Despite the success of antiretroviral therapy (ART) in treating HIV, antigen specific memory to vaccinations that occurred before infection does not recover, even after immune reconstitution, according to study published in the Journal of Infectious Diseases. The authors also observed a decline in pre-existing antibody response.

Approximately two-thirds of patients who are HIV-positive in the United States are on an ART regimen, which works by reducing viral replication and boosting CD4 T cell counts. This process is vital to suppressing or regulating the immune response: a memory that allows immune cells to recognize and respond in large numbers when exposed to viruses, according to the study authors.

Researchers at SUNY Downstate Health Sciences University and Oregon Health & Science University suggest that this memory is inhibited in certain patients who are HIV-positive and are otherwise doing well in therapy. HIV-immune associated amnesia may have significant implications for the health status of patients with HIV, should it exist for other pre-infection vaccinations or viruses, according to the study authors.

HIV-immune associated amnesia may provide an explanation for chronic inflammation and accelerated aging observed among patients with HIV, according to the study authors. There also may be a loss of protective immunity and an increased risk for common acute or chronic viral infections among patients with HIV, regardless of whether they are on an ART regimen. Finally, there may be a potential loss of protection against common childhood diseases, such as measles, mumps, chickenpox, and pertussis.

The study suggests 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. Patients are potentially susceptible not only to these serious diseases, but also chronic infections and chronic inflammation.

The study authors caution that, although this study only examined immunologic responses to smallpox vaccination rather than specific clinical outcomes, it builds on previous studies and evidence pointing to HIV-associated immune amnesia. The study also may contribute to gathering support for earlier aggressive treatment in patients who are infected with HIV before they suffer significant damage to their immune system.

Additional studies are needed both on men who are HIV-positive using the smallpox vaccine antigen and antigens of other common diseases for which patients are vaccinated as children. The potential need for revaccination of patients, although suggested by these data, was not directly addressed by the study.

Reference
New Study Suggests Antiretroviral Therapy Does Not Restore Disease Immunity Among Previously Immunized HIV Patients [press release]. Brooklyn, NY. SUNY Downstate Health Sciences University website. Published January 6, 2020. https://www.downstate.edu/news_releases/2020/01-06-2020.html. Accessed January 14, 2020.