COVID-19, SARS-CoV-2 Vaccination, and Human Herpesviruses Infections

Lack of Specific Immune Response after Five Doses of mRNA SARS-CoV-2 Vaccine in a Patient with CD4+ T-Cell Lymphopenia but Preserved Responses to CMV

Immunogenicity of SARS-CoV-2 mRNA vaccines is highly heterogeneous in patients with inborn errors of immunity (IEIs). This case report analyzes the immune response to mRNA COVID-19 two-dose primary vaccination followed by three boosters in an IEI patient with marked CD4+ T-cell cytopenia and diminished thymic output, in comparison with that raised against latent, chronic cytomegalovirus (CMV) infection. Serum IgG antibodies anti-spike (S) protein of SARS-CoV-2 and anti-CMV were both determined by chemiluminescent microparticle immunoassays (CMIAs). SARS-CoV-2 and CMV memory CD4+ T-cell responses were simultaneously evaluated in vitro using an activation-induced marker (AIM) assay via multicolor flow cytometry. Throughout the 2-year follow-up that included the administration of five doses of SARS-CoV-2 mRNA vaccines, cellular anti-SARS-CoV-2-specific responses remained consistently negative, with extremely weak humoral responses, while the patient showed in vitro persistent CD4+ T-cell reactivity to CMV peptides and high-IgG CMV-specific titers. The assessment of immune responses to vaccines and prevalent viruses is essential in IEI patients in order to take adequate preventive measures.

Visual analysis of hotspots and trends in long COVID research based on bibliometric

After severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, a series of symptoms may persist for a long time, which is now called long COVID. It was found that long COVID can affect all patients with COVID-19. Therefore, long COVID has become a hot topic. In this study, we used the WOS database as a sample data source to conduct a bibliometric and visual analysis of 1765 long COVID articles over the past three years through VOSviewer and R package. The results show that countries/authors in Europe and The United States of America contribute most of the articles, and their cooperation is also the most active. Keyword co-occurrence identified four clusters, with important topics including the mechanism, clinical symptoms, epidemiological characteristics, and management/treatment of long COVID. Themes such as "cognitive impairment", "endothelial dysfunction", "diagnosis", and "biomarkers" are likely to be the focus of new attention in the coming period. In addition, we put forward the possible research opportunities on long COVID for researchers and practitioners to facilitate future research.

The impact of BNT162b2 mRNA vaccine on adaptive and innate immune responses

The mRNA-based BNT162b2 protects against severe disease and mortality caused by SARS-CoV-2 via induction of specific antibody and T-cell responses. Much less is known about its broad effects on immune responses against other pathogens. Here, we investigated the adaptive immune responses induced by BNT162b2 vaccination against various SARS-CoV-2 variants and its effects on the responsiveness of immune cells upon stimulation with heterologous stimuli. BNT162b2 vaccination induced effective humoral and cellular immunity against SARS-CoV-2 that started to wane after six months. We also observed long-term transcriptional changes in immune cells after vaccination. Additionally, vaccination with BNT162b2 modulated innate immune responses as measured by inflammatory cytokine production after stimulation - higher IL-1/IL-6 release and decreased IFN-α production. Altogether, these data expand our knowledge regarding the overall immunological effects of this new class of vaccines and underline the need for additional studies to elucidate their effects on both innate and adaptive immune responses.

SARS-CoV-2 Induced Herpes Virus Reactivations and Related Implications in Oncohematology: When Lymphocytopenia Sets in and Immunosurveillance Drops Out

The severe acute respiratory syndrome, coronavirus 2 (SARS-CoV-2), is a positive-sense single-stranded ribonucleic acid (RNA) virus contagious in humans and responsible for the ongoing coronavirus disease 2019 (COVID-19) [...].

Cardiovascular and haematological pathology in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A role for viruses

ME/CFS is a debilitating chronic condition that often develops after viral or bacterial infection. Insight from the study of Long COVID/Post Acute Sequelae of COVID-19 (PASC), the post-viral syndrome associated with SARS-CoV-2 infection, might prove to be useful for understanding pathophysiological mechanisms of ME/CFS. Disease presentation is similar between the two conditions, and a subset of Long COVID patients meet the diagnostic criteria for ME/CFS. Since Long COVID is characterized by significant vascular pathology - including endothelial dysfunction, coagulopathy, and vascular dysregulation - the question of whether or not the same biological abnormalities are of significance in ME/CFS arises. Cardiac abnormalities have for a while now been documented in ME/CFS cohorts, with recent studies demonstrating major deficits in cerebral blood flow, and hence vascular dysregulation. A growing body of research is demonstrating that ME/CFS is accompanied by platelet hyperactivation, anomalous clotting, a procoagulant phenotype, and endothelial dysfunction. Endothelial damage and dysregulated clotting can impair substance exchange between blood and tissues, and result in hypoperfusion, which may contribute to the manifestation of certain ME/CFS symptoms. Here we review the ME/CFS literature to summarize cardiovascular and haematological findings documented in patients with the condition, and, in this context, briefly discuss the potential role of previously-implicated pathogens. Overall, cardiac and haematological abnormalities are present within ME/CFS cohorts. While atherosclerotic heart disease is not significantly associated with ME/CFS, suboptimal cardiovascular function defined by reduced cardiac output, impaired cerebral blood flow, and vascular dysregulation are, and these abnormalities do not appear to be influenced by deconditioning. Rather, these cardiac abnormalities may result from dysfunction in the (autonomic) nervous system. Plenty of recently published studies are demonstrating significant platelet hyperactivity and endothelial dysfunction in ME/CFS, as well as anomalous clotting processes. It is of particular importance to determine to what extent these cardiovascular and haematological abnormalities contribute to symptom severity, and if these two systems can be targeted for therapeutic purposes. Viral reservoirs of herpesviruses exist in ME/CFS, and most likely contribute to cardiovascular and haematological dysfunction directly or indirectly. This review highlights the potential of studying cardiac functioning, the vasculature, and coagulation system in ME/CFS.