1395. Duration of Hepatitis B Vaccine Responses in HIV-Infected Individuals
Session: Oral Abstract Session: Complications of HIV
Sunday, October 23, 2011: 8:30 AM
Room: 151AB
Background:  Longitudinal data on long-term seroresponse to hepatitis B (HB) vaccine in HIV-infected adults is limited. Therefore, we investigated the duration of HB vaccine seroresponse among participants enrolled in the U.S. Military HIV Natural History Study cohort (NHS).

Methods:  Eligible NHS participants were initially negative for HB infection, received all HB vaccinations after HIV diagnosis, and had a documented positive initial vaccine response, defined as a hepatitis B surface antibody (HBsAb) ≥10 IU/L detected one to twelve months following the last dose of HB vaccine. Participants were retrospectively followed with serial HB serologies from last HB vaccination until development of waning HBsAb (HBsAb <10 IU/L) or last HBsAb measurement.  Time to and risk for waning HBsAb were evaluated with Kaplan-Meier survival methods and Cox proportional hazards models, respectively.

Results:  Overall 186 initial vaccine responders vaccinated from 1997 to 2009 were identified. At last vaccination, the median CD4 count was 590 cells/mL (IQR 459 – 757), and 44% (n=81) had an undetectable HIV viral load (VL). During 570 person-years of observation, HBsAb waned in 28% (n=52). Median duration of follow-up was similar for those who waned (25 months; IQR, 18-45) compared with those who did not (20 months; IQR, 8-51; p=0.19). Overall, the median time to waning HBsAb was 99 months (95% CI, 54-144). Participants with an undetectable VL by assay (HR 0.370; 95% CI, 0.179-0.764) or with a detectable VL of <10,000 copies/mL (HR 0.459; 95% CI, 0.211-0.999) had reduced risk of waning HBsAb compared to those with a VL of ≥10,000 copies/mL at the time of last vaccination. Other factors including age, number of vaccinations, CD4 count, and HAART use were not significantly associated with risk of waning HBsAb.

Conclusion: Among HIV-infected individuals with relatively high CD4 cell counts who respond to HB vaccination, HBsAb levels ≥10 IU/L may be sustained, with a median duration of over 8 years.  The presence of an undetectable HIV viral load at the time of last vaccination may improve HB vaccine response durability.


Subject Category: H. HIV/AIDS and other retroviruses

Elizabeth Rini, MD1, Octavio Mesner, MS2, Robert O'Connell, MD3, Helen M. Chun, MD4, Jason Okulicz, MD1, Anuradha Ganesan, MD2,5, Tahaniyat Lalani, MD6,7, Mary Bavaro, MD8, Glenn Wortmann, MD9, Brian Agan, MD7 and Michael Landrum, MD1,2, (1)San Antonio Military Medical Center, Fort Sam Houston, TX, (2)Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, MD, (3)Walter Reed Army Institute of Research, Silver Spring, MD, (4)Naval Health Research Center, San Diego, CA, (5)Infectious Disease Clinic, National Naval Medical Center, Bethesda, MD, (6)Naval Medical Center, Portsmouth, VA, (7)Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Bethesda, MD, (8)Naval Medical Center, San Diego, CA, (9)Uniformed Services University, Bethesda, MD

Disclosures:

E. Rini, None

O. Mesner, None

R. O'Connell, None

H. M. Chun, None

J. Okulicz, None

A. Ganesan, None

T. Lalani, None

M. Bavaro, None

G. Wortmann, None

B. Agan, None

M. Landrum, None

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