effect of tetanus-diphtheria (td) vaccine on immune response to hepatitis b vaccine in healthy individuals with insufficient immune response

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. materials and 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. th e control group received 40 ?g 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 signifi cantly diff erent between the two groups (p = 0.011). conclusion: td vaccination can be applied as a feasible approach to promote efficient and persistent immunity in healthy individuals with insuffi cient hbsab titers.