1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

Samia Metwally (FAO)

Samia.Metwally@fao.org

FMD vaccination and post-

vaccination monitoring guidelines

1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

• Practical guidance on how to evaluate the effectiveness of FMD vaccination programmes

• Tailored to needs of countries at different stages of FMD control

Aims

1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

The Guidelines

What is next?

Pocket guide, training sessions, backstopping

1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

Design Establish clear objectives and targets

Decide which animals to vaccinate

Decide when to vaccinate and boost

Establish a vaccine registration system to evaluate coverage

Supplies for vaccination and PVM (syringes, gloves, blood tubes, records)

personal protective equipment (PPE) for vaccinating and post vaccination monitoring

What tasks should be completed before beginning a vaccination programme?

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

Training Decide who will vaccinate and establish a system of supervision

Establish a vaccine monitoring team

Establish distribution centres and cold chain

Develop standard operating procedures (SOP) for vaccination and farm biosecurity

Make diagnostic test kits available and ensure training of laboratory staff

Resources Procure sufficient funds for vaccine purchase, vaccination, and monitoring

Procure sufficient amounts of vaccine for prophylaxis and emergency

What tasks should be completed before beginning a vaccination programme? (Cont’d)

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

1.Aqueous form

a) Aluminum hydroxide gel or saponin

• Commonly used in cattle, sheep, goat, and buffalo

• Less commonly used in pigs

2. Oil forms

a) Single oil emulsion aka water in oil (W/O) vaccines

• Commonly used in cattle in South America

b) Double oil emulsion (DOE) aka water in oil in water (W/O/W) vaccines

• Commonly used in pigs in Asia

What types of FMD vaccines exist?

Two types of vaccines classified by type of adjuvant:

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

What are the objectives of the vaccination programme?

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3

4

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Maintain FMD freedom • PCP-FMD Stage 4-5 • Vaccination implemented to minimise the FMD incursion from outside

Reduce clinical Incidence • PCP-FMD Stage 2

• Vaccination implemented to reduce FMD clinical outbreaks

Eliminate FMD virus circulation • PCP-FMD Stage 3 • Vaccination as part of a control programme, which includes movement control and

stamping out

Regain FMD freedom • PCP-FMD Stage 4-5 • Vaccination implemented as an emergency measure in order to regain FMD-free

status

1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

Antigenic Match (vaccine strain ↔ field strain) • Cross protection is incomplete within serotypes and subtypes. • Choose a combination of vaccine strains that could induce protective immunity against

one or more circulating virus strains.

How to choose an effective vaccine 1

2

3

Vaccine Potency

Vaccine Schedule • Appropriate vaccination schedule will take into account animal density,

husbandry, contact, and movement patterns of animals.

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

What information should be included in the vaccine tender?

Information requested by the tenderer and provided by the manufacturer should include:

Specify serotypes and strains

- Specify PD50 - Onset and duration of immunity

Request sera for homologous vaccine strains to use as reference standards in serological tests for PVM

Vaccine type

Vaccine approved for target animals

Species

Number of doses and doses per vial

Quantity

Of administration

Route

Type of adjuvant

Adjuvant

Potency

Shelf-life of the vaccine (finished product or batch)

Stability

Reference sera

Per species and age of vaccination

Recommended vaccination schedule

Package inserts and warnings provided in target language

Language

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

How to determine the vaccine coverage?

Vaccine coverage calculations

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑎𝑛𝑖𝑚𝑎𝑙𝑠 𝑣𝑎𝑐𝑐𝑖𝑛𝑎𝑡𝑒𝑑

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑎𝑛𝑖𝑚𝑎𝑙𝑠 𝑒𝑙𝑖𝑔𝑖𝑏𝑙𝑒 𝑓𝑜𝑟 𝑣𝑎𝑐𝑐𝑖𝑛𝑎𝑡𝑖𝑜𝑛 × 100

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑎𝑛𝑖𝑚𝑎𝑙𝑠 𝑣𝑎𝑐𝑐𝑖𝑛𝑎𝑡𝑒𝑑

𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑢𝑠𝑐𝑒𝑝𝑡𝑖𝑏𝑙𝑒 𝑎𝑛𝑖𝑚𝑎𝑙𝑠 𝑖𝑛 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 (𝑒𝑙𝑖𝑔𝑖𝑏𝑙𝑒 + 𝑖𝑛𝑒𝑙𝑖𝑔𝑖𝑏𝑙𝑒) × 100

Equation #1 - Vaccination coverage over the entire susceptible population is calculated by:

Equation #2 - Vaccine coverage on only eligible animals after the last round of vaccination is calculated by:

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

– Methodology #1: Estimates proportion of animals vaccinated for the

first time.

– Methodology #2: Estimates the proportion of animals with a

detectable level of antibodies in a population (identifies population immunity at the individual animal level)

– Methodology #3: Monitor immune response at herd level. Estimates the proportion of animals not adequately vaccinated

How to assess population immunity?

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

How to investigate outbreaks in vaccinated animals?

The following is a systemic approach to four different:

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Introduction of new virus with poor match to vaccine strains

• Conduct field investigation and laboratory confirmation

Vaccine contaminated with live FMD virus • Conduct innocuity testing in remaining vaccine batch

• Report to manufacturer if confirmed

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

How do to investigate outbreaks in vaccinated animals?

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c)Vaccine application

• Vaccination schedule (lapse in interval of vaccinations)

• Low vaccination coverage

• Breach in maintaining cold chain

d) Serological test used for PVM analysis

• Low test specificity – false positive

• Misinterpretation of lab results

• Untrained laboratory staff

e) Overwhelming challenge due to lack of other FMD controls

a) Host factors

• Age of vaccinates (young animals received one vaccine dose)

• Health condition (stress, malnutrition, infection)

• Time of last vaccination

b) Vaccine characteristics

• Low potency

• Unstable

• Past recommended shelf life

Failure in vaccination programme in presence of active virus circulation. Possible contributing factors listed below:

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1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

• Batch testing of new vaccine

• Select an appropriate location and source of animals

• Consider vaccination schedule

• Obtain NSP and SP ELISA

• Enlist reference laboratory assistance if needed

• Vaccinate a group of animals

• Follow antibody development over time

• Evaluate vaccine quality

• Calibrate PVM tests

Local Immunity Testing

1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

• How will you ensure quality of vaccines used?

• How will you monitor the effectiveness of your vaccination programmes?

• What are the main priorities to enable countries to evaluate the vaccine effectiveness?

Breakout Group

1st West Eurasia FMD Epidemiology & Laboratory Networks Meeting, Tbilisi, Georgia, 18-20 September

Thank you for your attention