the start of an outbreak

4.
Purpose of the study
• Verify benefits of vaccination with extended scenarios
• Understand the key factors affecting the effectiveness of vaccination
• Suggest a practical vaccination strategy based on resources available
• Identify new areas for future study

5.
Study design (1)
• Output indicators:
- Infected Premises (IP) numbers
- Outbreak duration (days)
- Area size under control (AUC)
• Three introduction scenarios:
- Auckland, Taranaki and
Christchurch
• Two levels of stamping-out
efficacy (compliance rates):
- Standard Stamping Out vs
Reduced Stamping Out
• Two vaccination efficacy (herd
immunity) settings.

6.
Study design (2)
• Multiple factors (strategies, start time, etc):
– Starting time: 11, 14, 16, 21, 28 days PD or 50 /100 IPs
– SV and PV with variable zone sizes
– Cattle-only (Taranaki Only)
• Impact of personnel resource
Suppressive
vaccination
Protective
vaccination

7.
Effect of vaccination start time
IP Duration Area under control

8.
Effect of vaccination strategy and zone size
IP Duration Area under control

9.
Vaccine dose requirements

10.
Effects of personnel resource on vaccination
y ~ (1/x) y ~ (1/x)
R2 = 86% R2 = 78%

11.
Key findings summarised
• Prevented run-away epidemics and aided control
• More effective when used early
• More beneficial for larger outbreaks
• Better effect for larger vaccination zone
• Personnel and vaccine resources influenced outcomes
• Cattle-only vaccination promising

12.
Key factors influencing vaccination effects
• Air transmission
• Incursion scenario (location and detection settings)
• Incursion detection time
• Vaccination start day
• Herd immunity setting

13.
Conclusions
• Findings consistent with many early studies - vaccination could benefit disease
control in New Zealand
• 3-5 km PV starting from Day 11-16 recommended

14.
Future studies
• Recommended further studies to support vaccination decision-making:
– cattle-only vaccination,
– personnel resource requirements, and
– early indicators for potential large outbreaks.

15.
Acknowledgements
Andre van Halderen: Contribution in macro-economic modelling and general advice
for this study.