Role of CD4 Count in the Development of Immunity after Hepatitis A and B Vaccination in HIV/AIDS Infected Patients

Objective: To determine if lower pre-vaccination CD4 counts affect the odds of immune development against Hepatitis A (HAV) or B (HBV) post-completion of vaccination, and to determine if immune development is associated with gender, a racial social group, health insurance status, tobacco use, substance use or co-morbidities.

A case-control study was performed on HIV/AIDS patients attending the Bluegrass Care Clinic between 2002 and 2007. All patients that received HAV or HBV vaccine and had pre- and post-vaccination Hepatitis B Surface antibody or Hepatitis A antibody titers were included.

76 of the 451 patients vaccinated at the clinic met the inclusion criteria. The development of immunity to HAV and/or HBV in the patients increased as CD4 count increased. Males had greater odds for the development of immunity than females; Whites had higher rates than other races; Patients with private insurance developed higher immunity than those with Medicaid, Medicare or no insurance. More patients without AIDS (CD4< 200/mm3) were able to develop immunity than patients with AIDS. Patients without AIDS, hypertension and hyperlipidemia were observed to develop immunity more often than patients with co-morbidities. Substance abuse and tobacco use were also indicators of immunity development.

Increased CD4 count was associated with increases in immunity development. Patients with CD4 counts greater than 400/mm3 were more likely to develop immunity to HAV and/or HBV, than those with CD4 counts below 400/mm3. Racial groups, insurance status and co-morbidities impacted immunity development.