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  • outbreak
  • Because large quantities of monoclonal antibodies can be made relatively quickly, after more testing, these influenza-specific monoclonal antibodies potentially could be used in combination with antiviral drugs to prevent or treat the flu during an influenza outbreak or pandemic. (webwire.com)
  • Here, we describe the characterization of virus isolates obtained from poultry and humans during an outbreak of HPAI that started in February 2003 in The Netherlands and spread subsequently to poultry in Germany and Belgium ( 13 ). (pnas.org)
  • The research team that worked on this report also believed that it was "derived from several viruses circulating in swine," and that the initial transmission to humans occurred several months before recognition of the outbreak. (wikipedia.org)
  • Fears of a similar pandemic have health officials concerned the death toll could be much higher in a modern outbreak, which researchers say is very likely if the current deadly bird flu morphs into a strain that can be transmitted by humans. (nbcnews.com)
  • Although at least 67 human deaths have been reported in the current outbreak, most of these people were in direct contact with infected birds - either during defeathering, slaughtering, or eating uncooked birds. (nbcnews.com)
  • On September 29, 2005, David Nabarro, the newly appointed Senior United Nations System Coordinator for Avian and Human Influenza, warned the world that an outbreak of avian influenza could kill anywhere between 5 million and 150 million people. (wikipedia.org)
  • The February 6, 2004 edition of Science magazine reported that two research teams, one led by Sir John Skehel, director of the National Institute for Medical Research in London, another by Professor Ian Wilson of The Scripps Research Institute in San Diego, had managed to synthesize the hemagglutinin protein responsible for the flu outbreak of 1918. (wikipedia.org)
  • The outbreak in Hong Kong, where density is about 500 people per acre, reached maximum intensity in two weeks, lasting six months in total from July to December 1968, however worldwide deaths from this virus peaked much later, in December 1968 and January 1969. (wikipedia.org)
  • The category 2 Asian flu pandemic outbreak of influenza A virus originated in China in early 1956, and lasted until 1958. (wikipedia.org)
  • Researchers concluded the swine H2N3 virus represents a threat to humans with the potential for causing a larger outbreak in a non-immune or partially immune population. (wikipedia.org)
  • viral
  • Viral CTL epitopes can display variation, allowing influenza A viruses to evade recognition by epitope-specific CTLs. (asm.org)
  • This difference in recognition may have implications for the viral replication kinetics in HLA-A*0201 individuals and spread of influenza A viruses in the human population. (asm.org)
  • Antigenic drifts are causedby frequent mutations during the replication step introduced by the viral polymerase complex: the viruses can be antigenically different and cause epidemics . (pubmedcentralcanada.ca)
  • Viral RNAs (vRNA) were extracted directly from virus-containing allantoic fluid (150 µl) using RNA isolation kit (Macherey Nagel) according to the manufacturer's instructions. (pubmedcentralcanada.ca)
  • Over the years, influenza A viruses have been one of the most important models for studying how the immune system responds to viral infections. (bio-medicine.org)
  • Antigenic shift is important for the emergence of new viral pathogens as it is a pathway that viruses may follow to enter a new niche. (wikipedia.org)
  • In terms of virology, the marine ecosystem has been largely unstudied, but due to its extraordinary volume, high viral density (100 million viruses per mL in coastal waters, 3 million per mL in the deep sea) and high cell lysing rate (as high as 20% on average), marine viruses' antigenic shift and genetic recombination rates must be quite high. (wikipedia.org)
  • Genetic mutations in the hemagglutinin gene that cause single amino acid substitutions can significantly alter the ability of viral hemagglutinin proteins to bind to receptors on the surface of host cells. (wikipedia.org)
  • The PB1 protein is a critical component of the viral polymerase. (wikipedia.org)
  • PB1-F2 likely contributes to viral pathogenicity and might have an important role in determining the severity of pandemic influenza. (wikipedia.org)
  • Although viruses can differ with respect to many phenotypes, phylodynamic studies have to date tended to focus on a limited number of viral phenotypes. (wikipedia.org)
  • The relative lengths of internal versus external branches will be affected by changes in viral population size over time (see figure 1) Rapid expansion of a virus in a population will be reflected by a "star-like" tree, in which external branches are long relative to internal branches. (wikipedia.org)
  • Compared to a phylogeny of an expanding virus, a phylogeny of a viral population that stays constant in size will have external branches that are shorter relative to branches on the interior of the tree. (wikipedia.org)
  • The phylogeny of hepatitis B virus (caricatured by figure 1B) instead reflects a viral population that has remained roughly constant in size. (wikipedia.org)
  • The clustering of taxa on a viral phylogeny will be affected by host population structure (see figure 2) Viruses within similar hosts, such as hosts that reside in the same geographic region, are expected to be more closely related genetically if transmission occurs more commonly between them. (wikipedia.org)
  • Tree balance will be affected by selection, most notably immune escape (see figure 3) The effect of directional selection on the shape of a viral phylogeny is exemplified by contrasting the trees of influenza virus and HIV's surface proteins. (wikipedia.org)
  • vaccines
  • The findings may aid the rational design of universal influenza vaccines that aim at the induction of cross-reactive virus-specific CTL responses. (asm.org)
  • These results provide novel insights into the epidemiology of influenza A viruses and their pathogenicity and may aid rational design of vaccines that aim at the induction of CTL responses. (asm.org)
  • The World health organization (WHO) coordinates influenza surveillance programs and twice a year, reference strains included in vaccines of the North and South hemispheres are sent to manufacturers. (pubmedcentralcanada.ca)
  • This renewed interest could lead to new discoveries of immune system response to viruses that could lead to better drugs and vaccines, the researchers write in a review article that appears in the May issue of Nature Immunology. (bio-medicine.org)
  • Until recently, many immunologists were relatively uninterested in studying influenza immunity because there were already effective vaccines," said Peter Doherty, Ph.D., member of the St. Jude Department of Immunology and co-recipient of the 1996 Nobel Prize for Medicine. (bio-medicine.org)
  • Currently, sporadic cases, but no evident outbreaks, of this novel virus have been documented in wild birds and poultry, and there is some limited evidence of human-to-human transmission during unprotected exposure [ 12 ], and there are no vaccines for humans. (biomedcentral.com)
  • VLP vaccines already approved for use in people include those to protect against hepatitis B and human papillomavirus . (medicalnewstoday.com)
  • Antigenic drift refers to the continuous changes in the virus that make it slightly different than previous versions, requiring the yearly production of new vaccines. (nbcnews.com)
  • At least 12 companies and 17 governments are developing prepandemic influenza vaccines in 28 different clinical trials that, if successful, could turn a deadly pandemic infection into a nondeadly one. (wikipedia.org)
  • Present vaccination strategies for swine influenza virus (SIV) control and prevention in swine farms typically include the use of one of several bivalent SIV vaccines commercially available in the United States. (wikipedia.org)
  • reassortant
  • Postreassortment changes in HA receptor-binding and NA substrate specificities for three reassortant/passage variant virus pairs towards 3′SiaLac, 3′SiaLacNAc, SiaLe c , SiaLe a , SiaLe x , 6′SiaLac, and 6′SiaLacNAc were determined. (springer.com)
  • According to research published by the US National Institutes of Health, the triple reassortant H2N3 virus isolated from diseased pigs in the United States in 2006 is pathogenic for certain mammals without prior adaptation and transmits among swine and ferrets. (wikipedia.org)
  • illness
  • Of these 89 patients, 78 presented with conjunctivitis, 5 presented with conjunctivitis and influenza-like illness, 2 presented with influenza-like illness, and 4 did not fit the case definitions. (pnas.org)
  • Clinical specimens, including throat swabs, sputum or tracheal aspirates, etc., were obtained from patients exhibiting influenza-like illness (ILIs), especially from those having pneumonia and a history of occupational exposure to poultry and wild birds. (biomedcentral.com)
  • The DNA primarily causes the illness, but it's the proteins that determine how well it spreads. (nbcnews.com)
  • Over the years the H9N2 influenza strain caused illness in several children aged nine months to 5 years in Hong Kong with the latest occurring in December 2009. (wikipedia.org)
  • Strain A/cal/Duschanbe/55/71 could be detected for seven days and caused an influenza-like illness in calves. (wikipedia.org)
  • Epidemic
  • The epidemic is the largest since the first epidemic in 2013 and accounts for about one-third of human cases ever reported. (wikipedia.org)
  • ISBN 962-209-805-3 Chapter Two : Avian Influenza by Timm C. Harder and Ortrud Werner from free on-line Book called Influenza Report 2006 which is a medical textbook that provides a comprehensive overview of epidemic and pandemic influenza. (wikipedia.org)
  • Furthermore, surveillance efforts in farmed pig populations need to become an integral part of any epidemic and pandemic influenza preparedness. (wikipedia.org)
  • poultry
  • Infected poultry were thought to be the source of the virus. (medicalxpress.com)
  • The same virus was detected subsequently in 86 humans who handled affected poultry and in three of their family members. (pnas.org)
  • This virus was not previously known to be circulating in poultry or other animals. (who.int)
  • The crucial role of H9N2 viruses due to the wide host range, adaptation to both poultry and mammals and extensive gene reassortment. (wikipedia.org)
  • A risk factor for contracting the virus is handling of infected poultry, but transmission of the virus from infected birds to humans has been characterized as inefficient. (wikipedia.org)
  • It is known that influenza tends to strike during the winter months, and the second wave, which began in October, was fanned by a surge in poultry production timed for Chinese New Year feasts that began at the end of January. (wikipedia.org)
  • pathogenicity
  • Results reported by Webster in July 2005 reveal further progression toward pathogenicity in mice and longer virus shedding by ducks. (wikipedia.org)
  • respiratory
  • IMPORTANCE Influenza viruses are an important cause of acute respiratory tract infections. (asm.org)
  • Influenza viruses are among the leading causes of acute respiratory tract infections worldwide ( 1 ). (asm.org)
  • Abundant virus attachment to the human upper respiratory tract correlates with efficient transmissibility among humans," explains Thijs Kuiken, DVM, PhD, of the Department of Viroscience at Erasmus University Medical Centre in Rotterdam, The Netherlands. (medicalxpress.com)
  • Influenza-like illnesses were generally mild, but a fatal case of pneumonia in combination with acute respiratory distress syndrome occurred also. (pnas.org)
  • It is responsible for binding the virus to cells with sialic acid on the membranes, such as cells in the upper respiratory tract or erythrocytes. (wikipedia.org)
  • Both viruses replicated in the entire respiratory tract, but only swine H2N3 could be isolated from lung tissue on day 6 post infection. (wikipedia.org)
  • antibodies
  • Key to their research, Dr. Marasco and his colleagues discovered and described the atomic structure of an obscure but genetically stable region of the influenza virus to which their monoclonal antibodies bind. (webwire.com)
  • Encouraged by these findings, they collaborated with Ruben O. Donis, Ph.D., of the CDC Influenza Division, and found that three of these monoclonal antibodies had broader neutralization capabilities when tested in cell cultures and in mice against representative strains of other known influenza A viruses. (webwire.com)
  • One of the most remarkable findings of our work is that we identified a highly conserved region in the neck of the influenza hemagglutinin protein to which humans rarely make antibodies, says Dr. Marasco. (webwire.com)
  • We believe this is because the head of the hemagglutinin protein acts as a decoy by constantly undergoing mutation and thereby attracting the immune system to produce antibodies against it rather than against the pocket in the neck of the protein. (webwire.com)
  • Antibodies raised by M2e-tGCN4 immunization specifically bound to the surface of influenza-infected cells and to an M2-expressing cell line. (jove.com)
  • Therefore, fusion of an oligomerization domain to the extracellular part of a transmembrane protein allows it to mimic the natural quaternary structure and can promote the induction of oligomer-specific antibodies. (jove.com)
  • Since hemagglutinin is the major surface protein of the influenza A virus and is essential to the entry process, it is the primary target of neutralizing antibodies. (wikipedia.org)
  • When an organism is exposed to a particular antigen (i.e. a protein on the surface of a bacterium) an immune response is stimulated and antibodies are generated to target that specific antigen. (wikipedia.org)
  • Transmission of the virus from pigs to humans is not common and does not always lead to human flu, often resulting only in the production of antibodies in the blood. (wikipedia.org)
  • pigs
  • Until recently, it was thought that pigs were required as an intermediate host for transmission of AIV to humans ( 5 , 6 ). (pnas.org)
  • On June 23, 2009, The New York Times reported that U.S. federal agriculture officials, "contrary to the popular assumption that the new swine flu pandemic arose on factory farms in Mexico," now believe that it "most likely emerged from pigs in Asia, but then traveled to North America in a human. (wikipedia.org)
  • Oliver Pybus of Oxford University's Department of Zoology, and part of the research team, claims "Our results show that this strain has been circulating among pigs, possibly among multiple continents, for many years prior to its transmission to humans. (wikipedia.org)
  • The new subtypes arose in pigs coinfected with avian and human viruses and were soon transferred to humans. (wikipedia.org)
  • Pigs have often been seen as "mixing vessels", which help to change and evolve strains of disease that are then passed on to other mammals, such as humans. (wikipedia.org)
  • Direct transmission of a swine flu virus from pigs to humans is occasionally possible (zoonotic swine flu). (wikipedia.org)
  • Influenza is quite common in pigs, with about half of breeding pigs having been exposed to the virus in the US. (wikipedia.org)
  • 1957
  • For example, 30 out of 30 vaccinated mice exposed to the human 1957 H2 virus or avian H10 or H11 viruses survived, and 20 out of 24 vaccinated mice exposed to H6 virus survived and experienced less weight loss than unvaccinated mice, all of which died when exposed to virus. (medicalnewstoday.com)
  • From October 2004 to February 2005, approximately 3,700 test kits of the 1957 H2N2 virus were accidentally spread around the world from the College of American Pathologists (CAP). (wikipedia.org)
  • private contractor Meridian Bioscience in Cincinnati, U.S., chose the 1957 strand instead of one of the less deadly avian influenza virus subtypes. (wikipedia.org)
  • The 1957 H2N2 virus is considered deadly and the U.S. government called for the vials containing the strain to be destroyed. (wikipedia.org)
  • epithelial cells
  • Human lung epithelial cells (NCI-H292) was used as an in-vitro model to study cytokine/chemokine production and apoptosis induced by transfection of NS1 mRNA encoded by seven infleunza subtypes (seasonal and pandemic H1, H2, H3, H5, H7, and H9), respectively. (biomedcentral.com)
  • Severe Influenza
  • Blood plasma levels of Interleukin 6 (IL-6), Interleukin 8, monocyte chemotactic protein-1 and Interferon-gamma were significantly increased in swine H2N3 compared to human H2N2 infected animals supporting the previously published notion of increased IL-6 levels being a potential marker for severe influenza infections. (wikipedia.org)