title: Effect of tetanus-diphtheria (Td) vaccine on immune response to hepatitis B vaccine in healthy individuals with insufficient immune response.
abstract: BACKGROUND
  Hepatitis B virus (HBV) fails to produce appropriate immune responses in some healthy individuals; thus, different strategies have been adopted to promote immune responses. The current study aimed at evaluating the efficacy of HBV vaccine coadministered with tetanus-diphtheria (Td) vaccine compared with HBV vaccine in healthy individuals through measuring hepatitis B surface antibody (HBsAb) levels.
  
  
  METHODS
  This was a randomized controlled clinical trial, which was implemented in Isfahan, Isfahan Province (Iran) in 2013. One hundred and forty healthy individuals, whose HBsAb titers were less than 10 IU/L were recruited. The subjects were randomly assigned to either in intervention or control trials. The control group received 40 μg of recombinant HBV vaccines intramuscularly injected at 0, 1, and 6 months; however, the intervention group was simultaneously vaccinated by Td with the first dose of HBV vaccine. HBV antibody levels (titer) were measured before the vaccination and 6 months after the last vaccination.
  
  
  RESULTS
  Antibody titers of the subjects in the intervention and control groups increased from 5.07 ± 2.9 IU/L to 744.45 ± 353.07 IU/L and from 4.45 ± 3.4 IU/L to 589.94 ± 353 IU/L, respectively (both P < 0.001). Also, the mean difference of antibody titer was significantly different between the two groups (P = 0.011).
  
  
  CONCLUSIONS
  Td vaccination can be applied as a feasible approach to promote efficient and persistent immunity in healthy individuals with insufficient HBsAb titers.
authors.affiliation: Student Research Committee, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Salehi
authors.affiliation: Department of Oral Surgery, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Haghighat
authors.affiliation: Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Salehi
authors.affiliation: Department of Community Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Taleban
authors.affiliation: Student Research Committee, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Salehi
authors.affiliation: Department of Pathology, School of Dentistry, Islamic Azad University (Khorasgan Branch), Isfahan, Iran.
authors.forename: Nader
authors.initials: N
authors.lastname: Kalbasi
authors.affiliation: Acquired Immunodeficiency Research Centre, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Moafi
authors.affiliation: Student Research Committee, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad Mahdi
authors.initials: MM
authors.lastname: Salehi
keywords: Hepatitis B surface antibody (HBsAb) titer; hepatitis B vaccine; tetanus-diphtheria (Td) vaccine