• 1
    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. Vaccine2010; 28:17401745.
  • 2
    Roman F, Vaman T, Kafeja F, Hanon E, Van Damme P. AS03(A)-Adjuvanted influenza A (H1N1) 2009 vaccine for adults up to 85 years of age. Clin Infect Dis2010; 51:668677.
  • 3
    Roman F, Clement F, Dewe W et al. Effect on cellular and humoral immune responses of the AS03 adjuvant system in an A/H1N1/2009 influenza virus vaccine administered to adults during two randomized controlled trials. Clin Vaccine Immunol2011; 18:835843.
  • 4
    Costa JT, Silva R, Tavares M, Nienhaus A. High effectiveness of pandemic influenza A (H1N1) vaccination in healthcare workers from a Portuguese hospital. Int Arch Occup Environ Health2011; DOI 10.1007/s00420-011-0714-8 [Epub ahead of print].
  • 5
    Gilca V, De Serres G, Hamelin ME et al. Antibody persistence and response to 2010-2011 trivalent influenza vaccine one year after a single dose of 2009 AS03-adjuvanted pandemic H1N1 vaccine in children. Vaccine2011; 30:3541.
  • 6
    Strengell M, Ikonen N, Ziegler T, Julkunen I. Minor changes in the hemagglutinin of influenza A(H1N1)2009 virus alter its antigenic properties. PLoS ONE2011; 6:e25848.
  • 7
    European Medicines Agency. Pandemrix. Summary of product characteristics. Available from: (Accessed 16 August 2012).
  • 8
    Ikonen N, Haanpaa M, Ronkko E et al. Genetic diversity of the 2009 pandemic influenza A(H1N1) viruses in Finland. PLoS ONE2010; 5:e13329.
  • 9
    Tamura K, Dudley J, Nei M, Kumar S. MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0. Mol Biol Evol2007; 24:15961599.
  • 10
    Saitou N, Nei M. The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol1987; 4:406425.
  • 11
    Tamura K, Nei M, Kumar S. Prospects for inferring very large phylogenies by using the neighbor-joining method. Proc Natl Acad Sci USA2004; 101:1103011035.
  • 12
    Hillis DM, Allard MW, Miyamoto MM. Analysis of DNA sequence data: phylogenetic inference. Methods Enzymol1993; 224:456487.
  • 13
    Sayle RA, Milner-White EJ. RASMOL: biomolecular graphics for all. Trends Biochem Sci1995; 20:374.
  • 14
    Kendal AP, Pereira MS, Skehel JJ. Concepts and Procedures for Laboratory-Based Influenza Surveillance. WHO Collaborating Centers for Reference and Research on Influenza. Washington, D.C.: U.S. Dept. of Health and Human Services, 1982.
  • 15
    World Health Organization, Global Influenza Surveillance Network. Manual for the Laboratory Diagnosis and Virological Surveillance of Influenza. Geneva, Switzerland: World Health Organization; 2011.
  • 16
    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 Surveill2010; 15:19478.
  • 17
    Allwinn R, Geiler J, Berger A, Cinatl J, Doerr HW. Determination of serum antibodies against swine-origin influenza A virus H1N1/09 by immunofluorescence, haemagglutination inhibition, and by neutralization tests: how is the prevalence rate of protecting antibodies in humans?Med Microbiol Immunol2010; 199:117121.
  • 18
    Hardelid P, Andrews NJ, Hoschler K et al. Assessment of baseline age-specific antibody prevalence and incidence of infection to novel influenza A/H1N1 2009. Health Technol Assess2010; 14:115192.
  • 19
    Centers for Disease Control and Prevention (CDC). Serum cross-reactive antibody response to a novel influenza A (H1N1) virus after vaccination with seasonal influenza vaccine. MMWR Morb Mortal Wkly Rep2009;58:521524.
  • 20
    Rizzo C, Rota MC, Bella A et al. Cross-reactive antibody responses to the 2009 A/H1N1v influenza virus in the Italian population in the pre-pandemic period. Vaccine2010; 28:35583562.
  • 21
    Hancock KPD, Veguilla VMPH, Lu XMD et al. Cross-Reactive Antibody Responses to the 2009 Pandemic H1N1 Influenza Virus. N Engl J Med2009; 361:19451952.
  • 22
    Broberg E, Nicoll A, Amato-Gauci A. Seroprevalence to influenza A(H1N1) 2009 virus--where are we?Clin Vaccine Immunol2011; 18:12051212.
  • 23
    Miller E, Hoschler K, Hardelid P, Stanford E, Andrews N, Zambon M. Incidence of 2009 pandemic influenza A H1N1 infection in England: a cross-sectional serological study. Lancet2010; 375:11001108.
  • 24
    Gilbert GL, Cretikos MA, Hueston L, Doukas G, O’Toole B, Dwyer DE. Influenza A (H1N1) 2009 antibodies in residents of New South Wales, Australia, after the first pandemic wave in the 2009 southern hemisphere winter. PLoS ONE2010; 5:e12562.
  • 25
    Lyytikainen O, Kuusi M, Snellman M et al. Surveillance of influenza in Finland during the 2009 pandemic, 10 May 2009 to 8 March 2010. Euro Surveill2011; 16:19908.
  • 26
    Cao W, Kim JH, Chirkova T et al. Improving immunogenicity and effectiveness of influenza vaccine in older adults. Expert Rev Vaccines.2011; 10:15291537.