title: Response to hepatitis B vaccination among HIV-infected adults in Vietnam.
abstract: OBJECTIVE
  We sought to determine the rate of response to hepatitis B (HBV) vaccination among HIV-infected adults in Vietnam.
  
  
  METHODS
  We retrospectively abstracted data from a cohort of HIV-infected adults who had received HBV vaccine at an HIV clinic in Hanoi. We examined demographic, clinical and laboratory factors for associations with development of a protective antibody (Ab) response following vaccination (defined as 'responders' with anti-HBs >10 IU/L).
  
  
  RESULTS
  Out of 302 HIV-infected patients who completed the vaccine series and follow-up serology testing, 189 (62.6%) had a positive protective Ab response. Female patients had a higher response rate compared to male patients (71.4% vs 56.8%, P=0.01). Among responders, mean CD4 T cell count was 309 cells/μL as compared to 204 cells/μL in non-responders (P<0.0001). On multivariable analysis, CD4 T cell count prior to vaccination was the only factor independently associated with a positive Ab response. Compared to patients with a count less than 100 cells/μL, those with a CD4 T cell count between 100 and 200 cells/μL were 20% more likely to be responders (relative risk [RR] 1.20, 95% confidence interval [CI] 0.77-1.87), those with a CD4 T cell count between 200 and 300 cells/μL were 61% more likely to be responders (RR 1.61, 95% CI 1.05-2.45), and those with a CD4 T cell count greater than 300 cells/μL were 89% more likely to be responders (RR 1.89, 95% CI 1.26-2.83).
  
  
  CONCLUSIONS
  We found that the CD4 T cell count at the time of vaccination to be the sole predictor of response to HBV vaccination among HIV-infected Vietnamese adults. Our findings highlight the importance of vaccinating HIV-infected adults prior to advanced immunosuppression.
authors.affiliation: ; Harvard Medical School, Boston, USA.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Pollack
authors.affiliation: The Partnership for Health Advancement in Vietnam , Hanoi , Vietnam.
authors.forename: Le Thi Thu
authors.initials: le TT
authors.lastname: Trang
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Boston, USA; Harvard Medical School, Boston, USA.
authors.forename: Long
authors.initials: L
authors.lastname: Ngo
authors.affiliation: Department of Infectious Diseases , Bach Mai Hospital , Hanoi , Vietnam.
authors.forename: Do Duy
authors.initials: do D
authors.lastname: Cuong
authors.affiliation: Department of Infectious Diseases , Bach Mai Hospital , Hanoi , Vietnam.
authors.forename: Pham Thanh
authors.initials: PT
authors.lastname: Thuy
authors.affiliation: Center for Applied Research on Men and Health, HCMC, Vietnam; SEARCH, Thai Red Cross AIDS Research Center, Bangkok, Thailand.
authors.forename: Donn J
authors.initials: DJ
authors.lastname: Colby
keywords: CD4; HIV; Vietnam; hepatitis B; human immunodeficiency virus; vaccination