210 likes | 392 Views
Okti Nadia Poetri. VACCINATION as part of control measures for Highly Pathogenic Avian Influenza (H5N1). 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
E N D
Okti Nadia Poetri VACCINATION as part of control measures for Highly Pathogenic Avian Influenza (H5N1)
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: • SPF layers • Broilers • Back yard chickens • Commercial layers Field studies • Sukabumi field trial • Broiler Study • 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
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