• 1
    Palese P, Shaw ML. Orthomyxoviridae: the viruses and their replication; in KnipeDM, HowleyPM, GriffinDE, LambRA, MartinMA, RoizmanB et al. (eds). Fields Virology, 5th edn. Philadelphia, Wolters Kluwer: Lippincott Williams & Wilkins, 2007; 16471689.
  • 2
    Wright PF, Neumann G, Kawaoka Y. Orthomyxoviuses; in KnipeDM, HowleyPM, GriffinDE et al. (eds): Fields Virology, 5th edn. Philadelphia: Wolters Kluwer: Lippincott Williams & Wilkins, 2007; 17271740.
  • 3
    Neumann G, Noda T, Kawaoka Y. Emergence and pandemic potential of swine-origin H1N1 influenza virus. Nature 2009; 459:931939.
  • 4
    Peiris JS, Poon LL, Guan Y. Emergence of a novel swine-origin influenza A virus (S-OIV) H1N1 virus in humans. J Clin Virol 2009; 45:169173.
  • 5
    Peiris JS, Tu WW, Yen HL. A novel H1N1 virus causes the first pandemic of the 21st century. Eur J Immunol 2009; 39:29462954.
  • 6
    Brockwell-Staats C, Webster RG, Webby RJ. Diversity of influenza viruses in swine and the emergence of a novel human pandemic influenza A (H1N1). Influenza Other Respi Viruses 2009; 3:207213.
  • 7
    Swine influenza A (H1N1) infection in two children-Southern California, March–April 2009. MMWR Morb Mortal Wkly Rep 2009;58:400402.
  • 8
    Dawood FS, Jain S, Finelli L et al. Emergence of a novel swine-origin influenza A (H1N1) virus in humans. N Engl J Med 2009; 360:26052615.
  • 9
    Cohen J, Enserink M. Infectious diseases. As swine flu circles globe, scientists grapple with basic questions. Science 2009; 324:572573.
  • 10
    Outbreak of swine-origin influenza A (H1N1) virus infection – Mexico, March–April 2009. MMWR Morb Mortal Wkly Rep 2009;58:467470.
  • 11
    Cohen J. Swine flu outbreak. Out of Mexico? Scientists ponder swine flu’s origins. Science 2009; 324:700702.
  • 12
    Update: novel influenza A (H1N1) virus infection – Mexico, March–May, 2009. MMWR Morb Mortal Wkly Rep 2009;58:585589.
  • 13
    Update: swine influenza A (H1N1) infections – California and Texas, April 2009. MMWR Morb Mortal Wkly Rep 2009;58(16):435437.
  • 14
    Zarocostas J. World Health Organization declares A (H1N1) influenza pandemic. BMJ 2009; 338:b2425.
  • 15
    Cohen J, Enserink M. Swine flu. After delays, WHO agrees: the 2009 pandemic has begun. Science 2009; 324:14961497.
  • 16
    Update: influenza activity – United States, August 30, 2009–March 27, 2010, and composition of the 2010–11 influenza vaccine. MMWR Morb Mortal Wkly Rep 2010;59:423430.
  • 17
    Fraser C, Donnelly CA, Cauchemez S et al. Pandemic potential of a strain of influenza A (H1N1): early findings. Science 2009; 324:15571561.
  • 18
    Yang Y, Sugimoto JD, Halloran ME et al. The transmissibility and control of pandemic influenza A (H1N1) virus. Science 2009; 326:729733.
  • 19
    Echevarria-Zuno S, Mejia-Arangure JM, Mar-Obeso AJ et al. Infection and death from influenza A H1N1 virus in Mexico: a retrospective analysis. Lancet 2009; 374:20722079.
  • 20
    Chowell G, Bertozzi SM, Colchero MA et al. Severe respiratory disease concurrent with the circulation of H1N1 influenza. N Engl J Med 2009; 361:674679.
  • 21
    Presanis AM, De Angelis D, Hagy A et al. The severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis. PLoS Med 2009; 6:e1000207.
  • 22
    Human infection with new influenza A (H1N1) virus: clinical observations from Mexico and other affected countries, May 2009. Wkly Epidemiol Rec 2009;84:185189.
  • 23
    Presanis AM, Lipsitch M, Daniela De A et al. The severity of pandemic H1N1 influenza in the United States, April–July 2009. PLoS Curr 2009:RRN1042, e1000207.
  • 24
    Update: novel influenza A (H1N1) virus infections – worldwide, May 6, 2009. MMWR Morb Mortal Wkly Rep 2009; 58:453458.
  • 25
    Hospitalized patients with novel influenza A (H1N1) virus infection – California, April–May, 2009. MMWR Morb Mortal Wkly Rep 2009; 58:536541.
  • 26
    Shinde V, Bridges CB, Uyeki TM et al. Triple-reassortant swine influenza A (H1) in humans in the United States, 2005–2009. N Engl J Med 2009; 360:26162625.
  • 27
    Human infection with pandemic A (H1N1) 2009 influenza virus: clinical observations in hospitalized patients, Americas, July 2009 – update. Wkly Epidemiol Rec 2009;84:305308.
  • 28
    Perez-Padilla R, de la Rosa-Zamboni D, Ponce de Leon S et al. Pneumonia and respiratory failure from swine-origin influenza A (H1N1) in Mexico. N Engl J Med 2009; 361:680689.
  • 29
    Cao B, Li XW, Mao Y et al. Clinical features of the initial cases of 2009 pandemic influenza A (H1N1) virus infection in China. N Engl J Med 2009; 361:25072517.
  • 30
    Zarocostas J. H1N1 pandemic flu found to cause viral pneumonia in severe cases, says WHO. BMJ 2009; 339:b4313.
  • 31
    Soto-Abraham MV, Soriano-Rosas J, Diaz-Quinonez A et al. Pathological changes associated with the 2009 H1N1 virus. N Engl J Med 2009; 361:20012003.
  • 32
    Tran TH, Nguyen TL, Nguyen TD et al. Avian influenza A (H5N1) in 10 patients in Vietnam. N Engl J Med 2004; 350:11791188.
  • 33
    Beigel JH, Farrar J, Han AM et al. Avian influenza A (H5N1) infection in humans. N Engl J Med 2005; 353:13741385.
  • 34
    Chotpitayasunondh T, Ungchusak K, Hanshaoworakul W et al. Human disease from influenza A (H5N1), Thailand, 2004. Emerg Infect Dis 2005; 11:201209.
  • 35
    Bacterial coinfections in lung tissue specimens from fatal cases of 2009 pandemic influenza A (H1N1) – United States, May–August 2009. MMWR Morb Mortal Wkly Rep 2009;58:10711074.
  • 36
    Palacios G, Hornig M, Cisterna D et al. Streptococcus pneumoniae coinfection is correlated with the severity of H1N1 pandemic influenza. PLoS ONE 2009; 4:e8540.
  • 37
    Lockman JL, Fischer WA, Perl TM, Valsamakis A, Nichols DG. The critically ill child with novel H1N1 influenza A: a case series. Pediatr Crit Care Med 2010; 11:173178.
  • 38
    Jamieson DJ, Honein MA, Rasmussen SA et al. H1N1 2009 influenza virus infection during pregnancy in the USA. Lancet 2009; 374:451458.
  • 39
    Baker M, Kelly H, Wilson N. Pandemic H1N1 influenza lessons from the southern hemisphere. Euro Surveill 2009; 14:19370.
  • 40
    Louie JK, Acosta M, Jamieson DJ, Honein MA. Severe 2009 H1N1 influenza in pregnant and postpartum women in California. N Engl J Med 2010; 362:2735.
  • 41
    Novel influenza A (H1N1) virus infections in three pregnant women – United States, April–May 2009. MMWR Morb Mortal Wkly Rep 2009;58:497500.
  • 42
    Zarychanski R, Stuart TL, Kumar A et al. Correlates of severe disease in patients with 2009 pandemic influenza (H1N1) virus infection. CMAJ 2010; 182:257264.
  • 43
    Garten RJ, Davis CT, Russell CA et al. Antigenic and genetic characteristics of swine-origin 2009 A(H1N1) influenza viruses circulating in humans. Science 2009; 325:197201.
  • 44
    Trifonov V, Khiabanian H, Rabadan R. Geographic dependence, surveillance, and origins of the 2009 influenza A (H1N1) virus. N Engl J Med 2009; 361:115119.
  • 45
    Smith GJ, Vijaykrishna D, Bahl J et al. Origins and evolutionary genomics of the 2009 swine-origin H1N1 influenza A epidemic. Nature 2009; 459:11221125.
  • 46
    Olsen CW. The emergence of novel swine influenza viruses in North America. Virus Res 2002; 85:199210.
  • 47
    Kida H, Ito T, Yasuda J et al. Potential for transmission of avian influenza viruses to pigs. J Gen Virol 1994; 75:21832188.
  • 48
    Scholtissek C, Burger H, Kistner O, Shortridge KF. The nucleoprotein as a possible major factor in determining host specificity of influenza H3N2 viruses. Virology 1985; 147:287294.
  • 49
    Hodder RA, Gaydos JC, Allen RG, Top FH Jr, Nowosiwsky T, Russell PK. Swine influenza A at Fort Dix, New Jersey (January–February 1976). III. Extent of spread and duration of the outbreak. J Infect Dis 1977; 136(Suppl):S369S375.
  • 50
    Gaydos JC, Hodder RA, Top FH Jr et al. Swine influenza A at Fort Dix, New Jersey (January–February 1976). II. Transmission and morbidity in units with cases. J Infect Dis 1977; 136(Suppl):S363S368.
  • 51
    Gaydos JC, Hodder RA, Top FH Jr et al. Swine influenza A at Fort Dix, New Jersey (January–February 1976). I. Case finding and clinical study of cases. J Infect Dis 1977; 136(Suppl):S356S362.
  • 52
    Myers KP, Olsen CW, Gray GC. Cases of swine influenza in humans: a review of the literature. Clin Infect Dis 2007; 44:10841088.
  • 53
    Dacso CC, Couch RB, Six HR, Young JF, Quarles JM, Kasel JA. Sporadic occurrence of zoonotic swine influenza virus infections. J Clin Microbiol 1984; 20:833835.
  • 54
    Wentworth DE, Thompson BL, Xu X et al. An influenza A (H1N1) virus, closely related to swine influenza virus, responsible for a fatal case of human influenza. J Virol 1994; 68:20512058.
  • 55
    Bastien N, Antonishyn NA, Brandt K et al. Human infection with a triple-reassortant swine influenza A(H1N1) virus containing the hemagglutinin and neuraminidase genes of seasonal influenza virus. J Infect Dis 2010; 201:11781182.
  • 56
    Van Reeth K, Nicoll A. A human case of swine influenza virus infection in Europe – implications for human health and research. Euro Surveill 2009;14:19124.
  • 57
    Cohen J. Swine flue outbreak. Flu researchers train sights on novel tricks of novel H1N1. Science 2009; 324:870871.
  • 58
    Rambaut A, Holmes E. The early molecular epidemiology of the swine-origin A/H1N1 human influenza pandemic. PLoS Curr 2009:RRN1003.
  • 59
    Ding N, Wu N, Xu Q, Chen K, Zhang C. Molecular evolution of novel swine-origin A/H1N1 influenza viruses among and before human. Virus Genes 2009; 39:293300.
  • 60
    Solovyov A, Greenbaum B, Palacios G, Lipkin WI, Rabadan R. Host dependent evolutionary patterns and the origin of 2009 H1N1 pandemic influenza: Alexander Solovyov*, Benjamin Greenbaum*, Gustavo Palacios, W. Ian Lipkin and Raul Rabadan (*Joint First Authors). PLoS Curr 2010:RRN1147.
  • 61
    Lange E, Kalthoff D, Blohm U et al. Pathogenesis and transmission of the novel swine-origin influenza virus A/H1N1 after experimental infection of pigs. J Gen Virol 2009; 90:21192123.
  • 62
    Brookes SM, Irvine RM, Nunez A et al. Influenza A (H1N1) infection in pigs. Vet Rec 2009; 164:760761.
  • 63
    Weingartl HM, Berhane Y, Hisanaga T et al. Genetic and pathobiologic characterization of pandemic H1N1 2009 influenza viruses from a naturally infected swine herd. J Virol 2010; 84:22452256.
  • 64
    Vincent AL, Lager KM, Faaberg KS et al. Experimental inoculation of pigs with pandemic H1N1 2009 virus and HI cross-reactivity with contemporary swine influenza virus antisera. Influenza Other Respi Viruses 2010; 4:5360.
  • 65
    Brookes SM, Nunez A, Choudhury B et al. Replication, pathogenesis and transmission of pandemic (H1N1) 2009 virus in non-immune pigs. PLoS ONE 2010; 5:e9068.
  • 66
    Hofshagen M, Gjerset B, Er C et al. Pandemic influenza A(H1N1)v: human to pig transmission in Norway? Euro Surveill 2009;14:19406.
  • 67
    Howden KJ, Brockhoff EJ, Caya FD et al. An investigation into human pandemic influenza virus (H1N1) 2009 on an Alberta swine farm. Can Vet J 2009; 50:11531161.
  • 68
    Pasma T, Joseph T. Pandemic (H1N1) 2009 infection in swine herds, Manitoba, Canada. Emerg Infect Dis 2010; 16:706708.
  • 69
    Babiuk S, Albrecht R, Berhane Y et al. 1918 and 2009 H1N1 influenza viruses are not pathogenic in birds. J Gen Virol 2010; 2:339342.
  • 70
    Swayne DE, Pantin-Jackwood M, Kapczynski D, Spackman E, Suarez DL. Susceptibility of poultry to pandemic (H1N1) 2009 virus. Emerg Infect Dis 2009; 15:20612063.
  • 71
    Terregino C, De Nardi R, Nisi R et al. Resistance of turkeys to experimental infection with an early 2009 Italian human influenza A(H1N1)v virus isolate. Euro Surveill 2009; 14:19360.
  • 72
    Ilyushina NA, Kim JK, Negovetich NJ et al. Extensive mammalian ancestry of pandemic (H1N1) 2009 virus. Emerg Infect Dis 2010; 16:314317.
  • 73
    Mathieu C, Moreno V, Retamal P et al. Pandemic (H1N1) 2009 in Breeding Turkeys, Valparaiso, Chile. Emerg Infect Dis 2010; 16:709711.
  • 74
    Itoh Y, Shinya K, Kiso M et al. In vitro and in vivo characterization of new swine-origin H1N1 influenza viruses. Nature 2009; 460:10211025.
  • 75
    Maines TR, Jayaraman A, Belser JA et al. Transmission and pathogenesis of swine-origin 2009 A(H1N1) influenza viruses in ferrets and mice. Science 2009; 325:484487.
  • 76
    Munster VJ, de Wit E, van den Brand JM et al. Pathogenesis and transmission of swine-origin 2009 A(H1N1) influenza virus in ferrets. Science 2009; 325:481483.
  • 77
    Perez DR, Sorrell E, Angel M et al. Fitness of pandemic H1N1 and seasonal influenza A viruses during co-infection: evidence of competitive advantage of pandemic H1N1 influenza versus seasonal influenza. PLoS Curr 2009:RRN1011.
  • 78
    van den Brand JM, Stittelaar KJ, van Amerongen G et al. Severity of pneumonia due to new H1N1 influenza virus in ferrets is intermediate between that due to seasonal H1N1 virus and highly pathogenic avian influenza H5N1 virus. J Infect Dis 2010; 201:993999.
  • 79
    Belser JA, Wadford DA, Pappas C et al. Pathogenesis of pandemic influenza A (H1N1) and triple-reassortant swine influenza A (H1) viruses in mice. J Virol 2010; 84:41944203.
  • 80
    Chen GW, Shih SR. Genomic signatures of influenza A pandemic (H1N1) 2009 virus. Emerg Infect Dis 2009; 15:18971903.
  • 81
    Furuse Y, Suzuki A, Oshitani H. Reassortment between swine influenza A viruses increased their adaptation to humans in pandemic H1N1/09. Infect Genet Evol 2010; 10:569574.
  • 82
    Pan C, Cheung B, Tan S et al. Genomic signature and mutation trend analysis of pandemic (H1N1) 2009 influenza A virus. PLoS ONE 2010; 5:e9549.
  • 83
    Karlas A, Machuy N, Shin Y et al. Genome-wide RNAi screen identifies human host factors crucial for influenza virus replication. Nature 2010; 7282:818822.
  • 84
    Shapira SD, Gat-Viks I, Shum BO et al. A physical and regulatory map of host-influenza interactions reveals pathways in H1N1 infection. Cell 2009; 139:12551267.
  • 85
    Carette JE, Guimaraes CP, Varadarajan M et al. Haploid genetic screens in human cells identify host factors used by pathogens. Science 2009; 326:12311235.
  • 86
    Rogers GN, Paulson JC. Receptor determinants of human and animal influenza virus isolates: differences in receptor specificity of the H3 hemagglutinin based on species of origin. Virology 1983; 127:361373.
  • 87
    Ito T, Couceiro JN, Kelm S et al. Molecular basis for the generation in pigs of influenza A viruses with pandemic potential. J Virol 1998; 72:73677373.
  • 88
    Shinya K, Ebina M, Yamada S, Ono M, Kasai N, Kawaoka Y. Avian flu: influenza virus receptors in the human airway. Nature 2006; 440:435436.
  • 89
    van Riel D, Munster VJ, de Wit E et al. H5N1 virus attachment to lower respiratory tract. Science 2006; 312:399.
  • 90
    Nelli RK, Kuchipudi SV, White GA, Perez BB, Dunham SP, Chang KC. Comparative distribution of human and avian type sialic acid influenza receptors in the pig. BMC Vet Res 2010; 6:4.
  • 91
    Van Poucke SG, Nicholls JM, Nauwynck HJ, Van Reeth K. Replication of avian, human and swine influenza viruses in porcine respiratory explants and association with sialic acid distribution. Virol J 2010; 7:38.
  • 92
    Stevens J, Corper AL, Basler CF, Taubenberger JK, Palese P, Wilson IA. Structure of the uncleaved human H1 hemagglutinin from the extinct 1918 influenza virus. Science 2004; 303:18661870.
  • 93
    Yang H, Carney P, Stevens J Structure and receptor binding properties of a pandemic H1N1 virus hemagglutinin. PLoS Curr 2010:RRN1152.
  • 94
    Childs RA, Palma AS, Wharton S et al. Receptor-binding specificity of pandemic influenza A (H1N1) 2009 virus determined by carbohydrate microarray. Nat Biotechnol 2009; 27:797799.
  • 95
    Kilander A, Rykkvin R, Dudman SG, Hungnes O Observed association between the HA1 mutation D222G in the 2009 pandemic influenza A(H1N1) virus and severe clinical outcome, Norway 2009–2010. Euro Surveill 2010;15(9).
  • 96
    Mak GC, Au KW, Tai LS et al. Association of D222G substitution in haemagglutinin of 2009 pandemic influenza A (H1N1) with severe disease. Euro Surveill 2010;15:19534.
  • 97
    Glinsky GV. Genomic analysis of pandemic (H1N1) 2009 reveals association of increasing disease severity with emergence of novel hemagglutinin mutations. Cell Cycle 2010; 9:958970.
  • 98
    Potdar VA, Chadha MS, Jadhav SM, Mullick J, Cherian SS, Mishra AC. Genetic characterization of the influenza A pandemic (H1N1) 2009 virus isolates from India. PLoS ONE 2010; 5:e9693.
  • 99
    Miller RR, MacLean AR, Gunson RN, Carman WF. Occurrence of haemagglutinin mutation D222G in pandemic influenza A(H1N1) infected patients in the West of Scotland, United Kingdom, 2009–10. Euro Surveill 2010; 15:19546.
  • 100
    Preliminary review of D222G amino acid substitution in the haemagglutinin of pandemic influenza A (H1N1) 2009 viruses. Wkly Epidemiol Rec 2010;85:2122.
  • 101
    Anton A, Marcos MA, Martinez MJ et al. D225G mutation in the hemagglutinin protein found in 3 severe cases of 2009 pandemic influenza A (H1N1) in Spain. Diagn Microbiol Infect Dis 2010; 67:207208.
  • 102
    Chen H, Wen X, To KK et al. Quasispecies of the D225G substitution in the hemagglutinin of pandemic influenza A(H1N1) 2009 virus from patients with severe disease in Hong Kong, China. J Infect Dis 2010; 201:15171521.
  • 103
    Puzelli S, Facchini M, Spagnolo D et al. Transmission of hemagglutinin D222G mutant strain of pandemic (H1N1) 2009 virus. Emerg Infect Dis 2010; 16:863865.
  • 104
    Igarashi M, Ito K, Yoshida R, Tomabechi D, Kida H, Takada A. Predicting the antigenic structure of the pandemic (H1N1) 2009 influenza virus hemagglutinin. PLoS ONE 2010; 5:e8553.
  • 105
    Xu R, Ekiert DC, Krause JC, Hai R, Crowe JE Jr, Wilson IA. Structural basis of preexisting immunity to the 2009 H1N1 pandemic influenza virus. Science 2010; 328:357360.
  • 106
    Greenbaum JA, Kotturi MF, Kim Y et al. Pre-existing immunity against swine-origin H1N1 influenza viruses in the general human population. Proc Natl Acad Sci U S A 2009; 106:2036520370.
  • 107
    Krause JC, Tumpey TM, Huffman CJ et al. Naturally occurring human monoclonal antibodies neutralize both 1918 and 2009 pandemic influenza A (H1N1) viruses. J Virol 2010; 84:31273130.
  • 108
    Manicassamy B, Medina RA, Hai R et al. Protection of mice against lethal challenge with 2009 H1N1 influenza A virus by 1918-like and classical swine H1N1 based vaccines. PLoS Pathog 2010; 6:e1000745.
  • 109
    Wei CJ, Boyington JC, Dai K et al. Cross-neutralization of 1918 and 2009 influenza viruses: role of glycans in viral evolution and vaccine design. Sci Transl Med 2010; 2:24ra1.
  • 110
    Hancock K, Veguilla V, Lu X et al. Cross-reactive antibody responses to the 2009 pandemic H1N1 influenza virus. N Engl J Med 2009; 361:19451952.
  • 111
    Ikonen N, Strengell M, Kinnunen L et al. High frequency of cross-reacting antibodies against 2009 pandemic influenza A(H1N1) virus among the elderly in Finland. Euro Surveill 2010;15:19478.
  • 112
    Serum cross-reactive antibody response to a novel influenza A (H1N1) virus after vaccination with seasonal influenza vaccine. MMWR Morb Mortal Wkly Rep 2009;58:521524.
  • 113
    Caton AJ, Brownlee GG, Yewdell JW, Gerhard W. The antigenic structure of the influenza virus A/PR/8/34 hemagglutinin (H1 subtype). Cell 1982; 31:417427.
  • 114
    Gerhard W, Yewdell J, Frankel ME, Webster R. Antigenic structure of influenza virus haemagglutinin defined by hybridoma antibodies. Nature 1981; 290:713717.
  • 115
    Hatta M, Gao P, Halfmann P, Kawaoka Y. Molecular basis for high virulence of Hong Kong H5N1 influenza A viruses. Science 2001; 293:18401842.
  • 116
    Subbarao EK, London W, Murphy BR. A single amino acid in the PB2 gene of influenza A virus is a determinant of host range. J Virol 1993; 67:17611764.
  • 117
    Herfst S, Chutinimitkul S, Ye J et al. Introduction of virulence markers in PB2 of pandemic swine-origin influenza virus does not result in enhanced virulence or transmission. J Virol 2010; 84:37523758.
  • 118
    Zhu H, Wang J, Wang P et al. Substitution of lysine at 627 position in PB2 protein does not change virulence of the 2009 pandemic H1N1 virus in mice. Virology 2010; 401:15.
  • 119
    Mehle A, Doudna JA. Adaptive strategies of the influenza virus polymerase for replication in humans. Proc Natl Acad Sci U S A 2009; 106:2131221316.
  • 120
    Yamada S, Hatta M, Staker B et al. Biological and structural characterization of a host-adapting amino acid in influenza virus. PLoS Pathog, 2010; 5: e1001034.
  • 121
    Mehle A, Doudna JA. An inhibitory activity in human cells restricts the function of an avian-like influenza virus polymerase. Cell Host Microbe 2008; 4:111122.
  • 122
    Li Z, Chen H, Jiao P et al. Molecular basis of replication of duck H5N1 influenza viruses in a mammalian mouse model. J Virol 2005; 79:1205812064.
  • 123
    Bussey KA, Bousse TL, Desmet EA, Kim B, Takimoto T. PB2 residue 271 plays a key role in enhanced polymerase activity of influenza A viruses in mammalian host cells. J Virol 2010; 84:43954406.
  • 124
    Garcia-Sastre A, Egorov A, Matassov D et al. Influenza A virus lacking the NS1 gene replicates in interferon-deficient systems. Virology 1998; 252:324330.
  • 125
    Krug RM, Yuan W, Noah DL, Latham AG. Intracellular warfare between human influenza viruses and human cells: the roles of the viral NS1 protein. Virology 2003; 309:181189.
  • 126
    Hale BG, Randall RE, Ortin J, Jackson D. The multifunctional NS1 protein of influenza A viruses. J Gen Virol 2008; 89:23592376.
  • 127
    Seo SH, Hoffmann E, Webster RG. Lethal H5N1 influenza viruses escape host anti-viral cytokine responses. Nat Med 2002; 8:950954.
  • 128
    Obenauer JC, Denson J, Mehta PK et al. Large-scale sequence analysis of avian influenza isolates. Science 2006; 311:15761580.
  • 129
    Jackson D, Hossain MJ, Hickman D, Perez DR, Lamb RA. A new influenza virus virulence determinant: the NS1 protein four C-terminal residues modulate pathogenicity. Proc Natl Acad Sci U S A 2008; 105:43814386.
  • 130
    Hale BG, Steel J, Manicassamy B et al. Mutations in the NS1 C-terminal tail do not enhance replication or virulence of the 2009 pandemic H1N1 influenza A virus. J Gen Virol 2010; 91:17371742.
  • 131
    Woo PC, Tung ET, Chan KH, Lau CC, Lau SK, Yuen KY. Cytokine profiles induced by the novel swine-origin influenza A/H1N1 virus: implications for treatment strategies. J Infect Dis 2010; 201:346353.
  • 132
    Chan MC, Chan RW, Yu WC et al. Tropism and innate host responses of the 2009 pandemic H1N1 influenza virus in ex vivo and in vitro cultures of human conjunctiva and respiratory tract. Am J Pathol 2010; 176:18281840.
  • 133
    To KK, Hung IF, Li IW et al. Delayed clearance of viral load and marked cytokine activation in severe cases of pandemic H1N1 2009 influenza virus infection. Clin Infect Dis 2010; 50:850859.
  • 134
    de Castro IF, Guzman-Fulgencio M, Garcia-Alvarez M, Resino S. First evidence of a pro-inflammatory response to severe infection with influenza virus H1N1. Crit Care 2010; 14:115.
  • 135
    Bermejo-Martin JF, Ortiz de Lejarazu R, Pumarola T et al. Th1 and Th17 hypercytokinemia as early host response signature in severe pandemic influenza. Crit Care 2009; 13:R201.
  • 136
    Conenello GM, Palese P. Influenza A virus PB1-F2: a small protein with a big punch. Cell Host Microbe 2007; 2:207209.
  • 137
    Hai R, Schmolke M, Varga ZT et al. PB1-F2 expression by the 2009 pandemic H1N1 influenza virus has minimal impact on virulence in animal models. J Virol 2010; 84:44424450.
  • 138
    Update: drug susceptibility of swine-origin influenza A (H1N1) viruses, April 2009. MMWR Morb Mortal Wkly Rep 2009;58:433435.
  • 139
    Oseltamivir-resistant novel influenza A (H1N1) virus infection in two immunosuppressed patients – Seattle, Washington, 2009. MMWR Morb Mortal Wkly Rep 2009;58:893896.
  • 140
    Leung TW, Tai AL, Cheng PK, Kong MS, Lim W. Detection of an oseltamivir-resistant pandemic influenza A/H1N1 virus in Hong Kong. J Clin Virol 2009; 46:298299.
  • 141
    Chen H, Cheung CL, Tai H et al. Oseltamivir-resistant influenza A pandemic (H1N1) 2009 virus, Hong Kong, China. Emerg Infect Dis 2009; 15:19701972.
  • 142
    Baz M, Abed Y, Papenburg J, Bouhy X, Hamelin ME, Boivin G. Emergence of oseltamivir-resistant pandemic H1N1 virus during prophylaxis. N Engl J Med 2009; 361:22962297.
  • 143
    Gulland A. First cases of spread of oseltamivir resistant swine flu between patients are reported in Wales. BMJ 2009; 339:b4975.
  • 144
    Le QM, Wertheim HF, Tran ND, van Doorn HR, Nguyen TH, Horby P. A community cluster of oseltamivir-resistant cases of 2009 H1N1 influenza. N Engl J Med 2010; 362:8687.
  • 145
    Gaur AH, Bagga B, Barman S et al. Intravenous zanamivir for oseltamivir-resistant 2009 H1N1 influenza. N Engl J Med 2010; 362:8889.
  • 146
    Birnkrant D, Cox E. The Emergency Use Authorization of peramivir for treatment of 2009 H1N1 influenza. N Engl J Med 2009; 361:22042207.
  • 147
    Valdespino-Gomez JL, Garcia-Garcia L, de Leon-Rosales SP. Vaccines against influenza A (H1N1) pandemic. Arch Med Res 2009; 40:693704.
  • 148
    Dormitzer PR, Rappuoli R, Casini D et al. Adjuvant is necessary for a robust immune response to a single dose of H1N1 pandemic flu vaccine in mice. PLoS Curr. 2009:RRN1025.
  • 149
    Kobinger GP, Meunier I, Patel A et al. Assessment of the efficacy of commercially available and candidate vaccines against a pandemic H1N1 2009 virus. J Infect Dis 2010; 201:10001006.
  • 150
    Willyard C. Pandemic vaccine enters clinical trials. Nat Med 2009; 15:978.
  • 151
    Greenberg ME, Lai MH, Hartel GF et al. Response to a monovalent 2009 influenza A (H1N1) vaccine. N Engl J Med 2009; 361:24052413.
  • 152
    Clark TW, Pareek M, Hoschler K et al. Trial of 2009 influenza A (H1N1) monovalent MF59-adjuvanted vaccine. N Engl J Med 2009; 361:24242435.
  • 153
    Roman F, Vaman T, Gerlach B, Markendorf A, Gillard P, Devaster JM. Immunogenicity and safety in adults of one dose of influenza A H1N1v 2009 vaccine formulated with and without AS03A-adjuvant: preliminary report of an observer-blind, randomised trial. Vaccine 2010; 28:17401745.
  • 154
    Vajo Z, Tamas F, Sinka L, Jankovics I. Safety and immunogenicity of a 2009 pandemic influenza A H1N1 vaccine when administered alone or simultaneously with the seasonal influenza vaccine for the 2009–10 influenza season: a multicentre, randomised controlled trial. Lancet 2010; 375:4955.
  • 155
    Liang XF, Wang HQ, Wang JZ et al. Safety and immunogenicity of 2009 pandemic influenza A H1N1 vaccines in China: a multicentre, double-blind, randomised, placebo-controlled trial. Lancet 2010; 375:5666.
  • 156
    Plennevaux E, Sheldon E, Blatter M, Reeves-Hoche MK, Denis M. Immune response after a single vaccination against 2009 influenza A H1N1 in USA: a preliminary report of two randomised controlled phase 2 trials. Lancet 2010; 375:4148.
  • 157
    Zhu FC, Wang H, Fang HH et al. A novel influenza A (H1N1) vaccine in various age groups. N Engl J Med 2009; 361:24142423.
  • 158
    Nolan T, McVernon J, Skeljo M et al. Immunogenicity of a monovalent 2009 influenza A(H1N1) vaccine in infants and children: a randomized trial. JAMA 2010; 303:3746.
  • 159
    Safety of influenza A (H1N1) 2009 monovalent vaccines – United States, October 1–November 24, 2009. MMWR Morb Mortal Wkly Rep 2009; 58:13511356.
  • 160
    Update on influenza A (H1N1) 2009 monovalent vaccines. MMWR Morb Mortal Wkly Rep. 2009; 58:11001101.
  • 161
    Johansen K, Nicoll A, Ciancio BC, Kramarz P. Pandemic influenza A(H1N1) 2009 vaccines in the European Union. Euro Surveill 2009; 14:19361.