Long-term response rates of successful hepatitis B vaccination in HIV-infected patients

Data on long-term response rates after successful primary hepatitis B (HBV) vaccination in HIV-infected patients are scarce.

To evaluate the durability of an effective anti-HBs titer up to 5 years after primary vaccination in a cohort of 155 HIV-infected adults.

From a previous multicenter HBV vaccination trial we selected patients with an anti-HBs titer of ≥10 IU/l 28 weeks after the first vaccination. The anti-HBs titer was measured in annually stored plasma samples up to 5 years after vaccination. Patients with decreasing anti-HBs titers <10 IU/I were defined as transient responders (TR) and with persistent anti-HBs titers ≥10 IU/I as long-term responders (LTR^).

We included 155 patients, 87 were TR and 68 LTR. Mean age, percentage of female participants and duration of HAART use at primary vaccination were similar in LTR and TR. Anti-HBs level after primary vaccination was the strongest predictor for the durability of anti-HBs. Anti-HBs >100-1000 IU/I and >1000 resulted in an OR 8.3, 95% CI 3.38-20.16; p<0.0001 and OR 75.6, 95% CI 13.41-426.45; p<0.0001 versus anti-HBs titer of 10-100 IU/I after primary vaccination respectively. The mean time to loss of an effective anti-HBs titer was 2.0, 3.7 and 4.4 years respectively, for patients with an anti-HBs titer of 10-100 IU/I, >100-1000 IU/I and >1000 IU/I at primary vaccination. An undetectable HIV-RNA load and use of HAART during vaccination and at follow-up were, though not significantly, associated a higher long-term persistence of an effective antibody titer.

The durability of an effective anti-HBs level appears to be significantly related to the height of the antibody titers after the primary immunization procedure. Schedules to improve the vaccination response in HIV-infected patients therefore seem to be justified. Whether a HBV booster is indicated remains to be elucidated.