title: Hepatitis A vaccine response in HIV-infected patients: are TWINRIX and HAVRIX interchangeable?
abstract: BACKGROUND
  Hepatitis A virus (HAV) infection remains a health risk for human immunodeficiency virus (HIV)-infected persons. Seroconversion rates among HAV vaccinated HIV-infected patients have been shown to be reduced compared to the general population. Current guidelines regard HAV vaccines as interchangeable, however there no published data comparing their efficacy in HIV patients. Our study evaluated the impact of different factors, including type of vaccination, on the immunologic response to hepatitis A vaccination in HIV-infected patients in the HAART era.
  
  
  METHODS
  This was a retrospective review of 226 HIV-infected patients at our clinic in Newark, NJ. Patients were eligible if at least one dose HAVRIX (1440 ELISA units) or TWINRIX (720 ELISA units) was administered and had anti-HAV antibody data pre- and post-vaccination. Numerous variables were evaluated for their effect on seroconversion.
  
  
  RESULTS
  Seroconversion developed in 53.5% of the population. Responders had higher baseline median CD4 counts (446 versus 362 cells/mm(3); P=0.004) and lower median HIV RNA levels (475 copies/mL versus 5615 copies/mL; P=0.018) than non-responders. Patients with CD4 counts>350 cell/mm(3) were more likely to respond than those with CD4 counts<200 cell/mm(3), 60% and 35%, respectively (P=0.0498). Responders were also more likely to be virologically suppressed (48% versus 32%; P=0.0024). TWINRIX recipients had a 7-fold increased probability of seroconversion when virologically suppressed and less likely to respond if the vaccination series was not completed (OR 0.42; 95% CI 0.18-0.96).
  
  
  CONCLUSIONS
  Seroconversion rates to HAV vaccination are significantly impaired among HIV-infected patients. CD4 cell count and virologic suppression at vaccination impact response. Seroconversion among TWINRIX recipients appeared to be more sensitive to these factors and vaccine series completion in comparison to those administered HAVRIX. Among HIV-patients requiring hepatitis a and b vaccination, the advantage of TWINRIX over HAVRIX as a combination product should be reevaluated.
authors.affiliation: Saint Michael's Medical Center, 111 Central Avenue, Newark, NJ 07102, United States. dr.umbe@gmail.com
authors.forename: Humberto R
authors.initials: HR
authors.lastname: Jimenez
authors.forename: Rabih R
authors.initials: RR
authors.lastname: Hallit
authors.forename: Vincent A
authors.initials: VA
authors.lastname: Debari
authors.forename: Jihad
authors.initials: J
authors.lastname: Slim
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D005260:Female; D006678:HIV / Q000302:isolation & purification; D015658:HIV Infections / Q000276:immunology*; D006506:Hepatitis A / Q000276:immunology / Q000517:prevention & control*; D035922:Hepatitis A Antibodies / Q000097:blood; D022362:Hepatitis A Vaccines / Q000008:administration & dosage / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood; D012189:Retrospective Studies; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000276:immunology; D019562:Viral Load
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D017325:Hepatitis B Vaccines; D012367:RNA, Viral; D017778:Vaccines, Combined; C433226:twinrix