MedWorm: H2N2

Protective efficacy of an H1N1 cold-adapted live vaccine against the 2009 pandemic H1N1, seasonal H1N1, and H5N1 influenza viruses in mice.

Antiviral Research — Wed, 18 Jan 2012 05:00:00 +0100

Authors: Shi J, Wen Z, Guo J, Zhang Y, Deng G, Shu Y, Wang D, Jiang Y, Kawaoka Y, Bu Z, Chen H Abstract Vaccination is a key strategy for preventing influenza virus infections. Here, we generated a reassortant virus (SC/AAca) containing the hemagglutinin and neuraminidase genes from a 2009 pandemic influenza virus A/Sichuan/1/2009 (H1N1) (SC/09) and six internal genes from the cold-adapted virus A/Ann Arbor/6/60 (H2N2) (AAca). The SC/AAca reassortant induced a sound humoral immune response and complete protection against homologous SC/09 virus challenge in mice after intranasal administration of an at least 10(6) 50% egg infectious dose (EID(50)) of SC/AAca. SC/AAca inoculation also induced significant CD4+ and CD8+ T cell responses and provided solid protection against heterologou...

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Mimotopes selected with neutralizing antibodies against Multiple Subtypes of Influenza A

Virology Journal — Thu, 15 Dec 2011 05:00:00 +0100

Conclusions: Phage-displayed mimotopes against multiple subtypes of influenza A were accessible to the mouse immune system and triggered a humoral response to above virus. (Source: Virology Journal)

Genetic evolution of low pathogenecity H9N2 Avian influenza viruses in Tunisia: Acquisition of new mutations

Virology Journal — Wed, 12 Oct 2011 04:00:00 +0100

Conclusion: Considering these mutations, the molecular basis of tropism, host responses and enhanced virulence will be defined and studied. Otherwise, Continuous monitoring of viral genetic changes throughout the year is warranted to monitor variations of Influenza viruses in the field. (Source: Virology Journal)

Memory T-Cell Immune Response in Healthy Young Adults Vaccinated with Live Attenuated Influenza A (H5N2) Vaccine.

Clinical and Vaccine Immunology — Sat, 01 Oct 2011 04:00:00 +0100

Authors: Chirkova TV, Naykhin AN, Petukhova GD, Korenkov DA, Donina SA, Mironov AN, Rudenko LG Abstract Cellular immune responses of both CD4 and CD8 memory/effector T cells were evaluated in healthy young adults who received two doses of live attenuated influenza A (H5N2) vaccine. The vaccine was developed by reassortment of nonpathogenic avian A/Duck/Potsdam/1402-6/68 (H5N2) and cold-adapted A/Leningrad/134/17/57 (H2N2) viruses. T-cell responses were measured by standard methods of intracellular cytokine staining of gamma interferon (IFN-γ)-producing cells and a novel T-cell recognition of antigen-presenting cells by protein capture (TRAP) assay based on the trogocytosis phenomenon, namely, plasma membrane exchange between interacting immune cells. TRAP enables the detection of ...

Comparative safety, immunogenicity, and efficacy of several anti‐H5N1 influenza experimental vaccines in a mouse and chicken models (Testing of killed and live H5 vaccine)

Influenza and Other Respiratory Viruses — Thu, 01 Sep 2011 04:00:00 +0100

Conclusions The high yield, safety, and protectivity of VN‐Len and Ku‐Len made them promising strains for the production of inactivated and live vaccines against H5N1 viruses. (Source: Influenza and Other Respiratory Viruses)

Memory T-cell immune response in healthy young adults vaccinated with live attenuated influenza A(H5N2) vaccine.

Clinical and Vaccine Immunology — Tue, 02 Aug 2011 23:00:00 +0100

Authors: Chirkova TV, Naykhin AN, Petukhova GD, Korenkov DA, Donina SA, Mironov AN, Rudenko LG Cellular immune responses of both CD4 and CD8 memory/effector T cells were evaluated in healthy young adults who received two doses of live attenuated influenza A(H5N2) vaccine. The vaccine was developed by reassortment of non-pathogenic avian A/Duck/Potsdam/1402-6/68 (H5N2) and cold-adapted A/Leningrad/134/17/57 (H2N2) viruses. T-cell responses were measured by standard methods of intracellular cytokine staining of IFNγ-producing cells and a novel TRAP-assay based on the trogocytosis phenomenon - plasma membrane exchange between interacting immune cells. TRAP (T-cell Recognition of Antigen-Presenting Cells by Protein Capture) enables the detection of activated trogocytosis-positive T-cells ...

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Pandemic influenza in Africa, lessons learned from 1968: a systematic review of the literature

Influenza and Other Respiratory Viruses — Sat, 30 Apr 2011 23:00:00 +0100

Conclusion The 1968 H3N2 influenza pandemic, generally regarded as mild worldwide, appears to have had a substantial impact upon public health in Africa. Without more epidemiologic data the impact of the 2009 H1N1 pandemic in Africa cannot be assumed to have been mild. Assessment of the burden of 2009 H1N1 virus and future influenza pandemics in Africa should attempt to assess disease impact by a variety of methods, including substudies among specific populations. (Source: Influenza and Other Respiratory Viruses)

A nanobeads amplified QCM immunosensor for the detection of avian influenza virus H5N1.

Biosensors and Bioelectronics — Tue, 12 Apr 2011 23:00:00 +0100

In this study, magnetic nanobeads amplification based quartz crystal microbalance (QCM) immunosensor was developed as a new method and application for AI H5N1 virus detection. Polyclonal antibodies against AI H5N1 virus surface antigen HA (Hemagglutinin) were immobilized on the gold surface of the QCM crystal through self-assembled monolayer (SAM) of 16-mercaptohexadecanoic acid (MHDA). Target H5N1 viruses were then captured by the immobilized antibodies, resulting in a change in the frequency. Magnetic nanobeads (diameter, 30nm) coated with anti-H5 antibodies were used for further amplification of the binding reaction between antibody and antigen (virus). Both bindings of target H5N1 viruses and magnetic nanobeads onto the crystal surface were further confirmed by environmental scanning e...

Study urges H2N2 vaccination drive

Nursing Times Breaking News — Fri, 11 Mar 2011 09:18:00 +0100

An H2N2 flu vaccination programme should be carried out by governments in a bid to protect against any future pandemic, a report has claimed. (Source: Nursing Times Breaking News)

NHS Choices assessment of press reports warning about future flu strains

NeLM - News — Fri, 11 Mar 2011 00:00:00 +0100

Source: NHS Choices Area: News NHS Choices has conducted an assessment of a report in The Independent that "Governments should start vaccinations against a lethal strain of the influenza virus circulating in birds and pigs." The news is based on a report by researchers working at the Vaccine Research Centre of the US National Institutes of Health and published in the journal Nature. The report notes that an old flu strain known as H2N2, which caused a pandemic in the 1950s and 60s, could easily start circulating again in humans. The researchers also conducted a small test of 90 people, which showed that people under the age of 50 have little or no immunity to the strain. They argue that creating a new vaccination programme to deal with this strain of flu could save lives by pre...

Scientists warn about future flu strains

NHS News Feed — Thu, 10 Mar 2011 17:20:00 +0100

Conclusion The researchers raise important questions about the possibility of a future flu pandemic caused by the H2N2 virus, and about whether vaccination programme planning could be used to prevent it. However, many issues need further consideration, including a detailed assessment of the probability of the H2N2 strain jumping to humans, whether it would pose a serious health threat, how long it would take to emerge and which groups of people would be vulnerable. It is important to note that infection with the H1N1 virus, although dangerous for some population groups, did not make most people seriously ill. As the researchers point out, there are concerns over whether it makes sense to expose individuals to vaccines for a virus that is not currently circulating in humans, although they s...

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Call to vaccinate against new flu

BBC News | Health | UK Edition — Wed, 09 Mar 2011 18:00:04 +0100

Governments should launch a vaccination programme now to guard against a possible H2N2 flu pandemic, according to an article in the journal Nature. (Source: BBC News | Health | UK Edition)

Vaccinate for the next H2N2 pandemic now

Nature — Wed, 09 Mar 2011 00:00:00 +0100

Authors: Gary J. Nabel, Chih-Jen Wei & Julie E. Ledgerwood An old influenza strain still circulating in birds and swine could easily jump back to humans now that immunity to it has dropped, warn Gary J. Nabel and his colleagues. (Source: Nature)

Genetic bases of the temperature-sensitive phenotype of a master donor virus used in live attenuated influenza vaccines: A/Leningrad/134/17/57 (H2N2).

Virology — Wed, 09 Feb 2011 00:00:00 +0100

Authors: Isakova-Sivak I, Chen LM, Matsuoka Y, Voeten JT, Kiseleva I, Heldens JG, den Bosch HV, Klimov A, Rudenko L, Cox NJ, Donis RO Trivalent live attenuated influenza vaccines whose type A components are based on cold-adapted A/Leningrad/134/17/57 (H2N2) (caLen17) master donor virus (MDV) have been successfully used in Russia for decades to control influenza. The vaccine virus comprises hemagglutinin and neuraminidase genes from the circulating viruses and the remaining six genes from the MDV. The latter confer temperature-sensitive (ts) and attenuated (att) phenotypes. The ts phenotype of the vaccine virus is a critical biological determinant of attenuation of virulence. We developed a plasmid-based reverse genetics system for MDV caLen17 to study the genetic basis of its ts phenot...

Upstream start codon in segment 4 of North American H2 avian influenza A viruses.

Infection, Genetics and Evolution — Tue, 11 Jan 2011 00:00:00 +0100

Authors: Girard G, Gultyaev AP, Olsthoorn RC H2N2 influenza A virus was the cause of the 1957 pandemic. Due to its constant presence in birds, the H2 subtype remains a topic of interest. In this work, comparison of H2 leader sequences of influenza A segment 4 revealed the presence of an upstream in-frame start codon in a majority of North American avian strains. This AUG is located seven codons upstream of the conventional start codon and is in a good Kozak context. In vivo experiments, using a luciferase reporter gene fused to leader sequences derived from North American avian H2 strains, support the efficient use of the upstream start codon. These results were corroborated by in vitro translation data using full-length segment 4 mRNA. Phylogenic analyses indicate that the upstream AU...

Severe pandemic 2009 H1N1 influenza disease due to pathogenic immune complexes

Nature Medicine — Sun, 05 Dec 2010 00:00:00 +0100

Authors: Ana Clara Monsalvo, Juan P Batalle, M Florencia Lopez, Jens C Krause, Jennifer Klemenc, Johanna Zea Hernandez, Bernardo Maskin, Jimena Bugna, Carlos Rubinstein, Leandro Aguilar, Liliana Dalurzo, Romina Libster, Vilma Savy, Elsa Baumeister, Liliana Aguilar, Graciela Cabral, Julia Font, Liliana Solari, Kevin P Weller, Joyce Johnson, Marcela Echavarria, Kathryn M Edwards, James D Chappell, James E Crowe, John V Williams, Guillermina A Melendi & Fernando P Polack Pandemic influenza viruses often cause severe disease in middle-aged adults without preexisting comorbidities. The mechanism of illness associated with severe disease in this age group is not well understood. Here we find preexisting serum antibodies that cross-react with, but do not protect against, 2009 H1N1 influenza v...

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Immunogenicity and protective efficacy of a live attenuated vaccine against the 2009 pandemic A H1N1 in Mice and Ferrets.

Vaccine — Wed, 24 Nov 2010 00:00:00 +0100

In this study, using reverse genetic technology, we produced a cold-adapted (ca), live attenuated BJ/AA ca that contained hemagglutinin (HA) and neuraminidase (NA) genes from a 2009 pandemic A H1N1 isolate, A/Beijing/501/2009 virus (BJ501), and the remaining six internal gene segments from the cold-adapted influenza H2N2 A/Ann Arbor/6/60 virus (AA virus). BJ/AA ca exhibited phenotypes of temperature sensitivity (ts), ca, and attenuation (att). The candidate BJ/AA ca was immunogenic in mice and induced strong mucosal secretory IgA (sIgA) in the respiratory tract. Two dosages of intranasal immunization induced robust HI antibodies and offered efficient protection against challenge by the wild-type (wt) 2009 pandemic A H1N1 (A/Beijing/501/2009 or A/California/07/2009) in mice and ferrets. The...

Origin of the 1918 pandemic H1N1 influenza A virus as studied by codon usage patterns and phylogenetic analysis.

RNA — Wed, 10 Nov 2010 00:00:00 +0100

Authors: Anhlan D, Grundmann N, Makalowski W, Ludwig S, Scholtissek C The pandemic of 1918 was caused by an H1N1 influenza A virus, which is a negative strand RNA virus; however, little is known about the nature of its direct ancestral strains. Here we applied a broad genetic and phylogenetic analysis of a wide range of influenza virus genes, in particular the PB1 gene, to gain information about the phylogenetic relatedness of the 1918 H1N1 virus. We compared the RNA genome of the 1918 strain to many other influenza strains of different origin by several means, including relative synonymous codon usage (RSCU), effective number of codons (ENC), and phylogenetic relationship. We found that the PB1 gene of the 1918 pandemic virus had ENC values similar to the H1N1 classical swine and huma...

Influenza A virus strains that circulate in humans differ in the ability of their NS1 proteins to block the activation of IRF3 and interferon-β transcription.

Virology — Wed, 06 Oct 2010 23:00:00 +0100

Authors: Kuo RL, Zhao C, Malur M, Krug RM We demonstrate that influenza A virus strains that circulate in humans differ markedly in the ability of their NS1 proteins to block the activation of IRF3 and interferon-β transcription. Strong activation occurs in cells infected with viruses expressing NS1 proteins of seasonal H3N2 and H2N2 viruses, whereas activation is blocked in cells infected with viruses expressing NS1 proteins of some, but not all seasonal H1N1 viruses. The NS1 proteins of the 2009 H1N1 and H5N1 viruses also block these activations. The difference in this NS1 function is mediated largely by the C-terminal region of the effector domain, which contains the only amino acid (K or E at position 196) that covaries with the functional difference. Further, we show that TRIM25 ...

Hunt for universal flu vaccine

NHS News Feed — Fri, 16 Jul 2010 10:23:00 +0100

Conclusion This is complex and valuable scientific research. It found that H1N1 and H3N2 plasmid vaccines in combination with the seasonal booster gave protection against numerous H1N1 and H3N2 strains. When the H1N1 plasmid was combined with the adenovirus 5 booster, protection was given against other viral strains as well (H5N1 and H2N2 strains). The research is in the early stages and has so far been carried out only in animal models. The newsreports of a vaccine that protects against ‘every strain’ are premature. The current experiments have not tested whether the vaccine can produce effective antibodies against every strain of influenza virus that has ever circulated. As influenza vaccines are constantly changing, the effects on these newer strains also cannot be predicted. Howeve...

Master donor viruses A/Leningrad/134/17/57 (H2N2) and B/USSR/60/69 and derived reassortants used in live attenuated influenza vaccine (LAIV) do not display neurovirulent properties in a mouse model

Archives of Virology — Wed, 09 Jun 2010 09:02:05 +0100

Abstract Demonstration of the absence of neurovirulent properties of reassortant viruses contained in live attenuated influenza vaccine (LAIV) is a regulatory requirement. A mouse model was used to detect neurovirulent properties of the cold-adapted, temperature-sensitive and attenuated influenza master donor viruses (MDVs) A/Leningrad/134/17/57 (H2N2) and B/USSR/60/69 and derived reassortant influenza viruses. A/NWS/33 (H1N1), which is known to be neurovirulent in mice, was used as a positive control. Under conditions where the positive control virus induced symptoms of disease and showed viral replication in the upper respiratory tract as well as in the brain, replication of the influenza master donor viruses and reassortant influenza A and B viruses was limited to the u...

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In vitro antiviral activity of favipiravir (T-705) against drug-resistant influenza and 2009 A(H1N1) viruses.

Antimicrobial Agents and Chemotherapy — Sun, 28 Mar 2010 23:00:00 +0100

This study demonstrates that favipiravir inhibits in vitro replication of a wide range of influenza viruses, including those resistant to currently available drugs. PMID: 20350949 [PubMed - as supplied by publisher] (Source: Antimicrobial Agents and Chemotherapy)

H1N1 Influenza Pandemics: Comparing the Events of 2009 in Mexico with those of 1976 and 1918–1919

Archives of Medical Research — Thu, 07 Jan 2010 00:00:00 +0100

Outbreaks of influenza A (H1N1) of avian- or swine-related origin have substantially impacted human populations. The most dramatic pandemic of influenza H1N1 occurred during 1918–1919 producing significant morbidity and mortality worldwide. In the 20th century, two other major pandemics took place but they were the H2N2 and H3N2 reassorted influenza strains. In 1976, a small outbreak of swine-related H1N1 in the U.S. led to a national scare but without any significant public health impact. More recently, in April 2009, in Mexico, and subsequently worldwide, an influenza (H1N1) triple reassortant strain produced >200,000 laboratory-confirmed cases and resulted in >2000 deaths. In August 2009, WHO declared this outbreak as the first influenza pandemic of the 21st century. It is critical to...

Safety, immunogencity, and efficacy of a cold-adapted A/Ann Arbor/6/60 (H2N2) vaccine in mice and ferrets.

Virology — Tue, 22 Dec 2009 00:00:00 +0100

Authors: Chen GL, Lamirande EW, Jin H, Kemble G, Subbarao K We studied the attenuation, immunogenicity and efficacy of the cold-adapted A/Ann Arbor/6/60 (AA ca) (H2N2) virus in mice and ferrets to evaluate its use in the event of an H2 influenza pandemic. The AA ca virus was restricted in replication in the respiratory tract of mice and ferrets. In mice, 2 doses of vaccine elicited a >4-fold rise in hemagglutination-inhibition (HAI) titer and resulted in complete inhibition of viral replication following lethal homologous wild-type virus challenge. In ferrets, a single dose of the vaccine elicited a >4-fold rise in HAI titer and conferred complete protection against homologous wild-type virus challenge in the upper respiratory tract. In both mice and ferrets, the AA ca virus prov...

Seasonal, Avian, and Novel H1N1 Influenza: Prevention and Treatment Modalities (December).

The Annals of Pharmacotherapy — Tue, 17 Nov 2009 00:00:00 +0100

CONCLUSIONS: Influenza subtypes continue to change, causing disease in animals and humans. Utilization of immunization and antiviral treatment options are available to prevent, treat, and contain the spread of this infection. PMID: 19920156 [PubMed - as supplied by publisher] (Source: The Annals of Pharmacotherapy)

New WHO Criteria To Qualify Flu Viruses As Pandemic Strains

Health News from Medical News Today — Wed, 04 Nov 2009 08:00:00 +0100

An editorial published today in BMJ Clinical Evidence reports that more flu viruses could qualify as pandemic strains as a result of recent changes to the World Health Organisation (WHO) criteria for a flu pandemic. A change from, for example, A [H2N2] influenza to A [H3N2] is a process known as a "shift". (Source: Health News from Medical News Today)

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The influence of the multi-basic cleavage site of the H5 hemagglutinin on the attenuation, immunogenicity and efficacy of a live attenuated influenza A H5N1 cold-adapted vaccine virus.

Virology — Mon, 12 Oct 2009 23:00:00 +0100

Authors: Suguitan AL, Marino MP, Desai PD, Chen LM, Matsuoka Y, Donis RO, Jin H, Swayne DE, Kemble G, Subbarao K A recombinant live attenuated influenza virus DeltaH5N1 vaccine with a modified hemagglutinin (HA) and intact neuraminidase genes from A/Vietnam/1203/04 (H5N1) and six remaining genome segments from A/Ann Arbor/6/60 (H2N2) cold-adapted (AA ca) virus was previously shown to be attenuated in chickens, mice and ferrets. Evaluation of the recombinant H5N1 viruses in mice indicated that three independent factors contributed to the attenuation of the DeltaH5N1 vaccine: the attenuating mutations specified by the AA ca loci had the greatest influence, followed by the deletion of the H5 HA multi-basic cleavage site (MBS), and the constellation effects of the AA genes acting in concer...

Residual immunity in older people against the influenza A(H1N1) - recent experience in northern Spain

Eurosurveillance latest news — Thu, 01 Oct 2009 00:00:00 +0100

The 2009 pandemic influenza A(H1N1) virus has a higher incidence in children and young adults, a pattern that has also been reported in seasonal influenza caused by the influenza A(H1N1) virus. We analysed age at infection in symptomatic patients with influenza in the Basque Country (northern Spain), reported through the sentinel influenza surveillance system which monitors 2.2-2.5% of the population. Between September 1999 and August 2009, influenza A(H3N2) or seasonal influenza A(H1N1) was detected in 941 patients, and from April to August 2009, pandemic influenza A(H1N1) was detected in 112 patients. The H3/H1 seasonal influenza ratio was between 3.3 and 3.4 in the under 60 year-olds, but 9.8 in older individuals, suggesting that people born before 1950 have residual immunity against th...

Molecular Detection of a Novel Human Influenza (H1N1) of Pandemic Potential by Conventional and Real-Time Quantitative RT-PCR Assays [Brief Communications]

Clinical Chemistry — Mon, 27 Jul 2009 23:00:00 +0100

Conclusions: These assays appear useful for the rapid diagnosis of cases with the novel H1N1 virus, thereby allowing better pandemic preparedness. (Source: Clinical Chemistry)

H1N1 traced to 1918 pandemic

NHS News Feed — Tue, 21 Jul 2009 16:47:00 +0100

The history of swine flu

NHS News Feed — Tue, 30 Jun 2009 18:30:00 +0100

The Independent says that “the swine flu pandemic might not have happened had it not been for the accidental release of the same strain of influenza virus from a research laboratory in the late 1970s.” The news comes from a medical article which analysed the history of the influenza A H1N1 virus, including the recent development of swine flu seen around the world. The reports say that the H1N1 influenza strain was responsible for a flu pandemic in 1977, but before this it had not been found in humans for more than 20 years. By looking at the genetic makeup of the 1977 virus, researchers have found that it was similar to a strain that was circulating in 1950. This 1950s strain would have been stored in labs and researchers have suggested that the re-emergence of the virus in 1977 “was...

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Extant blood samples to deduce the strains of the 1890 and possibly earlier pandemic influenzas

Medical Hypotheses — Sun, 24 May 2009 23:00:00 +0100

Summary: Influenza outbreaks in 1918, 1957 and 1968 caused some of the highest infectious disease mortality in the 20th century. In particular the 1918 pandemic caused more than 50 million deaths worldwide—the most deaths caused by any infectious disease ever in human history. Influenza pandemics in 1890 and earlier in the 19th century and back until at least the 16th century also caused non-trivial mortality. The excessively high mortality from flu in these years is thought to be due to major antigenic shifts in influenza strains, as opposed to smaller drifts in flu strains in years between pandemics. It is also thought that flu strains cycle naturally; however, as the 1918 pandemic was caused by an H1N1 strain, the 1957 pandemic by an H2N2 strain and the 1968 pandemic by an H3N2 flu, t...

Functional significance of the hemadsorption activity of influenza virus neuraminidase and its alteration in pandemic viruses

Archives of Virology — Thu, 21 May 2009 06:21:03 +0100

Abstract Human influenza viruses derive their genes from avian viruses. The neuraminidase (NA) of the avian viruses has, in addition to the catalytic site, a separate sialic acid binding site (hemadsorption site) that is not present in human viruses. The biological significance of the NA hemadsorption activity in avian influenza viruses remained elusive. A sequence database analysis revealed that the NAs of the majority of human H2N2 viruses isolated during the influenza pandemic of 1957 differ from their putative avian precursor by amino acid substitutions in the hemadsorption site. We found that the NA of a representative pandemic virus A/Singapore/1/57 (H2N2) lacks hemadsorption activity and that a single reversion to the avian-virus-like sequence (N367S) restores hemad...

Characteristics of arbidol-resistant mutants of influenza virus: Implications for the mechanism of anti-influenza action of arbidol.

Antiviral Research — Fri, 21 Nov 2008 05:00:00 +0100

Authors: Leneva IA, Russell RJ, Boriskin YS, Hay AJ The antiviral drug arbidol (ARB), which is licensed in Russia for use against influenza, is known to inhibit early membrane fusion events in influenza A and B virus replication. To investigate in more detail the target and mechanism of ARB action we generated and studied the characteristics of ARB-resistant influenza virus mutants. Observations of the ARB susceptibility of reassortants between A/Singapore/1/57(H2N2) and A/chicken/Germany/27(H7N7, "Weybridge" strain) and of mutants of the latter virus identified the virus haemagglutinin (HA) as the major determinant of ARB sensitivity. ARB-resistant mutants, selected from the most sensitive reassortant, possessed single amino acid substitutions in the HA2 subunit which caused an increa...

Genetic characterization and protective immunity of cold-adapted attenuated avian H9N2 influenza vaccine.

Vaccine — Fri, 03 Oct 2008 04:00:00 +0100

Authors: Lee JS, Kim HS, Seo SH H9N2 influenza viruses are endemic in many Asian countries including China and Korea, and cause a considerable economic loss to chicken industry by reduction in egg production and about 30% mortality. Here we developed live cold-adapted attenuated H9N2 influenza vaccine by adaptation of viruses in hen's eggs at 25 degrees C. Genetic analysis shows that the cold-adapted H9N2 (A/Chicken/Korea/S1/03) viruses contain a total of 44 amino acid substitutions, of which 7 amino acids are identical to the loci identified in the cold-adapted H2N2 (A/Ann Arbor/6/60) vaccine strain compared to genes in wild-type H9N2 (A/Chicken/Korea/S1/03) influenza viruses. When cold-adapted H9N2 (A/Chicken/Korea/S1/03) influenza viruses were inoculated in layers viruses were detec...

Prevalence of avian influenza viruses, Borrelia garinii, Mycobacterium avium, and Mycobacterium avium subsp. paratuberculosis in waterfowl and terrestrial birds in Slovakia, 2006.

Avian Pathology — Thu, 18 Sep 2008 17:52:35 +0100

Authors: Gronesova P, Ficova M, Mizakova A, Kabat P, Trnka A, Betakova T The prevalence of Borrelia, Mycobacteria and avian influenza virus (AIV) infections, together with the distribution of different AIV subtypes, was studied in migratory waterfowl and terrestrial birds trapped in three localities in Slovakia during 2006. Samples obtained from waterfowl captured in the Senianske Ponds area of Eastern Slovakia showed the highest diversity of AIV isolates. A total of 13 different subtypes were detected in 19 samples from this location (H1N2, H2N2, H3N2, H6N6, H7N6, H9N2, H9N5, H9N6, H10N5, H10N6, H12N6, H13N6, and H16N6). H3N5 virus was detected in 50% of passerines testing positive for AIV in the Parizske Wetlands, with H7N2, H9N2, H9N5, H12N1, and H13N2 infections also recorded at th...

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Homologous recombination evidence in human and swine influenza A viruses.

Virology — Wed, 20 Aug 2008 04:00:00 +0100

This study reports several significant evidence demonstrating that homologous recombination also takes place between influenza A viruses in human and swine lineages. Moreover, in a mosaic descended from swine H1N1 subtype and human H2N2, we found that its minor putative parent might be a derivative from the human cold-adapted vaccine lineage, which suggests that live vaccine is capable of playing a role in genetic change of influenza A virus via recombination with circulating viruses. These results would be important for knowing the molecular mechanism of mammal influenza A virus heredity and evolution. PMID: 18721995 [PubMed - as supplied by publisher] (Source: Virology)

Effects of single-point amino acid substitutions on the structure and function neuraminidase proteins in influenza A virus.

Microbiology and Immunology — Thu, 03 Jul 2008 15:39:44 +0100

Authors: Yano T, Nobusawa E, Nagy A, Nakajima S, Nakajima K In order to clarify the effect of amino acid substitutions on the structure and function of the neuraminidase (NA) protein of influenza A virus, we introduced single-point amino acid substitutions into the NA protein of the A/Tokyo/3/67 (H2N2) strain using PCR-based random mutation. The rate of tolerant random one amino acid substitutions in the NA protein was 47%. Rates of tolerant substitutions for the stalk and for the surface and inner portion of the head region of the NA protein were 79, 54, and 19%, respectively. Deleterious changes, such as those causing the NA protein to stop at the Golgi/endoplasmic reticulum, were scattered throughout the protein. On the other hand, the ratio of mutations with which the NA protein lo...

Confronting an influenza pandemic with inexpensive generic agents: can it be done?

The Lancet Infectious Diseases — Tue, 15 Apr 2008 04:00:00 +0100

Authors: Fedson DS Avian influenza A H5N1 presents a serious and possibly imminent pandemic threat. In such an event, adequate supplies of affordable vaccines and antiviral agents will be unavailable to most people in the world. In view of the overwhelming need for effective alternatives, generic agents that target the host immune response or the pandemic virus should be considered. Many scientists doubt the effectiveness of these agents. Nonetheless, several studies suggest that statins improve outcomes in patients with bacteraemia and pneumonia and might be similarly effective against influenza. An experimental study has shown that the fibrate gemfibrozil, a peroxisome proliferator-activated receptor (PPAR) alpha agonist, reduces mortality in H2N2 influenza virus-infected mice. There...

An exploratory method for estimating the changing speed of epidemic waves from historical data

International Journal of Epidemiology — Thu, 31 Jan 2008 05:00:00 +0100

Conclusions The new measure of wave velocity appears to be applicable to those historical time series where breakdown into regional or local areas is available. The study is being extended to (i) other countries where similar influenza time series are available and (ii) to other diseases within Iceland. (Source: International Journal of Epidemiology)

Healthy Human Subjects Have CD4+ T Cells Directed against H5N1 Influenza Virus.

Journal of Immunology — Thu, 24 Jan 2008 10:28:50 +0100

Authors: Roti M, Yang J, Berger D, Huston L, James EA, Kwok WW It is commonly perceived that the human immune system is naive to the newly emerged H5N1 virus. In contrast, most adults have been exposed to influenza A H1N1 and H3N2 viruses through vaccination or infection. Adults born before 1968 have likely been exposed to H2N2 viruses. We hypothesized that CD4(+) T cells generated in response to H1N1, H3N2, and H2N2 influenza A viruses also recognize H5N1 epitopes. Tetramer-guided epitope mapping and Ag-specific class II tetramers were used to identify H5N1-specific T cell epitopes and detect H5N1-specific T cell responses. Fifteen of 15 healthy subjects tested had robust CD4(+) T cell responses against matrix protein, nucleoprotein, and neuraminidase of the influenza A/Viet Nam/1203/...

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Automated extraction of avian influenza virus for rapid detection using real-time RT-PCR.

Journal of Clinical Virology — Sat, 15 Sep 2007 04:00:00 +0100

CONCLUSION: The main advantages of automated robotic viral nucleic acid extraction are high throughput processing; hands-free operation; and reduction in human and technical error. This study demonstrates successful detection of influenza A virus with magnetic beads utilizing the Qiagen MagAttract cell kit on a BioRobot M48 platform. PMID: 17875401 [PubMed - as supplied by publisher] (Source: Journal of Clinical Virology)

Non-compact nucleocapsid protein multimers in influenza-virus-infected cells

Archives of Virology — Wed, 10 Jan 2007 07:54:23 +0100

In this study we demonstrate that, in addition to compact NP oligomers, incompletely folded NP multimers are detected in tracellularly by SDS/PAGE carried out under weak dissociating conditions. In cells infected with avian, human A(H2N2), and human A(H3N2) viruses, NP multimers are detected in the stacking gel of SDS/PAGE as retarded and loose structures dissociating at +50??C. NP multimers are more sensitive to proteolysis than NP oligomers, but they are more resistant to proteolysis than NP monomers. In contrast to compact NP oligomers, NP multimers possess a weak immunoreactivity to some monoclonal antibodies. Pulse-chase experiments have shown that NP multimers appear at early stages of NP synthesis and are partially converted post-translationally into faster-migrating compact NP olig...

Laboratory Exposure to Influenza A H2N2, Germany, 2004–2005, A. Schrauder et al.

Emerging Infectious Diseases Journal — Wed, 15 Nov 2006 10:58:02 +0100

(Source: Emerging Infectious Diseases Journal)

Characterization of an influenza A H5N2 reassortant as a candidate for live-attenuated and inactivated vaccines against highly pathogenic H5N1 viruses with pandemic potential.

Vaccine — Sat, 21 Oct 2006 08:21:02 +0100

Authors: Desheva JA, Lu XH, Rekstin AR, Rudenko LG, Swayne DE, Cox NJ, Katz JM, Klimov AI We generated a high-growth 7:1 reassortant (Len17/H5) that contained the hemagglutinin (HA) gene from non-pathogenic A/Duck/Potsdam/1402-6/86 (H5N2) virus and other genes from the cold-adapted (ca) attenuated A/Leningrad/134/17/57 (H2H2) strain. Len17/H5 demonstrated an attenuated phenotype in mice and did not infect chickens. Mice administered Len17/H5 either as a live-attenuated intranasal vaccine or as an inactivated intramuscular vaccine were substantially protected from lethal challenge with highly pathogenic A/Hong Kong/483/97 (H5N1) virus and were protected from pulmonary infection with antigenically distinct A/Hong Kong/213/2003 (H5N1) virus. The cross-protective effect correlated with the...

The origins of new pandemic viruses: the acquisition of new host ranges by canine parvovirus and influenza A viruses.

Annual Review of Microbiology — Sat, 01 Jan 2005 05:00:00 +0100

Authors: Parrish CR, Kawaoka Y Transfer of viruses between hosts to create a new self-sustaining epidemic is rare; however, those new viruses can cause severe outbreaks. Examples of such viruses include three pandemic human influenza A viruses and canine parvovirus in dogs. In each case one virus made the original transfer and spread worldwide, and then further adaptation resulted in the emergence of variants worldwide. For the influenza viruses several changes were required for growth and spread between humans, and the emergence of human H2N2 and H3N2 strains in 1957 and 1968 involved the acquisition of three or two new genomic segments, respectively. Adaptation to humans involved several viral genes including the hemagglutinin, the neuraminidase, and the replication proteins. The can...

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