Vaccination of Poultry against HPAI Policies, Issues and Good Practice

A distance learning seminar organized by the World Bank, FAO, OIE and the Tokyo Development Learning Center

Seminar Four

October 17, 2007 (Washington, DC)

Vaccination PlansLogistics, Monitoring and

Other Accompanying Measures

J. Domenech, A. Tripodi, G. DauphinJ. Lubroth, L. Sims

FAO

• Vaccination is one tool among the prevention and control measures for AI and should not be used as a stand-alone measure

• Vaccination will:• reduce the susceptibility of animals to infection • reduce clinical signs and mortality• reduce shedding of virus and thus reduce virus

circulationbut:• logistically demanding • costly • one country = one strategy• monitoring needed• will change the demands on general surveillance

Vaccine types Description

inactivated homologous

H5N1not possible to differentiate vaccinated from infected animals

inactivated heterologous (field strain or reassortant strains)

H subtype same as field strain + different N e.g. H5N2, H5N9 differentiation of vaccinated animals is possible based on anti N Ab (DIVA)

live vectored recombinant (HA gene expressed)

• Trovac®: Fowlpox + H5 component (HA gene) (rFP-H5); Fowlpox+H5&N1 (China)

• ND + H5 (China)

• In ovo: adenovirus + H5 (HA gene) (experimental stage)

reverse genetic inactivated

HPAI field isolates, cleavage site modified. e.g. H5N1 Harbin, H5N3 (Fort Dodge)

Selection of vaccine and strains

Example of vaccination protocol with inactivated vaccine

Layers (from 7 days of age onwards):

d7 after 4 weeks 2 weeks before the onset of laying period

Use of hatchery based prime vaccination with rFP-H5 in validation process in the field

Vaccination Schedules

Example of vaccination protocol with inactivated or live vectored vaccines

Broilers (from 7 days of age onwards):

for inactivated vaccines:from 7 days of age

rFP-H5 vaccine:at day old in hatchery

Vaccination is not recommended later than two weeks before marketing:

o time for immune response too shorto bruises at injection side

Vaccination Schedules

How and by whom is the vaccine distributed?

• Important to decide with involved stakeholders

• Local distribution mechanisms need to be considered:

• Through veterinary services• Through commercial distributors and

their distribution chain (establish monitoring/reporting to the veterinary services)

• Private veterinarians e.g. francophone countries “mandat sanitaire”

• ....

Distribution of vaccines

Control by the veterinary services is highly recommended

• Distribution of vaccines and monitoring Poultry census for calculation of needed doses

• Material:

Automatic syringes

Needles

Disinfectants

PPE

Vaccination forms

Operational Aspects

• Vaccinators for DOC:• 2500 to 3500 chicks/h compared to around

1200/h manually

Cold rooms at central level ensure sufficient space

regular temperature monitoring

ensure continuous power supply

Cold chain

Photos: A. Tripodi

Refrigerators at local level (check available place for AI vaccines)

Vaccine carriers

Biosecurity issues

• Need for training and sufficient material to address biosecurity issues especially during vaccination campaigns:

• Vaccinating teams movements (boot covers? disinfectants? gloves?)

• Vaccination material

• Changing needles

• Cleaning and maintenance of syringes

Human resources

• Contract technicians of industrial/commercial farms

(1000-1200 birds/h)

• Technicians of pharmaceutical/feed companies

• Contracted private veterinarians (e.g. “mandat sanitaire”)

• Animal Health Workers

• for vaccination campaigns:• training of vaccinating and support teams• incentives for vaccinating teams have to be budgeted

Information and Awareness

• provision of information through multi-track communication campaigns to ensure informed decision-making processes and producers’ participation

Information and Awareness

• Information and dialogue with commercial farmers

• Need for information and compliance of the population • information on vaccine and

vaccination schedule

• information on logistics• time of vaccination(s) in the village

• keep the poultry inside/fenced/in baskets

• information about costs/free of charge

• Cooperation of farmers and village heads is crucial for an effective implementation!!!

Post-Vaccination Surveillance

Objectives:

Monitor AI field virus circulation in vaccinated populations

Check upon matching of vaccine strains and field strains to adapt strategy if necessary

How?

Clinical surveillanceSentinel birdsSerological surveys (DIVA, e.g. N Elisa)Market surveys

Post-Vaccination Monitoring

Objectives:

Assessment of vaccination coverage

How? Surveys: Data on vaccinated poultry Post vaccination serology

Financial aspects

• vaccines (0.03 to 0.05 USD/dose)

• syringes (good quality around 30 USD/piece)

• cold chain

• disinfectants/PPE

• operational costs (human resources, transport, monitoring, stationary, fuel for generators..)

• post-vaccination monitoring: laboratory analysis, sampling

• post vaccination surveillance: laboratory analysis, sampling

Operational costs and material

Cost examples:

- Cote d’Ivoire:

0,067 (sectors 1-2) to

0,077 (sectors 3-4)

/ bird / vaccination round

- Vietnam:

0,067 (sectors 1-2) to

0,062 (sectors 3-4)

/ bird / vaccination round

Cost sharing

• Vietnam public sector 75%

• Indonesia public sector 76-78%

• Cote d’Ivoire 47-57%

• Large farms: could pay all costs

• Small scale farms: should be subsidized

• Long term sustainability?

Political support needed

• Political support at the highest level to be obtained

• To be flowed down to the community level with strong communication campaigns support

Duration and Exit Strategy

• The epidemiological situation has to be monitored carefully before an exit strategy can be applied.

• Although it cannot be determined in advance whether the campaign will be successful, an exit strategy should be developed.

• In addition:

• implementation of adequate measures addressing risk factors and re-introduction of the virus