Immune Memory to Vaccinations and Infections before HIV Infection May Not be Reconstituted
Following Successful Anti-Retroviral Therapy
Michael Augenbraun, M.D.
Professor of Medicine and Chief of Infectious Diseases
A study led by CTSC authorized user, Dr. Michael Augenbraun and colleagues at SUNY
Downstate Health Sciences University and collaborators at Oregon Health & Science
University showed that, despite successful antiretroviral therapy (ART), antigen specific
memory to vaccinations that occurred before HIV infection did not recover, even after
immune reconstitution. Additionally, a previously unrealized decline in pre-existing
antibody response was also observed.
Approximately two-thirds of HIV-positive patients in the U.S. are on an ART regimen.
It works by reducing viral replication and boosting CD4 T cell counts, which are important
to suppressing or regulating the immune response. Normally, these cells “remember”
viruses and respond in large numbers when exposed again.
However, according to Dr. Augenbraun and colleagues, this study suggests that this
memory is inhibited in some HIV-positive patients who are otherwise doing well on
therapy. Should this loss of serological memory, or HIV-immune associated amnesia,
exist for other pre-infection vaccinations or viruses, it would have significant implications
for the overall health status of HIV patients, including:
- Providing an explanation for chronic inflammation and “accelerated aging” observed
among people with HIV
- Suggesting a loss of protective immunity and an increased risk for common acute or
chronic viral infections among people with HIV, regardless of whether they are on
an ART regimen
- Suggesting a potential loss of protection against such common childhood diseases such
as measles, mumps, chickenpox, pertussis (whooping cough) and others, for which these
patients were previously vaccinated as children, prior to HIV infection, and not restored
by ART
“There is no doubt that ART provides significant, life-changing benefits for people
with HIV by reconstituting their overall immune response,” said Michael Augenbraun,
MD, FACP. FIDSA, Professor of Medicine and Vice Chair, Department of Medicine and
Director, Division of Infectious Diseases at SUNY Downstate Health Sciences University
and Kings County Hospital Center.
“What our study suggests is that ART may not be completely effective in restoring
the immune protection resulting from viral infections or childhood vaccines received
prior to becoming HIV positive,” added Dr. Augenbraun. “This makes these patients
potentially susceptible not only to these serious diseases, but also other chronic
infections and to chronic inflammation that may diminish their overall health and
shorten their lifespan.”
Dr. Augenbraun cautions that, while this study only examined immunologic responses
to smallpox vaccination and not to specific clinical outcomes, it builds on previous
studies and evidence pointing to HIV-associated immune amnesia. He says additional
studies need to be conducted both on HIV positive men utilizing the smallpox vaccine
antigen, and antigens of other common diseases for which people are vaccinated as
children. Additionally, Dr. Augenbraun believes the study may also contribute to gathering support for earlier
aggressive treatment in HIV infected individuals before they suffer significant damage
to their immune system.
Should future studies identify broader HIV-associated immune amnesia, it could mean
that a significant proportion of the 1.1 million people in the U.S. and more than
23 million people worldwide living with HIV have diminished protection from previous
immunizations. However, he cautioned that the potential need for revaccination of
patients, although suggested by these data, was not directly addressed by the study.
Additional information is available at Journal of Infectious Diseases,
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