HIV
and Hepatitis.com Coverage of the 14th
Annual Conference on Retroviruses and Opportunistic Infections (14th CROI) February
25 - 28, 2007, Los Angeles, CA
People
with HIV are advised to receive the hepatitis B virus (HBV) vaccine, due to overlapping
risk factors for the 2 infections. However, HIV positive people with compromised
immune function may respond poorly to vaccinations, due to impaired ability to
produce antibodies. Most studies have found HBV vaccine response rates ranging
from 30% to 60% in HIV positive patients, compared
with 90% for HIV negative individuals.
Several studies reported at the 14th Conference on
Retroviruses and Opportunistic Infections last month in Los Angeles looked at
HBV vaccination in HIV positive patients, including a trial
of a vaccine adjuvant reported previously.
Study
1
Researchers
from Erasmus Medical Center in the Netherlands conducted
a study in which they re-administered the HBV vaccine to all prior non-responders at their clinic whose HBV surface antibody (anti-HBs)
titers did not reach at least 10 IU/L after the initial vaccine series. Patients
were re-vaccinated using a double dose of the vaccine (20 µg) at monthly intervals.
Of the 135 patients who were re-vaccinated, 57.8% responded, achieving
the target anti-HBs level. Predictors of successful response were younger age,
female sex, and undetectable HIV viral load. Link to
study abstract and PDF
of poster
Study 2
The
second study, conducted in Dublin, Ireland, looked at factors associated with
successful HBV vaccination in people with HIV. The researchers conducted an “audit” of all patients
recruited into an HBV vaccination program between January 2003 and December 2005,
determining whether they successfully completed
the vaccination process. Vaccine failures included both patients who did not return
to receive the full series of 3 injections and those who did not achieve target
antibody titers despite competing the
series.
In 2005, the program began
providing double doses of the HBV vaccine to HIV positive prior non-responders.
It also instituted a text messaging service to remind patients to return for subsequent
appointments to complete the series
of injections.
Overall, 13 of the 15 patients
(87%) who were re-vaccinated with double doses achieved protective antibody titers
(HBs seroconversion) the second time around. All responding patients had CD4 cell
counts above 500 cells/mm3, while the 2 non-responders had CD4 counts
below this level.
HIV positive individuals
were more likely than HIV negative subjects to complete
the 3-shot series (75% vs 68%). Women were more likely to complete the series than men, but there was no difference
related to age. Among HIV positive individuals, men who have sex with men were
less likely to complete the series
than heterosexuals or injection drug users (IDUs), but among HIV negative subjects,
IDUs were least likely to complete
the series.
T.E.M.S.
de Vries-Sluijs, B Hansen, G van Doornum, and others. The Efficacy
of High-dose Recombinant Hepatitis
B Vaccination in HIV-infected Patients Who Failed at First Series of Vaccinations.
14th Conference
on Retroviruses and Opportunistic Infections (CROI). Los Angeles, February 25-28,
2007. Abstract 883 (poster).
S Low, A Prior, B Mooka, and others.
Strategies for Management and Optimization of Response to Hepatitis
B Vaccination in HIV Patients. 14th CROI. Abstract 884 (poster).
