Hepatitis
A Vaccine Response Durable in People with HIV
SUMMARY
People with well-controlled HIV infection respond well to
hepatitis A vaccination, with 89% achieving an initial response
and 85% still protected after 6-10 years. |
By
Liz Highleyman
Hepatitis
A virus (HAV) can cause more aggressive liver disease in people
with HIV, and experts recommend
that individuals who are diagnosed as HIV positive should be vaccinated
against hepatitis A and B (there currently is no effective hepatitis
C vaccine).
As
described in the June
2011 Journal of Infectious Diseases, Nancy Crum-Cianflone
and fellow investigators with the Infectious Disease Clinical
Research Program HIV Working Group looked at durability of HAV
vaccine protection in the HIV positive population.
This
retrospective analysis included 130 HIV positive adults in the
U.S. Military HIV Natural History Study; most were men and the
median age was 35 years. The median CD4 cell was quite high, at
461 cells/mm3 (near the threshold for starting antiretroviral
treatment according to current U.S. guidelines), and about half
had HIV RNA viral load < 1000 copies/mL; 62% were taking antiretroviral
therapy (ART).
All
participants received the standard 2 doses of HAV vaccine. The
researchers analyzed blood specimens collected at 1 year, 3 years,
and, if available, 6 to 10 years after vaccination. HAV immunoglobulin
G (IgG) antibody levels of 10 mIU/mL or greater were considered
protective.
Results
 |
89%
of HIV positive participants achieved initial vaccine responses,
compared with 100% of HIV negative historical controls (that
is, results seen in prior studies). |
|
Among
HIV positive initial responders with available follow-up specimens,
longer-term response rates remained high: |
| |
 |
89%
protection at 1 year; |
|
90%
still HAV antibody positive after 3 years; |
|
85%
still protected after 6 to 10 years. |
|
|
However,
average HAV antibody concentrations were lower in HIV positive
people compared with HIV negative controls: |
|
|
1
year: 154 vs 1734 mIU/mL, respectively; |
|
3
years: 111 vs 687 mIU/mL, respectively; |
|
6-10
years: 64 vs 684 mIU/mL, respectively; |
|
|
People
with CD4 cell counts > 350 cells/mm3 when vaccinated were
more likely to achieve an initial response than those with
lower levels (94% vs 78%, respectively), but this was no longer
statistically significant at 3 years. |
|
Over
time, among HIV participants, higher HAV antibody levels were
significantly associated with low HIV viral load. |
Based
on these findings, the investigators concluded, "Most adults
with well-controlled HIV infections had durable seropositive responses
up to 6-10 years after HAV vaccination."
"[M]aintaining suppressed HIV RNA levels among HIV-infected
persons may be an important strategy for sustaining durable antibody
levels for vaccine preventable infections such as hepatitis A
virus," they suggested.
Investigator affiliations: Infectious Disease Clinical Research
Program, Uniformed Services University of the Health Sciences,
Bethesda, MD; Infectious Disease Clinic, Naval Medical Center
San Diego, CA; Merck Research Laboratories, North Wales, PA; Infectious
Disease Service, San Antonio Military Medical Center, TX; Infectious
Disease Clinic, Walter Reed Army Medical Center, Washington, DC;
Infectious Disease Clinic, National Naval Medical Center, Bethesda,
MD; Infectious Disease Clinic, Naval Medical Center Portsmouth,
VA; Infectious Disease Clinic, Orlando Regional Medical Clinic,
FL.
7/8/11
Reference
NF Crum-Cianflone, K Wilkins, AW Lee, et al (Infectious Disease
Clinical Research Program HIV Working Group). Long-term Durability
of Immune Responses After Hepatitis A Vaccination Among HIV-Infected
Adults. Journal of Infectious Diseases 203(12):1815-1823.
