scholarly journals Discordant Correlation between Serological Assays Observed When Measuring Heterosubtypic Responses against Avian Influenza H5 and H7 Viruses in Unexposed Individuals

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Eleonora Molesti ◽  
Francesca Ferrara ◽  
Giulia Lapini ◽  
Emanuele Montomoli ◽  
Nigel Temperton
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Vaccine Development ◽  
Critical Role ◽  
Haemagglutination Inhibition ◽  
Influenza Surveillance ◽  
Complex Nature ◽  
Italian Population ◽  
Influenza A Viruses ◽  
Serum Samples

The human population is constantly exposed to multiple influenza A subtypes due to zoonotic spillover and rapid viral evolution driven by intrinsic error-prone replication and immunological pressure. In this context, antibody responses directed against the HA protein are of importance since they have been shown to correlate with protective immunity. Serological techniques, detecting these responses, play a critical role for influenza surveillance, vaccine development, and assessment. As the recent human pandemics and avian influenza outbreaks have demonstrated, there is an urgent need to be better prepared to assess the contribution of the antibody response to protection against newly emerged viruses and to evaluate the extent of preexisting heterosubtypic immunity in populations. In this study, 68 serum samples collected from the Italian population between 1992 and 2007 were found to be positive for antibodies against H5N1 as determined by single radial hemolysis (SRH), but most were negative when evaluated using haemagglutination inhibition (HI) and microneutralisation (MN) assays. As a result of these discordant serological findings, the increased sensitivity of lentiviral pseudotypes was exploited in pseudotype-based neutralisation (pp-NT) assays and the results obtained provide further insight into the complex nature of humoral immunity against influenza A viruses.

scholarly journals Avian Influenza A Virus Pandemic Preparedness and Vaccine Development

Vaccines ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 46 ◽  
Author(s):  
Rory de Vries ◽  
Sander Herfst ◽  
Mathilde Richard
Keyword(s):  
Avian Influenza ◽  
Influenza A Virus ◽  
Influenza A ◽  
Vaccine Development ◽  
Influenza Pandemic ◽  
Broad Host Range ◽  
Influenza A Viruses ◽  
Vaccination Strategies ◽  
Pandemic Virus ◽  
Wide Range

Influenza A viruses can infect a wide range of hosts, creating opportunities for zoonotic transmission, i.e., transmission from animals to humans, and placing the human population at constant risk of potential pandemics. In the last hundred years, four influenza A virus pandemics have had a devastating effect, especially the 1918 influenza pandemic that took the lives of at least 40 million people. There is a constant risk that currently circulating avian influenza A viruses (e.g., H5N1, H7N9) will cause a new pandemic. Vaccines are the cornerstone in preparing for and combating potential pandemics. Despite exceptional advances in the design and development of (pre-)pandemic vaccines, there are still serious challenges to overcome, mainly caused by intrinsic characteristics of influenza A viruses: Rapid evolution and a broad host range combined with maintenance in animal reservoirs, making it near impossible to predict the nature and source of the next pandemic virus. Here, recent advances in the development of vaccination strategies to prepare against a pandemic virus coming from the avian reservoir will be discussed. Furthermore, remaining challenges will be addressed, setting the agenda for future research in the development of new vaccination strategies against potentially pandemic influenza A viruses.

Serosurveillance study on transmission of H5N1 virus during a 2006 avian influenza epidemic

2010 ◽  
Vol 138 (9) ◽  
pp. 1274-1280 ◽  
Author(s):  
M. CEYHAN ◽  
I. YILDIRIM ◽  
O. FERRARIS ◽  
M. BOUSCAMBERT-DUCHAMP ◽  
E. FROBERT ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Neutralizing Antibodies ◽  
Healthcare Workers ◽  
Influenza A ◽  
Haemagglutination Inhibition ◽  
Subclinical Infection ◽  
Serum Samples ◽  
Polymerase Chain ◽  
Paired Serum ◽  
Human Infections

SUMMARYIn 2006 an outbreak of avian influenza A(H5N1) in Turkey caused 12 human infections, including four deaths. We conducted a serological survey to determine the extent of subclinical infection caused by the outbreak. Single serum samples were collected from five individuals with avian influenza whose nasopharyngeal swabs tested positive for H5 RNA by polymerase chain reaction, 28 family contacts of the cases, 95 poultry cullers, 75 individuals known to have had contact with diseased chickens and 81 individuals living in the region with no known contact with infected chickens and/or patients. Paired serum samples were collected from 97 healthcare workers. All sera were tested for the presence of neutralizing antibodies by enzyme-linked immunoassay, haemagglutination inhibition and microneutralization assays. Only one serum sample, from a parent of an avian influenza patient, tested positive for H5N1 by microneutralization assay. This survey shows that there was minimal subclinical H5N1 infection among contacts of human cases and infected poultry in Turkey in 2006. Further, the low rate of subclinical infection following contact with diseased poultry gave further support to the reported low infectivity of the virus.

scholarly journals Avian Influenza Surveillance in the Danube Delta Using Sentinel Geese and Ducks

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Alexandru Coman ◽  
Daniel Narcis Maftei ◽  
Razvan M. Chereches ◽  
Elena Zavrotchi ◽  
Paul Bria ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Danube Delta ◽  
Influenza A Viruses ◽  
Highly Pathogenic ◽  
Domestic Bird ◽  
Hpai H5n1 ◽  
Migrating Birds

Highly pathogenic avian influenza (HPAI) H5N1 virus incursions from migrating birds have occurred multiple times in Romania since 2005. Beginning in September 2008 through April 2013, seasonal sentinel surveillance for avian influenza A viruses (AIVs) using domestic geese (Anser cygnoides) and ducks (Anas platyrhynchos) in the Danube Delta was established by placing 15 geese and 5 ducks at seven sites. Tracheal and cloacal swabs, and sera collections (starting in 2009) were taken monthly. We studied a total of 580 domestic birds and collected 5,520 cloacal and tracheal swabs from each and 2,760 sera samples. All swabs were studied with real-time reverse transcription polymerase chain reaction (rRT-PCR) for evidence of AIV. Serological samples were studied with hemagglutination inhibition assays against avian H5, H7, and H9 influenza viruses. From 2009 to 2013, 47 swab specimens from Cot Candura, Enisala, and Saon screened positive for AIV; further subtyping demonstrated that 14 ducks and 20 geese had cloacal evidence of H5N3 carriage. Correspondingly, 4 to 12 weeks after these molecular detections, sentinel bird sera revealed elevated HI titers against H5 virus antigens. We posit that domestic bird surveillance is an effective method to conduct AIV surveillance among migrating birds in delta areas.

scholarly journals Antibody against influenza A2 virus neuraminidase in human sera

1969 ◽  
Vol 67 (2) ◽  
pp. 353-365 ◽  
Author(s):  
G. C. Schild ◽  
R. W. Newman
Keyword(s):  
Influenza A ◽  
Complement Fixation ◽  
Haemagglutination Inhibition ◽  
Vaccine Trial ◽  
Research Centre ◽  
Influenza A Viruses ◽  
Serum Samples ◽  
The Public ◽  
Human Sera ◽  
Serial Serum

SUMMARY1. High titres of neuraminidase-inhibiting antibody were detected in convalescent human sera following natural influenza A2 infections.2. Such antibody was encountered infrequently in acute serum samples. Antibody persisted only 5–6 months after infection in the four individuals from whom serial serum specimens were available.3. Following immunization with killed influenza virus vaccines (with adjuvant) neuraminidase inhibiting antibody was detected in human sera. The titres were in general lower than those detected in convalescent human sera.4. The specificity of the neuraminidase-inhibiting antibody in human and animal antisera was studied. Tests with convalescent human sera using purified neuraminidase preparations and with a recombinant virus containing A2 neuraminidase and haemagglutinin distinct from that of human influenza A viruses enabled the conclusion that the antibody detected was specific for influenza A 2 neuraminidase.We wish to thank Dr D. A. J. Tyrrell of the Clinical Research Centre, Mill Hill, London, for human serum specimens, Dr D. Breeze of Evans Medical Ltd., Liverpool, for sera from an influenza vaccine trial and Dr M. S. Pereira of the Public Health Laboratory, Colindale, London, for serial serum samples from persons who had influenza in 1957. Dr M. S. Pereira carried out the haemagglutination-inhibition tests and complement fixation tests on these sera.We are grateful to Dr H. G. Pereira and Dr D. A. J. Tyrrell for valuable discussions during the course of this study, and to Professor C. H. Stuart-Harris for his comments on the manuscript.

scholarly journals Unique structural solution from a VH3-30 antibody targeting the hemagglutinin stem of influenza A viruses

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wayne D. Harshbarger ◽  
Derrick Deming ◽  
Gordon J. Lockbaum ◽  
Nattapol Attatippaholkun ◽  
Maliwan Kamkaew ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Influenza A ◽  
Critical Role ◽  
Binding Activity ◽  
Human Antibody ◽  
Broadly Neutralizing Antibodies ◽  
Influenza A Viruses ◽  
Universal Vaccine ◽  
Structural Details ◽  
Structural Solution

AbstractBroadly neutralizing antibodies (bnAbs) targeting conserved influenza A virus (IAV) hemagglutinin (HA) epitopes can provide valuable information for accelerating universal vaccine designs. Here, we report structural details for heterosubtypic recognition of HA from circulating and emerging IAVs by the human antibody 3I14. Somatic hypermutations play a critical role in shaping the HCDR3, which alone and uniquely among VH3-30 derived antibodies, forms contacts with five sub-pockets within the HA-stem hydrophobic groove. 3I14 light-chain interactions are also key for binding HA and contribute a large buried surface area spanning two HA protomers. Comparison of 3I14 to bnAbs from several defined classes provide insights to the bias selection of VH3-30 antibodies and reveals that 3I14 represents a novel structural solution within the VH3-30 repertoire. The structures reported here improve our understanding of cross-group heterosubtypic binding activity, providing the basis for advancing immunogen designs aimed at eliciting a broadly protective response to IAV.

scholarly journals Development and application of a real-time RT-PCR assay to rapidly detect H2 subtype avian influenza A viruses

2021 ◽  
pp. 104063872199481
Author(s):  
Yixin Xiao ◽  
Fan Yang ◽  
Fumin Liu ◽  
Hangping Yao ◽  
Nanping Wu ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Real Time ◽  
Influenza A ◽  
Minor Groove Binder ◽  
Rt Pcr ◽  
Influenza A Viruses ◽  
Pcr Assay ◽  
Infectious Dose ◽  
The Matrix ◽  
Taqman Minor Groove Binder

The H2 subtypes of avian influenza A viruses (avian IAVs) have been circulating in poultry, and they have the potential to infect humans. Therefore, establishing a method to quickly detect this subtype is pivotal. We developed a TaqMan minor groove binder real-time RT-PCR assay that involved probes and primers based on conserved sequences of the matrix and hemagglutinin genes. The detection limit of this assay was as low as one 50% egg infectious dose (EID50)/mL per reaction. This assay is specific, sensitive, and rapid for detecting avian IAV H2 subtypes.

scholarly journals Protection of Mice and Poultry from Lethal H5N1 Avian Influenza Virus through Adenovirus-Based Immunization

2006 ◽  
Vol 80 (4) ◽  
pp. 1959-1964 ◽  
Author(s):  
Wentao Gao ◽  
Adam C. Soloff ◽  
Xiuhua Lu ◽  
Angela Montecalvo ◽  
Doan C. Nguyen ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Influenza A ◽  
Recombinant Adenovirus ◽  
Critical Role ◽  
H5n1 Avian Influenza Virus ◽  
Recent Emergence ◽  
Boost Vaccine ◽  
Subcutaneous Immunization

ABSTRACT The recent emergence of highly pathogenic avian influenza virus (HPAI) strains in poultry and their subsequent transmission to humans in Southeast Asia have raised concerns about the potential pandemic spread of lethal disease. In this paper we describe the development and testing of an adenovirus-based influenza A virus vaccine directed against the hemagglutinin (HA) protein of the A/Vietnam/1203/2004 (H5N1) (VN/1203/04) strain isolated during the lethal human outbreak in Vietnam from 2003 to 2005. We expressed different portions of HA from a recombinant replication-incompetent adenoviral vector, achieving vaccine production within 36 days of acquiring the virus sequence. BALB/c mice were immunized with a prime-boost vaccine and exposed to a lethal intranasal dose of VN/1203/04 H5N1 virus 70 days later. Vaccination induced both HA-specific antibodies and cellular immunity likely to provide heterotypic immunity. Mice vaccinated with full-length HA were fully protected from challenge with VN/1203/04. We next evaluated the efficacy of adenovirus-based vaccination in domestic chickens, given the critical role of fowl species in the spread of HPAI worldwide. A single subcutaneous immunization completely protected chickens from an intranasal challenge 21 days later with VN/1203/04, which proved lethal to all control-vaccinated chickens within 2 days. These data indicate that the rapid production and subsequent administration of recombinant adenovirus-based vaccines to both birds and high-risk individuals in the face of an outbreak may serve to control the pandemic spread of lethal avian influenza.

Ongoing transmission of avian influenza A viruses in Hong Kong despite very comprehensive poultry control measures: A prospective seroepidemiology study

2016 ◽  
Vol 72 (2) ◽  
pp. 207-213 ◽  
Author(s):  
Kelvin K.W. To ◽  
Ivan F.N. Hung ◽  
Yin-Ming Lui ◽  
Florence K.Y. Mok ◽  
Andy S.F. Chan ◽  
...  
Keyword(s):  
Hong Kong ◽  
Avian Influenza ◽  
Influenza A ◽  
Control Measures ◽  
Influenza A Viruses

scholarly journals Isolation and characterization of low pathogenic H9N2 avian influenza A viruses from a healthy flock and its comparison to other H9N2 isolates

2013 ◽  
Vol 24 (3) ◽  
pp. 342-348 ◽  
Author(s):  
Muhammad Munir ◽  
Siamak Zohari ◽  
Muhammad Abbas ◽  
Muhammad Zubair Shabbir ◽  
Muhammad Nauman Zahid ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Influenza A Viruses ◽  
Isolation And Characterization

scholarly journals Characterization of a Human H5N1 Influenza A Virus Isolated in 2003

2005 ◽  
Vol 79 (15) ◽  
pp. 9926-9932 ◽  
Author(s):  
Kyoko Shinya ◽  
Masato Hatta ◽  
Shinya Yamada ◽  
Ayato Takada ◽  
Shinji Watanabe ◽  
...  
Keyword(s):  
Hong Kong ◽  
Avian Influenza ◽  
Influenza A Virus ◽  
Influenza A ◽  
Mainland China ◽  
Virus Infections ◽  
Influenza A Viruses ◽  
H5n1 Avian Influenza Virus ◽  
H5n1 Influenza ◽  
Avian Influenza A Virus

ABSTRACT In 2003, H5N1 avian influenza virus infections were diagnosed in two Hong Kong residents who had visited the Fujian province in mainland China, affording us the opportunity to characterize one of the viral isolates, A/Hong Kong/213/03 (HK213; H5N1). In contrast to H5N1 viruses isolated from humans during the 1997 outbreak in Hong Kong, HK213 retained several features of aquatic bird viruses, including the lack of a deletion in the neuraminidase stalk and the absence of additional oligosaccharide chains at the globular head of the hemagglutinin molecule. It demonstrated weak pathogenicity in mice and ferrets but caused lethal infection in chickens. The original isolate failed to produce disease in ducks but became more pathogenic after five passages. Taken together, these findings portray the HK213 isolate as an aquatic avian influenza A virus without the molecular changes associated with the replication of H5N1 avian viruses in land-based poultry such as chickens. This case challenges the view that adaptation to land-based poultry is a prerequisite for the replication of aquatic avian influenza A viruses in humans.

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