VACCINATION as part of control measures for

Highly Pathogenic Avian Influenza (H5N1)

Okti Nadia Poetri

HPAI H5N1 in Indonesia

• HPAI H5N1 outbreaks in Indonesia since 2003• Virus is present in 31 out of 33 provinces• Economic losses: US$ 470 million• 149 died human cases; 179 confirmed human cases

(WHO 14 October 2011)• The Indonesian government introduced a policy of

vaccination as part of nine point plan for the eradication of HPAI H5N1 in June 2004

Aim of AI Vaccination

• Reduction of clinical signs, prevention of production losses

• Reduction of virus spread in and between flocks eradication of virus

AI Vaccination

• Vaccines have been used since 2004• Vaccine manufacturers improved their vaccines• Outbreaks of AI still occur

• Possible explanations : – Poor vaccine quality– Poor biosecurity– Poor administration of vaccines– Spread from back yard poultry– Evolution of virus strains

Determination of vaccine efficacy

• Research questions in IDP project:– Are locally produced vaccines of sufficient quality to

prevent transmission in vaccinated layers ? – What is the association between vaccine induced

antibody titers and protection against virus spread ? – Is vaccination of broilers effective ? – Can back yard poultry be vaccinated properly ? – Is vaccination of layers applied under field conditions

effective ?

Vaccine studies

Transmission experiments:1. SPF layers2. Broilers3. Back yard chickens4. Commercial layers

Field studies1. Sukabumi field trial2. Broiler Study3. Vaccine effectiveness study in layer

Presentation of results

• Transmission studies– Are locally produced vaccines of sufficient quality to

prevent transmission in vaccinated layers ? – Is vaccination of broilers effective ? – Can back yard poultry be vaccinated properly ?

• Field study– Is vaccination of layers applied under field conditions

effective ?

Experimental transmission studies

• Vaccinated and unvaccinated control groups• Challenge with H5N1 of half of each group• Contact exposure of other half of a group of birds• Measuring virus shedding, HI titers and spread of

virus from challenged to contact birds

1. SPF-Layer Chickens

• Research question– Can locally produced vaccines reduce virus transmission in

vaccinated flocks ?

• Results– No virus excretion challenged birds– No clinical signs– No contact infections: no virus transmission

• Conclusion– It should be possible to eradicate virus in a group of

properly vaccinated layer chickens

2. Broilers• Research questions:– Can vaccination reduce virus transmission

amongst broilers• Results– Low HI antibody titer after vaccination– Virus shedding and transmission in unvaccinated

as well as in the vaccinated groups• Conclusion– Vaccination of broilers is not effective

• The results are consistent with field data

3. Ayam kampung• Research questions:– Can Ayam Kampung be effectively vaccinated ?– Are Ayam Kampung birds susceptible for challenge with

HPAI virus ?• Results– Vaccinated birds developed high HI titers after vaccination– Unvaccinated birds were susceptible for infection– No viral transmission was observed in vaccinated birds

• Conclusions– Ayam kampung can be vaccinated effectively– Ayam kampung are susceptible for infection with H5N1– Ayam kampung are most likely no silent spreaders of virus,

no clinically healthy virus shedders

3. Ayam kampung• Relation with other data• Field data show poor responses after vaccination

(Sukabumi trial) in ayam kampung– low HI titers– non-responders

• Explanations– no booster– poor administration

Sukabumi field trial :Vaccination of Layer Chicken

• Clinical trial– 6 flocks in treatment group: vaccination according

protocol– 6 flocks in control group: vaccination status unknown– DIVA principle based on sentinels

• Results– Layers had high HI titers– Vaccination coverage > 70%– No outbreaks during one year: sentinels did not become

infected

Sukabumi field trial :Vaccination of Layer Chicken

• Conclusions– Layer chicken in field condition can be properly vaccinated– Farmers reluctant to accept sentinels as indicator of virus

circulation

Conclusions of vaccine research

• Layer vaccination seems effective under experimental condition and also in the field if done in an adequate way

• Broiler vaccination is not effective• Backyard poultry can respond to vaccination, and

transmission can be reduced under experimental conditions, but responses in a field situation are generally poor

• Sentinels can be used to determine virus circulation• Vaccination programs need to be supplemented with

other intervention measures

Contribution IDP project

IDP vaccine studies

• The results of the studies provide information for government and manufacturers of the efficacy of locally produced vaccines and efficiency of AI vaccination in layers, broilers and back yard poultry

• The result of the studies may give input for policy making on improving AI control programmes in Indonesia

IDP-supported vaccine studies

• Operational research (ILRI) / sero-monitoring in back yard poultry

• Vaccine testing in BBPMSOH• Participation in OFFLU project

Veterinary infrastructure

• Gaining knowledge for veterinary service in Indonesia and veterinarians in commercial poultry industry

• Improving capacity building in epidemiological skills of veterinarians involved in vaccine research

• Laboratory improvement• Support for vaccine manufacturers

Participants• CMU• BBPMSOH (NVDAL)• IPB-FKH• CIVAS• CVI-Lelystad• Utrecht University Veterinary faculty• Animal Health Service Deventer• PT. Medion• PT. Vaksindo• Dinas Peternakan Provinsi Jawa Barat• Cikole laboratory Financed by Dutch Ministry of Economic affairs, Agriculture

and Innovation

THANK YOU