This is a summary, written by members of the CITF Secretariat, of:

Alexandrova Y, Yero A, Mboumba Bouassa R-S, Comeau E, Samarani S, Brumme ZL, Hull M, Crawley AM, Langlois M-A, Angel JB, Cooper CL, Needham J, Lee T, Singer J, Anis AH, Costiniuk CT, Jenabian M-A. SARS-CoV-2 Vaccine-Induced T-Cell Response after Three Doses in People Living with HIV on Antiretroviral Therapy Compared to Seronegative Controls (CTN 328 COVAXHIV Study). Viruses. February 2023. DOI: 10.3390/v15020575

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

In a peer-reviewed paper published in Viruses, a CITF-funded  study led by Dr Mohammad-Ali Jenabian (Université du Québec à Montréal, UQAM), along with Dr. Aslam Anis (University of British Columbia) found that a third dose of COVID-19 vaccines induced robust cellular immune responses in people living with HIV that are comparable to what is observed in individuals without HIV.

Key messages:

  • In people living with HIV (PLWH), the CD4 and CD8 T-cellCD4 and CD8 are two markers that can be found on the surface of T cells. Overall, CD4 T cells, also called “helpers”, help coordinate the immune response by interacting and activating other cells in the immune system. On the other hand, CD8 T cells, also called “killers”, directly attack pathogens by secreting toxic molecules. immune responses against SARS-CoV-2 increased following a second dose of COVID-19 vaccine and was maintained after a third dose.
  • After the third dose, the proportion of polyfunctional T cells Polyfunctional helper T cells produce at least 3 different types of cytokines. Helper T cells mediate the immune response through the production of small molecules called cytokines. producing tumor necrosis factor (TNF)-α / interferon(IFN)-γ / interleukin(IL)-2 was similar between PLWH and individuals without HIV.
  • Similarly, the amount of anti-SARS-CoV-2 “killer” T cells increased in PLWH after the second dose and remained unchanged after the third dose.
  • Changes in some T cell subsets were observed following a third dose when comparing PLWH and non-HIV infected controls.

This study followed 38 PLWH on antiretroviral therapy and 24 seronegative individuals (who were never infected by SARS-CoV-2) without HIV. Blood from PLWH was collected before vaccination and after the first, second and third vaccine doses, while only pre-vaccination and post-third dose blood samples were collected from the controls.

Previous studies by the CTN 328 COVAXHIV Study team showed that PLWH mounted vaccine-induced antibody responses similar to that of individuals without HIV. See summaries of their previous work on the CITF website here and here.