51
|
Comparative efficacy of North American and antigenically matched reverse genetics derived H5N9 DIVA marker vaccines against highly pathogenic Asian H5N1 avian influenza viruses in chickens. Vaccine 2009; 27:6247-60. [DOI: 10.1016/j.vaccine.2009.07.110] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 07/10/2009] [Accepted: 07/30/2009] [Indexed: 11/18/2022]
|
52
|
Avian influenza vaccines and therapies for poultry. Comp Immunol Microbiol Infect Dis 2009; 32:351-63. [DOI: 10.1016/j.cimid.2008.01.006] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2008] [Indexed: 11/19/2022]
|
53
|
Pavlova SP, Veits J, Mettenleiter TC, Fuchs W. Live vaccination with an H5-hemagglutinin-expressing infectious laryngotracheitis virus recombinant protects chickens against different highly pathogenic avian influenza viruses of the H5 subtype. Vaccine 2009; 27:5085-90. [PMID: 19573638 DOI: 10.1016/j.vaccine.2009.06.048] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 05/05/2009] [Accepted: 06/10/2009] [Indexed: 12/28/2022]
Abstract
Recently, we described an infectious laryngotracheitis virus (ILTV, gallid herpesvirus 1) recombinant, which had been attenuated by deletion of the viral dUTPase gene UL50, and abundantly expressed the hemagglutinin (HA) gene of a H5N1 type highly pathogenic avian influenza virus (HPAIV) of Vietnamese origin. In the present study, efficacy of this vectored vaccine (ILTV-DeltaUL50IH5V) against different H5 HPAIV was evaluated in 6-week-old chickens. After a single ocular immunization all animals developed HA-specific antibodies, and were protected against lethal infection not only with the homologous HPAIV isolate A/duck/Vietnam/TG24-01/2005 (H5N1, clade 1, hemagglutinin amino acid sequence identity 100%), but also with heterologous HPAIV A/swan/Germany/R65/2006 (H5N1, clade 2.2, identity 96.1%) or HPAIV A/chicken/Italy/8/98 (H5N2, identity 93.8%). No symptoms of disease were observed after challenge with the H5N1 viruses, and only 20% of H5N2 challenged animals developed minimal clinical signs. Real-time RT-PCR analyses of oropharyngeal swabs revealed limited challenge virus replication, but the almost complete absence of HPAIV RNA from cloacal swabs indicated that no generalized infections occurred. Thus, unlike several previous vectors, ILTV-DeltaUL50IH5V was able to protect chickens against different HPAIV isolates of the H5 subtype. Vaccination with HA-expressing ILTV also allowed differentiation of immunized from AIV-infected animals by serological tests for antibodies against influenza virus nucleoprotein.
Collapse
Affiliation(s)
- Sophia P Pavlova
- Institute of Molecular Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald - Insel Riems, Germany
| | | | | | | |
Collapse
|
54
|
Field assessment of an H5N1 inactivated vaccine in chickens and ducks in Lao PDR. Arch Virol 2009; 154:939-44. [PMID: 19458904 DOI: 10.1007/s00705-009-0385-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 04/15/2009] [Indexed: 10/20/2022]
Abstract
Despite the extensive use of poultry vaccines to control the spread of H5N1 influenza in poultry, H5N1 outbreaks continue to occur in domestic birds. Our objective was to determine the duration of the neutralizing antibody response under field conditions after vaccination with a laboratory-tested inactivated reverse genetics-derived H5N3 vaccine. H5N3 hemagglutination inhibition (HI) and virus neutralization (VN) antibodies were observed 40 weeks after vaccination of chickens with two doses and vaccination of ducks with one dose. Cross-clade antibodies to an H5N1 virus (A/chicken/Laos/A0464/07) antigenically distinct from the vaccine strain were detected in ducks after a single vaccination and were sustained for 28 weeks (for 40 weeks when a boost vaccination was given). Our results indicate that this inactivated H5N3 vaccine can produce long-lasting antibodies to homologous and heterologous viruses under field conditions.
Collapse
|
55
|
Song MS, Oh TK, Pascua PNQ, Moon HJ, Lee JH, Baek YH, Woo KJ, Yoon Y, Sung MH, Poo H, Kim CJ, Choi YK. Investigation of the biological indicator for vaccine efficacy against highly pathogenic avian influenza (HPAI) H5N1 virus challenge in mice and ferrets. Vaccine 2009; 27:3145-52. [PMID: 19446184 DOI: 10.1016/j.vaccine.2009.03.061] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2008] [Revised: 03/13/2009] [Accepted: 03/23/2009] [Indexed: 10/20/2022]
Abstract
To investigate the biological indicator for vaccine efficacy against HPAI H5N1 virus challenge of varying clades, two inactivated whole-virus H5N1 vaccines containing the hemagglutinin (HA) and neuraminidase (NA) genes of either clade 2.2 A/EM/Korea/W149/06 (RgKoreaW149/06 x PR8) or clade 2.5 A/Ck/Korea/ES/03 (RgKoreaES223N/03XPR8) virus in the background of A/PR/8/34 (H1N1) were generated by reverse genetics. Administration of the vaccines (2-dose 1.77, 3.5, 7.5 or 15microg of HA) elicited high HI titers in a dose-dependent manner. Mice immunized with RgKoreaW149/06 x PR8 were completely protected from challenge against wild-type A/EM/Korea/W149/06 without clinical signs of infection. RgKoreaES223N/03XPR8 could not protect mice at 1.77microg while all immunized ferrets were completely protected. Two-dose (7.5microg) vaccinated mice (HI titer > or =320) and triple dose (7.5 microg) vaccinated ferrets with RgKoreaES223N/03xPR8 (HI titer > or =640) protected vaccine recipients from mortality, inhibited nasal virus shedding and limited influenza virus tropism. Thus, these vaccines provided cross-protectivity in both models. More importantly, these results collectively suggested a positive correlation between vaccine-induced HI titers and inhibition of virus shedding including block of viral proliferation in major organs against a heterologous HPAI H5N1 virus. Although developing technologies or methods that will enable the reduction of administration dose/frequency remains to be resolved, our study demonstrated a considerable biological marker (> or =640 HI titer) for full protection of the vaccinated hosts that could provide a preliminary basis for the assessment of complete immunization.
Collapse
Affiliation(s)
- Min-Suk Song
- College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju 361-763, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
56
|
Patel JR, Heldens JGM. Immunoprophylaxis against important virus disease of horses, farm animals and birds. Vaccine 2009; 27:1797-1810. [PMID: 19402200 PMCID: PMC7130586 DOI: 10.1016/j.vaccine.2008.12.063] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 11/24/2008] [Accepted: 12/18/2008] [Indexed: 01/31/2023]
Abstract
Since the refinement of tissue culture techniques for virus isolation and propagation from the mid 1960s onwards, veterinary virology has received much academic and industrial interest, and has now become a major global industry largely centred on vaccine development against economically important virus diseases of food animals. Bio-tech approaches have been widely used for improved vaccines development. While many viral diseases are controlled through vaccination, many still lack safe and efficacious vaccines. Additional challenges faced by academia, industry and governments are likely to come from viruses jumping species and also from the emergence of virulent variants of established viruses due to natural mutations. Also viral ecology is changing as the respective vectors adapt to new habitats as has been shown in the recent incursion by bluetongue virus into Europe. In this paper the current vaccines for livestock, horses and birds are described in a species by species order. The new promising bio-tech approaches using reverse genetics, non-replicating viral vectors, alpha virus vectors and genetic vaccines in conjunction with better adjuvants and better ways of vaccine delivery are discussed as well
Collapse
Affiliation(s)
- J R Patel
- JAS Biologicals Limited, The Centre for Veterinary Science, Madingley Road, Cambridge, CB3 0ES, UK.
| | | |
Collapse
|
57
|
Poetri ON, Bouma A, Murtini S, Claassen I, Koch G, Soejoedono RD, Stegeman JA, van Boven M. An inactivated H5N2 vaccine reduces transmission of highly pathogenic H5N1 avian influenza virus among native chickens. Vaccine 2009; 27:2864-9. [PMID: 19428896 DOI: 10.1016/j.vaccine.2009.02.085] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 02/18/2009] [Accepted: 02/24/2009] [Indexed: 11/15/2022]
Abstract
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 in 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.
Collapse
Affiliation(s)
- O N Poetri
- Faculty of Veterinary Medicine, Department of Infectious Diseases and Public Health, Bogor Institute of Agriculture, Bogor, Java, Indonesia
| | | | | | | | | | | | | | | |
Collapse
|
58
|
Bouma A, Claassen I, Natih K, Klinkenberg D, Donnelly CA, Koch G, van Boven M. Estimation of transmission parameters of H5N1 avian influenza virus in chickens. PLoS Pathog 2009; 5:e1000281. [PMID: 19180190 PMCID: PMC2627927 DOI: 10.1371/journal.ppat.1000281] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 12/26/2008] [Indexed: 11/25/2022] Open
Abstract
Despite considerable research efforts, little is yet known about key epidemiological parameters of H5N1 highly pathogenic influenza viruses in their avian hosts. Here we show how these parameters can be estimated using a limited number of birds in experimental transmission studies. Our quantitative estimates, based on Bayesian methods of inference, reveal that (i) the period of latency of H5N1 influenza virus in unvaccinated chickens is short (mean: 0.24 days; 95% credible interval: 0.099–0.48 days); (ii) the infectious period of H5N1 virus in unvaccinated chickens is approximately 2 days (mean: 2.1 days; 95%CI: 1.8–2.3 days); (iii) the reproduction number of H5N1 virus in unvaccinated chickens need not be high (mean: 1.6; 95%CI: 0.90–2.5), although the virus is expected to spread rapidly because it has a short generation interval in unvaccinated chickens (mean: 1.3 days; 95%CI: 1.0–1.5 days); and (iv) vaccination with genetically and antigenically distant H5N2 vaccines can effectively halt transmission. Simulations based on the estimated parameters indicate that herd immunity may be obtained if at least 80% of chickens in a flock are vaccinated. We discuss the implications for the control of H5N1 avian influenza virus in areas where it is endemic. Outbreaks of highly pathogenic H5N1 avian influenza in poultry first occurred in China in 1996. Since that time, the virus has become endemic in Asia, and has been the cause of outbreaks in Africa and Europe. Although many aspects of H5N1 virus biology have been studied in detail, surprisingly little is known about the key epidemiological parameters of the virus in its avian hosts (the length of time from infection until a bird becomes infectious, the duration of infectiousness, how many birds each infectious bird will infect). In this paper we show, using experimental transmission studies with unvaccinated and vaccinated chickens, that H5N1 avian influenza induces a short duration of infectiousness (∼2 days) and a very short period of time from infection until infectiousness (∼0.25 day) in unvaccinated chickens. Furthermore, while transmission was efficient among unvaccinated birds, no bird-to-bird transmission was observed in vaccinated chickens. Our results indicate that it may be difficult to curb outbreaks by vaccination after an introduction in a flock has been detected. On the other hand, preventive vaccination could be effective in preventing virus introductions and limiting the size of outbreaks.
Collapse
Affiliation(s)
- Annemarie Bouma
- Faculty of Veterinary Medicine, Utrecht University, The Netherlands
| | - Ivo Claassen
- Central Veterinary Institute, Wageningen University and Research Centre, The Netherlands
| | - Ketut Natih
- National Veterinary Drug Assay Laboratory, Bogor, Indonesia
| | - Don Klinkenberg
- Faculty of Veterinary Medicine, Utrecht University, The Netherlands
| | - Christl A. Donnelly
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Guus Koch
- Central Veterinary Institute, Wageningen University and Research Centre, The Netherlands
| | - Michiel van Boven
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, The Netherlands
- * E-mail:
| |
Collapse
|
59
|
Spickler AR, Trampel DW, Roth JA. The onset of virus shedding and clinical signs in chickens infected with high-pathogenicity and low-pathogenicity avian influenza viruses. Avian Pathol 2009; 37:555-77. [PMID: 19023755 DOI: 10.1080/03079450802499118] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Some avian influenza viruses may be transmissible to mammals by ingestion. Cats and dogs have been infected by H5N1 avian influenza viruses when they ate raw poultry, and two human H5N1 infections were linked to the ingestion of uncooked duck blood. The possibility of zoonotic influenza from exposure to raw poultry products raises concerns about flocks with unrecognized infections. The present review examines the onset of virus shedding and the development of clinical signs for a variety of avian influenza viruses in chickens. In experimentally infected birds, some high-pathogenicity avian influenza (HPAI) and low-pathogenicity avian influenza (LPAI) viruses can occur in faeces and respiratory secretions as early as 1 to 2 days after inoculation. Some HPAI viruses have also been found in meat 1 day after inoculation and in eggs after 3 days. There is no evidence that LPAI viruses can be found in meat, and the risk of their occurrence in eggs is poorly understood. Studies in experimentally infected birds suggest that clinical signs usually develop within a few days of virus shedding; however, some models and outbreak descriptions suggest that clinical signs may not become evident for a week or more in some H5 or H7 HPAI-infected flocks. During this time, avian influenza viruses might be found in poultry products. LPAI viruses can be shed in asymptomatically infected or minimally affected flocks, but these viruses are unlikely to cause significant human disease.
Collapse
Affiliation(s)
- Anna R Spickler
- Center for Food Security and Public Health, College of Veterinary Medicine, Iowa State University, Ames, IA 50010, USA
| | | | | |
Collapse
|
60
|
Pavlova SP, Veits J, Keil GM, Mettenleiter TC, Fuchs W. Protection of chickens against H5N1 highly pathogenic avian influenza virus infection by live vaccination with infectious laryngotracheitis virus recombinants expressing H5 hemagglutinin and N1 neuraminidase. Vaccine 2008; 27:773-85. [PMID: 19041677 DOI: 10.1016/j.vaccine.2008.11.033] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 10/20/2008] [Accepted: 11/03/2008] [Indexed: 11/18/2022]
Abstract
Attenuated vaccine strains of the alphaherpesvirus causing infectious laryngotracheitis of chickens (ILTV, gallid herpesvirus 1) can be used for mass application. Previously, we showed that live virus vaccination with recombinant ILTV expressing hemagglutinin of highly pathogenic avian influenza viruses (HPAIV) protected chickens against ILT and fowl plague caused by HPAIV carrying the corresponding hemagglutinin subtypes [Lüschow D, Werner O, Mettenleiter TC, Fuchs W. Protection of chickens from lethal avian influenza A virus infection by live-virus vaccination with infectious laryngotracheitis virus recombinants expressing the hemagglutinin (H5) gene. Vaccine 2001;19(30):4249-59; Veits J, Lüschow D, Kindermann K, Werner O, Teifke JP, Mettenleiter TC, et al. Deletion of the non-essential UL0 gene of infectious laryngotracheitis (ILT) virus leads to attenuation in chickens, and UL0 mutants expressing influenza virus haemagglutinin (H7) protect against ILT and fowl plague. J Gen Virol 2003;84(12):3343-52]. However, protection against H5N1 HPAIV was not satisfactory. Therefore, a newly designed dUTPase-negative ILTV vector was used for rapid insertion of the H5-hemagglutinin, or N1-neuraminidase genes of a recent H5N1 HPAIV isolate. Compared to our previous constructs, protein expression was considerably enhanced by insertion of synthetic introns downstream of the human cytomegalovirus immediate-early promoter within the 5'-nontranslated region of the transgenes. Deletion of the viral dUTPase gene did not affect in vitro replication of the ILTV recombinants, but led to sufficient attenuation in vivo. After a single ocular immunization, all chickens developed H5- or N1-specific serum antibodies. Nevertheless, animals immunized with N1-ILTV died after subsequent H5N1 HPAIV challenge, although survival times were prolonged compared to non-vaccinated controls. In contrast, all chickens vaccinated with either H5-ILTV alone, or H5- and N1-ILTV simultaneously, survived without showing any clinical signs. Real-time RT-PCR indicated limited challenge virus replication after vaccination with H5-ILTV only, which was completely blocked after coimmunization with N1-ILTV. Thus, chickens can be protected from H5N1 HPAIV-induced disease by live vaccination with an attenuated hemagglutinin-expressing ILTV recombinant, and efficacy can be further increased by coadministration of an ILTV mutant expressing neuraminidase. Furthermore, chickens vaccinated with ILTV vectors can be easily differentiated from influenza virus-infected animals by the absence of serum antibodies against the AIV nucleoprotein.
Collapse
Affiliation(s)
- Sophia P Pavlova
- Institute of Molecular Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | | | | | | | | |
Collapse
|
61
|
Zhang S, Xiao L, Zhou H, Yu Z, Chen H, Guo A, Jin M. Generation and characterization of an H5N1 avian influenza virus hemagglutinin glycoprotein pseudotyped lentivirus. J Virol Methods 2008; 154:99-103. [PMID: 18812190 DOI: 10.1016/j.jviromet.2008.08.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 08/20/2008] [Accepted: 08/21/2008] [Indexed: 11/17/2022]
Abstract
An H5N1 avian influenza virus (AIV) hemagglutinin (HA) protein pseudotyped lentivirus, HIV/H5-HA, was generated, characterized in vitro and evaluated for its ability to induce protective immunity against virulent wild type AIV in mice. The HIV/H5-HA virus was able to infect 293T, BHK, Vero, PK-15, MDCK cells but not IBRS-2 cells and therefore demonstrated cell tropism similar to the wild type AIV. HIV/H5-HA agglutinated chicken erythrocytes and cell entry was blocked by ammonium chloride, indicating that the process is pH-dependent. In mice, HIV/H5-HA immunization resulted in low levels of virus in the lungs, elicited high levels of AIV HA-specific antibody as indicated by the hemagglutination inhibition (HI) test, and the antibody induction was both earlier and with a higher titer than that induced by the inactivated AIV vaccine. These results confirmed the roles played by HA in AIV infection and immunogenicity and suggested that the pseudotyped lentivirus is a good model for studying the functions of AIV HA.
Collapse
Affiliation(s)
- Songlin Zhang
- Unit of Animal Infectious Diseases, National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | | | | | | | | | | | | |
Collapse
|
62
|
Heldens JGM, Patel JR, Chanter N, Ten Thij GJ, Gravendijck M, Schijns VEJC, Langen A, Schetters TPM. Veterinary vaccine development from an industrial perspective. Vet J 2008; 178:7-20. [PMID: 18313956 PMCID: PMC7110856 DOI: 10.1016/j.tvjl.2007.11.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 09/26/2007] [Accepted: 11/12/2007] [Indexed: 11/20/2022]
Abstract
Veterinary vaccines currently available in Europe and in other parts of the world are developed by the veterinary pharmaceutical industry. The development of a vaccine for veterinary use is an economic endeavour that takes many years. There are many obstacles along the path to the successful development and launch of a vaccine. The industrial development of a vaccine for veterinary use usually starts after the proof of concept that is based on robust academic research. A vaccine can only be made available to the veterinary community once marketing authorisation has been granted by the veterinary authorities. This review gives a brief description of the regulatory requirements which have to be fulfilled before a vaccine can be admitted to the market. Vaccines have to be produced in a quality controlled environment to guarantee delivery of a product of consistent quality with well defined animal and consumer safety and efficacy characteristics. The regulatory and manufacturing legislative framework in which the development takes place is described, as well as the trend in developments in production systems. Recent developments in bacterial, viral and parasite vaccine research and development are also addressed and the development of novel adjuvants that use the expanding knowledge of immunology and disease pathology are described.
Collapse
Affiliation(s)
- J G M Heldens
- Department for Virological R&D, Nobilon International BV, Exportstraat 39b, 5830 AH Boxmeer, The Netherlands.
| | | | | | | | | | | | | | | |
Collapse
|
63
|
A consensus-hemagglutinin-based DNA vaccine that protects mice against divergent H5N1 influenza viruses. Proc Natl Acad Sci U S A 2008; 105:13538-43. [PMID: 18765801 DOI: 10.1073/pnas.0806901105] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
H5N1 influenza viruses have spread extensively among wild birds and domestic poultry. Cross-species transmission of these viruses to humans has been documented in over 380 cases, with a mortality rate of approximately 60%. There is great concern that a H5N1 virus would acquire the ability to spread efficiently between humans, thereby becoming a pandemic threat. An H5N1 influenza vaccine must, therefore, be an integral part of any pandemic preparedness plan. However, traditional methods of making influenza vaccines have yet to produce a candidate that could induce potently neutralizing antibodies against divergent strains of H5N1 influenza viruses. To address this need, we generated a consensus H5N1 hemagglutinin (HA) sequence based on data available in early 2006. This sequence was then optimized for protein expression before being inserted into a DNA plasmid (pCHA5). Immunizing mice with pCHA5, delivered intramuscularly via electroporation, elicited antibodies that neutralized a panel of virions that have been pseudotyped with the HA from various H5N1 viruses (clades 1, 2.1, 2.2, 2.3.2, and 2.3.4). Moreover, immunization with pCHA5 in mice conferred complete (clades 1 and 2.2) or significant (clade 2.1) protection from H5N1 virus challenges. We conclude that this vaccine, based on a consensus HA, could induce broad protection against divergent H5N1 influenza viruses and thus warrants further study.
Collapse
|
64
|
Avian influenza vaccines: a practical review in relation to their application in the field with a focus on the Asian experience. Epidemiol Infect 2008; 137:1-21. [PMID: 18700992 DOI: 10.1017/s0950268808001039] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Vaccination can be a useful tool for the control of avian influenza (AI) outbreaks, but its use is prohibited in most of the countries worldwide because of its interference with AI surveillance tests and its negative impact on poultry trade. AI vaccines currently in use in the field increase host resistance to the disease but have a limited impact on the virus transmission. To control or eradicate the disease, a carefully conceived vaccination strategy must be accompanied by strict biosecurity measures. Some countries have authorized vaccination under special circumstances with contradictory results, from control and disease eradication (Italy) to endemicity and antigenic drift of the viral strain (Mexico). Extensive vaccination programmes are ongoing in South East Asia to control the H5N1 epidemic. This review provides practical information on the available AI vaccines and associated diagnostic tests, the vaccination strategies applied in Asia and their impact on the disease epidemiology.
Collapse
|
65
|
Potency of an inactivated avian influenza vaccine prepared from a non-pathogenic H5N1 reassortant virus generated between isolates from migratory ducks in Asia. Arch Virol 2008; 153:1685-92. [PMID: 18651092 DOI: 10.1007/s00705-008-0171-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 06/20/2008] [Indexed: 10/21/2022]
Abstract
A reassortant influenza virus, A/duck/Hokkaido/Vac-1/2004 (H5N1) (Dk/Vac-1/04), was generated between non-pathogenic avian influenza viruses isolated from migratory ducks in Asia. Dk/Vac-1/04 (H5N1) virus particles propagated in embryonated chicken eggs were inactivated with formalin and adjuvanted with mineral oil to form a water-in-oil emulsion. The resulting vaccine was injected intramuscularly into chickens. The chickens were challenged with either of the highly pathogenic avian influenza virus strains A/chicken/Yamaguchi/7/2004 (H5N1) or A/swan/Mongolia/3/2005 (H5N1) at 21 days post-vaccination (p. v.), when the geometric mean serum HI titers of the birds was 64 with the challenge virus strains. The vaccinated chickens were protected from manifestation of disease signs upon challenge with either of the highly pathogenic avian influenza viruses. However, challenge virus was recovered at low titers from the birds at 2 and 4 days post-challenge (p.c.). All 3 chickens challenged at 6 days p.v. died, whereas 3 chickens challenged at 8 days p.v. survived. These results indicate that the present vaccine confers clinical protection and reduction of virus shedding against highly pathogenic avian influenza virus challenge and should be useful as an optional tool in emergency cases.
Collapse
|
66
|
Furger M, Hoop R, Steinmetz H, Eulenberger U, Hatt JM. Humoral immune response to avian influenza vaccination over a six-month period in different species of captive wild birds. Avian Dis 2008; 52:222-8. [PMID: 18646450 DOI: 10.1637/8111-091707-reg.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In December 2005, the four major Swiss zoos carried out the vaccination of selected zoo birds with the adjuvant inactivated vaccine H5N2 Nobilis influenza. Pre- and post-vaccination antibody titers were determined either by hemagglutination inhibition (HI) test (non-Galliformes) or by enzyme linked immunosorbent assay (ELISA) (Galliformes) at Week 0, 5, 10, and 26 (Day 0-1, 35-36, 70-71, and 182 respectively) to determine the humoral immune response to H5 antigen. After the first vaccination, the overall geometric mean titer of non-Galliformes was 65 (n = 142), which increased to 187 (n = 139) after booster vaccination and dropped to 74 (n = 65) six months after first vaccination. For the Galliformes group, the mean titers were found to be 2.09 at Week 5 (n = 119), 3.24 at Week 10 (n = 113), and 1.20 at Week 26 (n = 39). Within the non-Galliformes, significant differences in geometric mean titers were found among different species representatives. In general, the flamingos (Phoenicopteriformes) showed a strong response to vaccination, reaching a geometric mean titer of 659 at Week 10, while the Sphenisciformes did not show high antibody titers even after booster vaccination, reaching a maximum geometric mean titer of only 65. Based on the antibody titer profiles of all investigated species, we recommend at least annual revaccination for the species that we investigated.
Collapse
Affiliation(s)
- Maria Furger
- Clinic of Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
| | | | | | | | | |
Collapse
|
67
|
Breiman RF, Nasidi A, Katz MA, Kariuki Njenga M, Vertefeuille J. Preparedness for highly pathogenic avian influenza pandemic in Africa. Emerg Infect Dis 2008; 13:1453-8. [PMID: 18257986 PMCID: PMC2851538 DOI: 10.3201/eid1310.070400] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Africa’s strategies for pandemic influenza must also strengthen overall public health capacity. Global concerns about an impending influenza pandemic escalated when highly pathogenic influenza A subtype H5N1 appeared in Nigeria in January 2006. The potential devastation from emergence of a pandemic strain in Africa has led to a sudden shift of public health focus to pandemic preparedness. Preparedness and control activities must work within the already strained capacity of health infrastructure in Africa to respond to immense existing public health problems. Massive attention and resources directed toward influenza could distort priorities and damage critical public health programs. Responses to concerns about pandemic influenza should strengthen human and veterinary surveillance and laboratory capacity to help address a variety of health threats. Experiences in Asia should provide bases for reassessing strategies for Africa and elsewhere. Fowl depopulation strategies will need to be adapted for Africa. Additionally, the role of avian vaccines should be comprehensively evaluated and clearly defined.
Collapse
|
68
|
Animal health and welfare aspects of avian influenza and the risk of its introduction into the EU poultry holdings - Scientific opinion of the Panel on Animal Health and Welfare. EFSA J 2008. [DOI: 10.2903/j.efsa.2008.715] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
69
|
van den Berg T, Lambrecht B, Marché S, Steensels M, Van Borm S, Bublot M. Influenza vaccines and vaccination strategies in birds. Comp Immunol Microbiol Infect Dis 2008; 31:121-65. [PMID: 17889937 DOI: 10.1016/j.cimid.2007.07.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2007] [Indexed: 12/21/2022]
Abstract
Although it is well accepted that the present Asian H5N1 panzootic is predominantly an animal health problem, the human health implications and the risk of human pandemic have highlighted the need for more information and collaboration in the field of veterinary and human health. H5 and H7 avian influenza (AI) viruses have the unique property of becoming highly pathogenic (HPAI) during circulation in poultry. Therefore, the final objective of poultry vaccination against AI must be eradication of the virus and the disease. Actually, important differences exist in the control of avian and human influenza viruses. Firstly, unlike human vaccines that must be adapted to the circulating strain to provide adequate protection, avian influenza vaccination provides broader protection against HPAI viruses. Secondly, although clinical protection is the primary goal of human vaccines, poultry vaccination must also stop transmission to achieve efficient control of the disease. This paper addresses these differences by reviewing the current and future influenza vaccines and vaccination strategies in birds.
Collapse
Affiliation(s)
- Thierry van den Berg
- Avian Virology & Immunology, Veterinary & Agrochemical Research Centre, 99 Groeselenberg, 1180 Brussels, Belgium.
| | | | | | | | | | | |
Collapse
|
70
|
Goetz S, Spackman E, Hayhow C, Swayne D. Assessment of Reduced Vaccine Dose on Efficacy of an Inactivated Avian Influenza Vaccine Against an H5N1 High-Pathogenicity Avian Influenza Virus. J APPL POULTRY RES 2008. [DOI: 10.3382/japr.2007-00098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
71
|
Protective efficacy of several vaccines against highly pathogenic H5N1 avian influenza virus under experimental conditions. Vaccine 2008; 26:1688-96. [PMID: 18291561 DOI: 10.1016/j.vaccine.2008.01.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Revised: 01/09/2008] [Accepted: 01/11/2008] [Indexed: 12/15/2022]
Abstract
Although several vaccines have been developed to protect against highly pathogenic avian influenza of subtype H5N1 'Asia' their efficiency has primarily been assessed individually. Thus, a direct comparison of their performance is still lacking. The following study was conducted to compare the protective efficacy of three commercially available inactivated vaccines based on influenza virus strains of subtypes H5N2 (vaccine A), H5N9 (vaccine B), and H5N3 (vaccine C), as well as two hemagglutinin expressing experimental vector vaccines (modified vaccinia virus Ankara-H5 and Newcastle disease virus-H5) against a lethal dose of highly pathogenic H5N1 avian influenza virus in chickens. To assess their potential as emergency vaccines, a single immunisation was performed for all vaccines, despite the recommendation of a double-vaccination schedule for commercial vaccines B and C. Overall, all vaccines induced clinical protection against challenge infection 3 weeks after immunisation. No mortality was observed in chickens immunised with vaccine A and viral shedding could not be detected. Immunisation with NDV-H5, vaccine C and MVA-H5 conferred also protection against lethal challenge. However, viral RNA was detected by real-time RT-PCR in swabs of 10%, 20% and 50% of animals, and 0%, 10% and 30% of animals, respectively, shed infectious virus. Immunisation with vaccine B was less protective since 50% of the vaccinated animals shed infectious virus after challenge and 20% of the chickens succumbed to disease. These results indicate that the NDV-H5 vectored vaccine is similarly effective as the best inactivated vaccine. Considering the advantage of live NDV which can be administered via spray or drinking water as well as the potential use of this H5 expressing vector vaccine for an easy DIVA (differentiating infected from vaccinated animals) strategy, NDV-H5 could represent an alternative for extensive vaccination against avian influenza in chickens.
Collapse
|
72
|
Tiensin T, Nielen M, Vernooij H, Songserm T, Kalpravidh W, Chotiprasatintara S, Chaisingh A, Wongkasemjit S, Chanachai K, Thanapongtham W, Srisuvan T, Stegeman A. Transmission of the highly pathogenic avian influenza virus H5N1 within flocks during the 2004 epidemic in Thailand. J Infect Dis 2007; 196:1679-84. [PMID: 18008253 DOI: 10.1086/522007] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Accepted: 02/09/2007] [Indexed: 11/03/2022] Open
Abstract
This present study is the first to quantify the transmission of avian influenza virus H5N1 within flocks during the 2004 epidemic in Thailand. It uses the flock-level mortality data to estimate the transmission-rate parameter ( beta ) and the basic reproduction number (R(0)). The point estimates of beta varied from 2.26/day (95% confidence interval [CI], 2.01-2.55) for a 1-day infectious period to 0.66/day (95% CI, 0.50-0.87) for a 4-day infectious period, whereas the accompanying R(0) varied from 2.26 (95% CI, 2.01-2.55) to 2.64 (95% CI, 2.02-3.47). Although the point estimates of beta of backyard chickens and fighting cocks raised together were lower than those of laying hens and broiler chickens, this difference was not statistically significant. These results will enable us to assess the control measures in simulation studies. They also indicate that, for the elimination of the virus, a critical proportion of the susceptible poultry population in a flock (i.e., 80% of the population) needs to be vaccinated.
Collapse
Affiliation(s)
- Thanawat Tiensin
- Department of Livestock Development, Ministry of Agriculture and Cooperatives, Bangkok, Thailand.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
73
|
Swayne DE, Avellaneda G, Mickle TR, Pritchard N, Cruz J, Bublot M. Improvements to the Hemagglutination Inhibition Test for Serological Assessment of Recombinant Fowlpox–H5-Avian-Influenza Vaccination in Chickens and Its Use Along with an Agar Gel Immunodiffusion Test for Differentiating Infected from Noninfected Vaccinated Animals. Avian Dis 2007; 51:697-704. [DOI: 10.1637/0005-2086(2007)51[697:itthit]2.0.co;2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
74
|
Spackman E, Swayne DE, Suarez DL, Senne DA, Pedersen JC, Killian ML, Pasick J, Handel K, Pillai SPS, Lee CW, Stallknecht D, Slemons R, Ip HS, Deliberto T. Characterization of low-pathogenicity H5N1 avian influenza viruses from North America. J Virol 2007; 81:11612-9. [PMID: 17728231 PMCID: PMC2168782 DOI: 10.1128/jvi.01368-07] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 10(5.3) and 10(7.5) 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage.
Collapse
Affiliation(s)
- Erica Spackman
- Southeast Poultry Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, 934 College Station Road, Athens, GA 30605, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
75
|
Beato MS, Toffan A, De Nardi R, Cristalli A, Terregino C, Cattoli G, Capua I. A conventional, inactivated oil emulsion vaccine suppresses shedding and prevents viral meat colonisation in commercial (Pekin) ducks challenged with HPAI H5N1. Vaccine 2007; 25:4064-72. [PMID: 17420074 DOI: 10.1016/j.vaccine.2007.02.042] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 02/05/2007] [Accepted: 02/08/2007] [Indexed: 11/20/2022]
Abstract
The ongoing H5N1 epidemic is currently affecting a number of avian species, including waterfowl. These birds appear to have an important role as reservoirs of infection and comprehensive data on the efficacy of vaccination is currently lacking. The present paper reports the effect of a two dose vaccination programme with a conventional inactivated product on infection, lateral spread, shedding and presence of virus in commodities such as meat and viscera of Pekin ducks. Vaccination of this species appears to be efficacious in suppressing viral shedding, and preventing viraemia and lateral spread of infection to unvaccinated and vaccinated Pekin ducks.
Collapse
Affiliation(s)
- Maria Serena Beato
- Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Padua, Italy
| | | | | | | | | | | | | |
Collapse
|
76
|
Bublot M, Le Gros FX, Nieddu D, Pritchard N, Mickle TR, Swayne DE. Efficacy of Two H5N9-Inactivated Vaccines Against Challenge with a Recent H5N1 Highly Pathogenic Avian Influenza Isolate from a Chicken in Thailand. Avian Dis 2007; 51:332-7. [PMID: 17494577 DOI: 10.1637/7623-042706r.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The objective of this study was to compare the efficacy of two avian influenza (AI) H5-inactivated vaccines containing either an American (A/turkey/Wisconsin/68 H5N9; H5N9-WI) or a Eurasian isolate (A/chicken/Italy/22A/98 H5N9; H5N9-It). Three-week-old specific pathogen-free chickens were vaccinated once and challenged 3 wk later with a H5N1 highly pathogenic AI (HPAI) virus isolated from a chicken in Thailand in 2004. All unvaccinated challenged birds died within 2 days, whereas 90% and 100% of chickens vaccinated with H5N9-WI and H5N9-It, respectively, were protected against morbidity and mortality. Both vaccines prevented cloacal shedding and significantly reduced oral shedding of the challenge HPAI virus. Additional chickens (vaccinated or unvaccinated) were placed in contact with the directly challenged birds 18 hr after challenge. All unvaccinated chickens in contact with unvaccinated challenged birds died within 3 days after contact, whereas unvaccinated chickens in contact with vaccinated challenged birds either showed a significantly delayed mortality or did not become infected. All vaccinated contacts were protected against clinical signs, and most chickens did not shed detectable amount of HPAI virus. Altogether, these data indicate that both vaccines protected very well against morbidity and mortality and reduced or prevented shedding induced by direct or contact exposure to Asian H5N1 HPAI virus.
Collapse
|
77
|
Terregino C, Toffan A, Beato MS, De Nardi R, Drago A, Capua I. Conventional H5N9 Vaccine Suppresses Shedding in Specific-Pathogen-Free Birds Challenged with HPAI H5N1 A/Chicken/Yamaguchi/7/2004. Avian Dis 2007; 51:495-7. [PMID: 17494617 DOI: 10.1637/7565-033106r.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Avian influenza represents one of the greatest concerns for public health that has emerged in recent times. Highly pathogenic avian influenza viruses belonging to the H5N1 subtype are endemic in Asia and are spreading in Europe and Africa. Vaccination is now considered a tool to support eradication efforts, provided it is appropriately managed. This study was carried out to establish the degree of clinical protection and reduction of viral shedding induced by a high-specification, commercially available avian influenza vaccine of a different lineage and containing a strain with a heterologous neuraminidase (H5N9 subtype) to the challenge virus isolate A/chicken/Yamaguchi/7/2004 (H5N1 subtype).
Collapse
Affiliation(s)
- C Terregino
- OIE, FAO and National Reference Laboratory for Avian Influenza and Newcastle Disease, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'università 10, Legnaro, 35020, Padova, Italy
| | | | | | | | | | | |
Collapse
|
78
|
Philippa J, Baas C, Beyer W, Bestebroer T, Fouchier R, Smith D, Schaftenaar W, Osterhaus A. Vaccination against highly pathogenic avian influenza H5N1 virus in zoos using an adjuvanted inactivated H5N2 vaccine. Vaccine 2007; 25:3800-8. [PMID: 17403559 DOI: 10.1016/j.vaccine.2007.01.121] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 01/23/2007] [Accepted: 01/30/2007] [Indexed: 11/19/2022]
Abstract
Highly pathogenic avian influenza (HPAI) H5N1 virus infections have recently caused unprecedented morbidity and mortality in a wide range of avian species. European Commission directive 2005/744/EC allowed vaccination in zoos under strict conditions, while reducing confinement measures. Vaccination with a commercial H5N2 vaccine with vaccine doses adapted to mean body weight per species was safe, and proved immunogenic throughout the range of species tested, with some variations between and within taxonomic orders. After booster vaccination the overall homologous geometric mean titre (GMT) to the vaccine strain, measured in 334 birds, was 190 (95% CI: 152-236), and 80.5% of vaccinated birds developed a titre of >or=40. Titres to the HPAI H5N1 virus followed a similar trend, but were lower (GMT: 61 (95% CI: 49-76); 61%>or=40). The breadth of the immune response was further demonstrated by measuring antibody titres against prototype strains of four antigenic clades of currently circulating H5N1 viruses. These data indicate that vaccination should be regarded as a beneficial component of the preventive measures (including increased bio-security and monitoring) that can be undertaken in zoos to prevent an outbreak of and decrease environmental contamination by HPAI H5N1 virus, while alleviating confinement measures.
Collapse
MESH Headings
- Adjuvants, Immunologic
- Animals
- Animals, Zoo
- Antibodies, Viral/blood
- Birds/classification
- Influenza A Virus, H5N1 Subtype/pathogenicity
- Influenza A Virus, H5N2 Subtype/genetics
- Influenza A Virus, H5N2 Subtype/immunology
- Influenza Vaccines/administration & dosage
- Influenza Vaccines/adverse effects
- Influenza Vaccines/immunology
- Influenza Vaccines/therapeutic use
- Influenza in Birds/immunology
- Influenza in Birds/prevention & control
- Influenza in Birds/virology
- Vaccination/veterinary
- Vaccines, Inactivated/administration & dosage
- Vaccines, Inactivated/adverse effects
- Vaccines, Inactivated/immunology
- Vaccines, Inactivated/therapeutic use
Collapse
Affiliation(s)
- Joost Philippa
- Institute of Virology, Erasmus MC, P.O. Box 2040, 3000 CA, Rotterdam, The Netherlands.
| | | | | | | | | | | | | | | |
Collapse
|
79
|
Ma HC, Chen JM, Chen JW, Sun YX, Li JM, Wang ZL. The panorama of the diversity of H5 subtype influenza viruses. Virus Genes 2006; 34:283-7. [PMID: 16924425 DOI: 10.1007/s11262-006-0018-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Accepted: 05/10/2006] [Indexed: 10/24/2022]
Abstract
To elucidate the global diversity of H5 influenza viruses from a dynamic view, haemagglutinin (HA) sequences of 170 isolates were selected and analyzed in this study. Our results showed that H5 influenza isolates could be divided into two distinct lineages that circulated in the Eastern Hemisphere and the Western Hemisphere, respectively. This may be due to the separate migration routes and habitats of birds in the two hemispheres. The two distinct lineages, having existed at least for decades, possibly began divergence in 1850s. Each of the two distinct HA lineages could be further divided into some sublineages, but there was little correlation between the minor lineages and their isolation places, isolation time, neuraminidase subtypes, host species or virulence. The panorama of the diversity of H5 influenza viruses presented here integrated all known H5 epidemics including the current severe H5N1 avian epidemics in the Eastern Hemisphere and suggested that H5 virulent viruses could originate from multiple sublineages and associate with multiple NA subtypes. Our study provided a framework for the studies on the evolution and epidemiology of H5 influenza viruses.
Collapse
Affiliation(s)
- Hong-Chao Ma
- Chinese Center for Animal Health and Epidemiology, Nanjing Road 369#, Qingdao 266032, China
| | | | | | | | | | | |
Collapse
|