Last updated 7/21/25
Some individuals who initiate antiretroviral therapy (ART) experience limited recovery of CD4 T cell numbers despite suppression of HIV viral load to undetectable levels. The most common risk factors for this type of discordant response to ART are low CD4 T cell count at the time of starting and older age. Individuals in this situation still experience a benefit from ART in terms of a greatly reduced risk of opportunistic infections, illness and death, but their risk of these outcomes is higher than among people with greater CD4 T cell gains (for additional background see the webinar hosted by TAG on November 29, 2017, our March 2018 Issue Brief, and a scientific review published on February 17, 2021.)
A number of clinical trials are investigating approaches that might boost CD4 T cell recovery in individuals whose CD4 T cell counts remain relatively low despite viral load suppression. The purpose of this page is to provide a resource listing of these clinical trials, which will be updated on an ongoing basis.
Complete information on the trials is available from clinicaltrials.gov by clicking on the study title link.
Zinc Supplementation in HIV Immunological Non Responders (VIHZn)
Parc de Salut Mar, Barcelona, Spain
Age >18yrs, HIV viral load <50 copies/mL (transient blips allowed), CD4 cell count <500 or an increase of <80 cells after one year of viral load undetectability, serum zinc levels less than 150ug/dl
Impact of NMN Supplementation on CD4+ T Cell Recovery in HIV Patients With Immunological Failure
TriHealth Inc., Cincinnati, Ohio
Age >18yrs, suppressed HIV viral load, CD4 cell count <350 cells two years after effective ART initiation
Mesenchymal Stem Cells for Immune Non-responder Patients With HIV Infection
Shandong Public Health Clinical Center, Shandong, China
CD4 count <200 for people on ART for more than one year but less than two years
CD4 count <350 for people receiving ART for ≥2 years
On ART for at least one year, viral load <50 copies/mL during the last two years
ART regimen not changed in the 12 months prior to enrollment
Changes in Immunologic Parameters Following the Addition of Fostemsavir in Virologically Suppressed Immunologic Non-responders Living With HIV – the RECOVER Study
Orlando Immunology Center, Florida, United States
CD4 cell count<350 cells while on ART for at least 2 years, two viral load measurements <50 copies/mL within the last year prior to screening
Stable ART regimen for ≥6 months prior to screening
Stable insurance plan