title: Humoral response to influenza vaccination in relation to pre-vaccination antibody titres, vaccination history, cytomegalovirus serostatus and CD4/CD8 ratio.
abstract: BACKGROUND
  Annual vaccination against influenza virus is generally recommended to elderly and chronically ill, but the relative importance of factors influencing the outcome is not fully understood.
  
  
  METHODS
  In this study of 88 individuals all aged 69 years, the increase in haemagglutinin-inhibiting (HI) antibodies to trivalent inactivated influenza vaccine was correlated with HI titres before vaccination, prior vaccinations against influenza, cytomegalovirus serostatus and, as an estimate of immune risk profile, the ratio between CD4 + and CD8 + T cells.
  
  
  RESULTS
  Vaccine responses were impaired by high pre-existing HI antibody titres. For influenza B repeated vaccinations and an inverse CD4/CD8 ratio had a negative impact on the vaccine response. Cytomegalovirus seropositivity had no apparent effect on HI titres before or after vaccination.
  
  
  CONCLUSIONS
  It is concluded that both pre-existing HI antibodies and previous vaccinations to influenza may influence the humoral response to influenza vaccination and that a CD4/CD8 ratio < 1 may indicate an impaired ability to respond to repeated antigenic stimulation.
authors.affiliation: a School of Health Sciences, Department of Natural Science and Biomedicine , Jönköping University , Jönköping , Sweden ;
authors.forename: Jan
authors.initials: J
authors.lastname: Strindhall
authors.affiliation: b Division of Clinical Immunology, Department of Molecular and Clinical Medicine, Faculty of Health Sciences , Linköping University , Linköping , Sweden ;
authors.forename: Jan
authors.initials: J
authors.lastname: Ernerudh
authors.affiliation: c Department of Microbiology , Public Health Agency of Sweden , Sweden ;
authors.forename: Andreas
authors.initials: A
authors.lastname: Mörner
authors.affiliation: d Department of Virology , Norwegian Institute of Public Health , Oslo , Norway ;
authors.forename: Kristian
authors.initials: K
authors.lastname: Waalen
authors.affiliation: e Department of Laboratory Medicine , Clinical Microbiology, Ryhov County Hospital , Jönköping , Sweden ;
authors.forename: Sture
authors.initials: S
authors.lastname: Löfgren
authors.affiliation: e Department of Laboratory Medicine , Clinical Microbiology, Ryhov County Hospital , Jönköping , Sweden ;
authors.forename: Andreas
authors.initials: A
authors.lastname: Matussek
authors.affiliation: f Department of Infectious Diseases , Ryhov County Hospital , Jönköping , Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Bengner
mesh_terms: D000368:Aged; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D000956:Antigens, Viral / Q000097:blood / Q000276:immunology; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D003587:Cytomegalovirus / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods; D006385:Hemagglutination Inhibition Tests / Q000379:methods; D006801:Humans; D056724:Immunity, Humoral; D007074:Immunoglobulin G / Q000097:blood; D000068884:Immunosenescence; D009981:Influenza B virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology* / Q000821:virology; D008297:Male
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D007074:Immunoglobulin G; D007252:Influenza Vaccines
keywords: Influenza vaccination; cytomegalovirus; immunosenescence