Hematology of common carp following DNA vaccination and koi herpesvirus challenge test

The study was aimed to determine the effectiveness of DNA vaccine doses on hematological aspect which represent immune response and its influence on common carp survival rate. DNA vaccines encoding the viral glycoprotein of  koi herpesvirus (KHV) have been proved to highly protect the fish under laboratory condition.  A dose of 12.5 µg/100 µl vaccine had resulted in a survival rate of 96.67 % during 30 days after challenge test with a lethal dose of KHV. Fish vaccinated using lower doses, i.e. 2.5 and 7.5 µg/100µl showed 100% mortality after 15 and 19 days challenge test respectively, whereas non vaccinated fish as a control showed 100% mortality after 17 days challenge test.  Total leucocytes of the vaccinated fish were higher than control until 42 days post vaccination, but declined afterward.  Phagocytic index of the vaccinated fish using 12.5 µg/100 µl was declined after 49 days post vaccination or 7 days post challenge test. Key words: DNA vaccine, Koi herpesvirus (KHV), leucocyte, phagocytic index, Cyprinus carpio   ABSTRAK Penelitian ini bertujuan untuk menguji pengaruh vaksinasi menggunakan vaksin DNA dengan dosis berbeda terhadap gambaran darah ikan sebagai respresentasi tanggap kebal ikan mas serta pengaruhnya terhadap tingkat kelangsungan hidup ikan mas. Vaksin DNA penyandi glikoprotein koi herpesvirus (KHV) dapat memberikan proteksi yang tinggi pada percobaan skala laboratorium.  Vaksinasi dengan dosis 12,5 µg/100µl dapat mempertahankan kelangsungan hidup sebesar 96,67% selama satu bulan setelah uji tantang dengan virus KHV menggunakan dosis letal.  Ikan yang divaksin dengan dosis yang lebih rendah yaitu 2,5 dan 7,5 µg/100µl mengalami kematian total berturut-turut setelah 15 dan  19 hari uji tantang, sedangkan ikan kontrol yang tidak divaksin mengalami kematian total setelah 17 hari uji tantang.  Jumlah leukosit total ikan yang divaksinasi lebih tinggi dibanding dengan kontrol sampai hari ke-42, setelah itu mengalami penurunan.  Indeks fagositosis ikan yang divaksin dengan dosis 12,5 µg/100µl mengalami penurunan setelah hari ke-49 atau 7 hari setelah uji tantang. Kata kunci: Vaksin DNA, Koi herpesvirus (KHV), leukosit, indeks fagositosis, Cyprinus carpi

Deteksi virus avian influenza (H5N1) pada unggas air dengan uji Haemagglutination Inhibition (HI) dan Reserse Transcriptase-Polymerase Chain Reaction (RT-PCR) di Propinsi Lampung

The objective of this research is to examine the presence of antibody of avian influenza (AI) H5 and detection of genetic material the subtype of AI virus (H5N1) in waterfowls in Lampung Province. Samples consisted of 673 serum and 673 cloacal swabs, and collected from water fowls Epidemiologycally, samples collection were performed by using multistage sampling method. Examination of AI antibodies by Haemagglutination Inhibition test (HI test) demonstrated that H5 antibodies were found at all district in Lampung Province. High frequency of antibodies were noted at district ofo Tulang Bawang (69.41%). The average of antibody titres of AI were low (under 24) and the lowest antibody titre was found at district of Tulang Bawang (20.92). Evaluation of genetic material H5N1 individually by using Reverse Transcriptase – Polymerase Chain Reaction (RT-PCR) was not found among water fowls. The results showed H5 and unknown N subtype (H5Nx); the second subtype was unknown H and N1 (HxN1). Key words: Avian Influenza, Haemagglutination Inhibition (HI), Reverse Transcriptase Polymerase Chain Reaction (RT-PCR

Waterfowl potential as resevoirs of high pathogenic avian influenza H5N1 viruses

The high population of waterfowl subsequently with the high case fatality of poultry and people in West Java regency caused by HPAI H5N1 can raise possibility that waterfowl was a natural reservoir. This research aimed to prove that waterfowl in West Java served as reservoir of AI virus (primarily H5N1) and also identify the virus pathotype based on cleavage site of amino acid sequence. Cloacal swab sample was obtained from healthy and unvaccinated waterfowl from Sukabumi and Bogor Regency. Cloacal swab was propagated in 9 days old embryonic chicken eggs. Allantoic fluid was harvested at the 4th day of incubation and then tested for hemagglutination, and positive isolate continued with virus sub-typing using PCR method. H5 gene from H5N1 isolate then sequenced using dideoxy termination method. Multiple alignment of nucleotide sequences were analysed using MEGA-3.1 program. Sub-typing using PCR method indicated the existence of 25 strain H5N1, 16 strain HxN1, 4 strain H5Nx and 9 virus ND. Characterization of cleavage site amino acid sequence indicated that all H5N1 sample were pathogenic with sequence QRERRRKKR (23 sample) dan QRESRRKKR (2 sample). Waterfowl was HPAI H5N1 virus reservoir. Asymptomatic infection in waterfowl, but the virus shedding gradually occurred and therefore it became potential source of H5N1 virus infection. Our findings suggest that immediate action is needed to prevent the transmission of highly pathogenic avian influenza viruses from the apparently healthy waterfowl into terrestrial poultry or human

Waterfowl potential as resevoirs of high pathogenic avian influenza H5N1 viruses

The high population of waterfowl subsequently with the high case fatality of poultry and people in West Java regency caused by HPAI H5N1 can raise possibility that waterfowl was a natural reservoir. This research aimed to prove that waterfowl in West Java served as reservoir of AI virus (primarily H5N1) and also identify the virus pathotype based on cleavage site of amino acid sequence. Cloacal swab sample was obtained from healthy and unvaccinated waterfowl from Sukabumi and Bogor Regency. Cloacal swab was propagated in 9 days old embryonic chicken eggs. Allantoic fluid was harvested at the 4th day of incubation and then tested for hemagglutination, and positive isolate continued with virus sub-typing using PCR method. H5 gene from H5N1 isolate then sequenced using dideoxy termination method. Multiple alignment of nucleotide sequences were analysed using MEGA-3.1 program. Sub-typing using PCR method indicated the existence of 25 strain H5N1, 16 strain HxN1, 4 strain H5Nx and 9 virus ND. Characterization of cleavage site amino acid sequence indicated that all H5N1 sample were pathogenic with sequence QRERRRKKR (23 sample) dan QRESRRKKR (2 sample). Waterfowl was HPAI H5N1 virus reservoir. Asymptomatic infection in waterfowl, but the virus shedding gradually occurred and therefore it became potential source of H5N1 virus infection. Our findings suggest that immediate action is needed to prevent the transmission of highly pathogenic avian influenza viruses from the apparently healthy waterfowl into terrestrial poultry or human. Key Words: HPAI, H5N1, Reservoir, Water Fow

An inactivated H5N2 vaccine reduces transmission of highly pathogenic H5N1 avian influenza virus among native chickens

Vaccination against H5N1 highly pathogenic avian influenza in endemically affected areas is a potentially attractive option for local prevention and control. In Indonesia the majority of local outbreaks have occurred in back yard flocks with native chickens. and it is therefore of interest to determine whether these birds can be protected against infection by vaccination. To this end two transmission experiments Were carried Out with H5N1 virus (A/chicken/Legok/2003) in vaccinated and unvaccinated native chickens. The vaccine contained an inactivated heterologous H5N2 strain (A/turkey/England/N28/73 H5N2). Birds were vaccinated at 4 and 7 weeks of age and challenged at 10 weeks of age. During 10 days post-challenge tracheal and cloacal swabs were taken for virus isolation, and serum blood was collected regularly to measure haemaglutinin inhibiting (HI) antibody responses. The results show that transmission of H5N1 virus was rapid and efficient ill Unvaccinated birds, that infection and transmission were completely prevented in vaccinated birds, and that vaccinated birds that were exposed to unvaccinated inoculated birds were still Protected from infection. These findings indicate that vaccination with a heterologous H5N2 vaccine is able to prevent virus transmission in flocks of native chickens

Experimental and Field Results Regarding Immunity Induced by a Recombinant Turkey Herpesvirus H5 Vector Vaccine Against H5N1 and Other H5 Highly Pathogenic Avian Influenza Virus Challenges.

&lt;p&gt;Vaccination against H5N1 highly pathogenic avian influenza (AI) virus (HPAIV) is one of the possible complementary means available for affected countries to control AI when the disease has become, or with a high risk of becoming, endemic. Efficacy of the vaccination against AI relies essentially, but not exclusively, on the capacity of the vaccine to induce immunity against the targeted virus (which is prone to undergo antigenic variations), as well as its capacity to overcome interference with maternal immunity transmitted by immunized breeding hens to their progeny. This property of the vaccine is a prerequisite for its administration at the hatchery, which assures higher and more reliable vaccine coverage of the populations than vaccination at the farm. A recombinant vector vaccine (Vectormune® AI), based on turkey herpesvirus expressing the hemagglutinin gene of an H5N1 HPAIV as an insert, has been used in several experiments conducted in different research laboratories, as well as in controlled field trials. The results have demonstrated a high degree of homologous and cross protection against different genetic clades of the H5N1 HPAIV. Furthermore, vaccine-induced immunity was not impaired by the presence of passive immunity, but on the contrary, cumulated with it for improved early protection. The demonstrated levels of protection against the different challenge viruses exhibited variations in terms of postchallenge mortality, as well as challenge virus shedding. The data presented here highlight the advantages of this vaccine as a useful and reliable tool to complement biosecurity and sanitary policies for better controlling the disease due to HPAIV of H5 subtypes, when the vaccination is applied as a control measure.&lt;/p&gt;</p