title: Specific recognition of influenza A/H1N1/2009 antibodies in human serum: a simple virus-free ELISA method.
abstract: BACKGROUND
  Although it has been estimated that pandemic Influenza A H1N1/2009 has infected millions of people from April to October 2009, a more precise figure requires a worldwide large-scale diagnosis of the presence of Influenza A/H1N1/2009 antibodies within the population. Assays typically used to estimate antibody titers (hemagglutination inhibition and microneutralization) would require the use of the virus, which would seriously limit broad implementation.
  
  
  RESULTS
  An ELISA method to evaluate the presence and relative concentration of specific Influenza A/H1N1/2009 antibodies in human serum samples is presented. The method is based on the use of a histidine-tagged recombinant fragment of the globular region of the hemagglutinin (HA) of the Influenza A H1N1/2009 virus expressed in E. coli.
  
  
  CONCLUSIONS
  The ELISA method consistently discerns between Inf A H1N1 infected and non-infected subjects, particularly after the third week of infection/exposure. Since it does not require the use of viral particles, it can be easily and quickly implemented in any basic laboratory. In addition, in a scenario of insufficient vaccine availability, the use of this ELISA could be useful to determine if a person has some level of specific antibodies against the virus and presumably at least partial protection.
authors.affiliation: Centro de Biotecnología-FEMSA, Tecnológico de Monterrey, Monterrey, New León, México. mario.alvarez@itesm.mx
authors.forename: Mario M
authors.initials: MM
authors.lastname: Alvarez
authors.forename: Felipe
authors.initials: F
authors.lastname: López-Pacheco
authors.forename: José M
authors.initials: JM
authors.lastname: Aguilar-Yañez
authors.forename: Roberto
authors.initials: R
authors.lastname: Portillo-Lara
authors.forename: Gonzalo I
authors.initials: GI
authors.lastname: Mendoza-Ochoa
authors.forename: Sergio
authors.initials: S
authors.lastname: García-Echauri
authors.forename: Pamela
authors.initials: P
authors.lastname: Freiden
authors.forename: Stacey
authors.initials: S
authors.lastname: Schultz-Cherry
authors.forename: Manuel I
authors.initials: MI
authors.lastname: Zertuche-Guerra
authors.forename: David
authors.initials: D
authors.lastname: Bulnes-Abundis
authors.forename: Johari
authors.initials: J
authors.lastname: Salgado-Gallegos
authors.forename: Leticia
authors.initials: L
authors.lastname: Elizondo-Montemayor
authors.forename: Martín
authors.initials: M
authors.lastname: Hernández-Torre
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000592:standards; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007251:Influenza, Human / Q000175:diagnosis*; D009500:Neutralization Tests; D012698:Serologic Tests / Q000379:methods
chemical_list: D000914:Antibodies, Viral