title: Response to the influenza vaccine based on estradiol use in menopausal women.
abstract: OBJECTIVE
  To assess the impact of 17β-estradiol in modulating the response to the influenza vaccine in postmenopausal women.
  
  
  METHODS
  A prospective cohort study was conducted with 46 healthy postmenopausal women aged 41-62 years without previous vaccination against the influenza virus. Evaluation of serum antibodies using hemagglutination inhibition and single radial hemolysis was performed at the Virology Laboratory of the Butantan Institute, São Paulo, Brazil, using serum samples collected at two time points: immediately before and one month after vaccination.
  
  
  RESULTS
  In non-estradiol users (n=25), the median number of hemagglutination-inhibiting units (Log2) increased from 5.32 to 6.82 (p=0.003). In estradiol users (n=21), the median number of hemagglutination-inhibiting units (Log2) increased from 5.32 to 5.82 (p=0.149). The median hemolytic areas produced with the single radial hemolysis assay before and after the vaccine were 11 mm in both groups.
  
  
  CONCLUSIONS
  In postmenopausal women, estrogen therapy did not have a positive influence on the production of antibodies against the influenza virus after vaccination, at least based on the formulation, time period, and methods used for quantifying these antibodies in the present study.
authors: Federal University of Mato Grosso School of Medicine, Department of Gynecology and Obstetrics, Rua Almirante Henrique Pinheiro Guedes 195, Cuiabá 78043-306, MT, Brazil. Electronic address: rejaneitaborahy@gmail.com.
authors: Rejane Martins Ribeiro
authors: RM
authors: Itaborahy
authors: Butantan Institute, Virology Laboratory, Avenida Vital Brasil 1500, São Paulo 05503-900, SP, Brazil.
authors: Dalva Assunção Portari
authors: DA
authors: Mancini
authors: Federal University of Mato Grosso School of Medicine, Department of Gynecology and Obstetrics, Rua Almirante Henrique Pinheiro Guedes 195, Cuiabá 78043-306, MT, Brazil.
authors: Sebastião Freitas
authors: SF
authors: de Medeiros
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D004958:Estradiol / Q000627:therapeutic use*; D005260:Female; D006385:Hemagglutination Inhibition Tests; D020249:Hormone Replacement Therapy; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D008137:Longitudinal Studies; D008593:Menopause / Q000187:drug effects*; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines; D004958:Estradiol
keywords: Antibody; Estradiol; Influenza vaccine; Menopause