Lower T cell response against SARS-CoV-2 variants of concern after mRNA vaccine and risk of breakthrough infections in people with HIV

SIV/SARS-CoV-2 co-infection in rhesus macaques impacts viral shedding, host immunity, the microbiome, and viral evolution

People living with HIV (PLWH) have an increased risk of severe COVID-19, including prolonged viral shedding and emergence of mutations. To investigate the simian immunodeficiency virus (SIV) macaque model for HIV/SARS-CoV-2 co-infection, seven SIV+ rhesus macaques were co-infected with SARS-CoV-2. COVID-19 in all macaques was mild. SARS-CoV-2 replication persisted in the upper, but not the lower respiratory tract for 14 days post-infection. Animals showed impaired generation of anti-SARS-CoV-2 antibodies and T-cells. Animals also displayed transient changes in microbial communities in the upper airway and gastrointestinal tract. Evidence of SARS-CoV-2 evolution was observed in the upper respiratory tract. This study demonstrates that SIV/SARS-CoV-2 co-infection in rhesus macaques recapitulates aspects of COVID-19 in PLWH. We show that SIV impairs anti-SARS-CoV-2 immunity, potentially leading to prolonged viral shedding, altered pathogenesis, and viral evolution. This highlights the importance of HIV status in COVID-19 and supports the use of this model for HIV/SARS-CoV-2 co-infection.

The characterization of CD8+ T-cell responses in COVID-19

This review gives an overview of the protective role of CD8+ T cells in SARS-CoV-2 infection. The cross-reactive responses intermediated by CD8+ T cells in unexposed cohorts are described. Additionally, the relevance of resident CD8+ T cells in the upper and lower airway during infection and CD8+ T-cell responses following vaccination are discussed, including recent worrisome breakthrough infections and variants of concerns (VOCs). Lastly, we explain the correlation between CD8+ T cells and COVID-19 severity. This review aids in a deeper comprehension of the association between CD8+ T cells and SARS-CoV-2 and broadens a vision for future exploration.

When Cell-Mediated Immunity after Vaccination Is Important

The review by Reeg D [...].

SARS-CoV-2 vaccine immunogenicity for people living with HIV: A systematic review and meta-analysis

BACKGROUND

Previous publications on the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in people living with HIV (PLWH) have reported inconsistent results. Additionally, a meta-analysis investigating the immunogenicity in PLWH after the third SARS-CoV-2 vaccine dose is lacking. In this article we aim to provide a systematic review and a meta-analysis studying the immunogenicity of SARS-CoV-2 vaccines in PLWH and to identify potential drivers for antibody response in PLWH.

METHODS

We used three databases (PubMed, Embase and Web of Science) to conduct our review. Studies with information on numbers of PLWH producing immunoglobulin G (IgG) antibodies or neutralizing antibodies were included.

RESULTS

The meta-analysis included 59 studies and illustrated a pooled serological response of 87.09% in the 10 343 PLWH after they received a SARS-CoV-2 vaccine. High CD4 T-cell counts and low viral load indicated that the study populations had HIV that was well treated, despite varying in location. The pooled effect increased to 91.62% for 8053 PLWH when excluding studies that used inactivated vaccines (BBIBP-CorV and CoronaVac). For the third vaccine dose, the pooled effect was 92.35% for 1974 PLWH. Additionally, weighted linear regression models demonstrated weak relationships between CD4 T-cell count, percentages of people with undetectable HIV load, and age compared with the percentages of PLWH producing a serological response. However, more research is needed to determine the effect of those factors on SARS-CoV-2 vaccine immunogenicity in PLWH.

CONCLUSION

SARS-CoV-2 vaccines show a favourable effect on immunogenicity in PLWH. However, the results are not ideal. This meta-analysis suggests that a third SARS-CoV-2 vaccine dose and good HIV treatment procedures are vital to induce a good immunogenicity in PLWH.