SARS-CoV-2 mRNA vaccination and short-term changes in viral load and CD4/CD8 T-cell counts in people living with HIV

Objectives: to investigate whether SARS-CoV-2 messenger RNA (mRNA) vaccination has an impact on HIV-related viro-immunological parameters. Methods: people with HIV (PWH) in the VAXICONA-ORCHESTRA cohort who received one or more doses of SARS-CoV-2 mRNA vaccine and for whom paired measures of immuno-virological markers (viral load, clusters of differentiation [CD]4, and CD8 count 1 month before and after a vaccine dose [VD]) were available were included. Paired t -test and generalized estimating equation linear regression analyses were used to study changes over +/- 1 month around the VD. Subgroup analyses were performed. Results: a total of 510 PWH were enrolled: the median age was 55 years (interquartile range 46-60 years), the CD4 and CD8 count were 489 (287-719) and 790 (59-1104) cells/mm3, respectively, and 81% received three VDs. After a median of 28 (3-53) days from VD, CD4 count increased by + 15 cells/mm3 (SD +/- 129.7, P = 0.001) and CD8 by + 12 ( +/- 250.5, P = 0.199) and the viral load decreased by -0.11 log10 ( +/- 0.88, P = 0.001). Similar results were observed after restricting the analysis to viro-suppressed PWH, with CD4 <= 200/mm3, more than 6 months of antiretroviral therapy before VD and after excluding previous COVID-19. Conclusions: a small significant increase in CD4 count and a negligible drop in HIV RNA were observed. Our findings are consistent with the hypothesis that SARS-CoV-2 mRNA vaccine can prime CD4 T spikespecific cells, even in the more immuno-compromised PWH.