Impaired humoral immunity is associated with prolonged COVID-19 despite robust CD8 T cell responses

The contributions of T cell-mediated immunity to protection from vaccine-preventable diseases: A primer

In the face of the ever-present burden of emerging and reemerging infectious diseases, there is a growing need to comprehensively assess individual- and population-level immunity to vaccine-preventable diseases (VPDs). Many of these efforts, however, focus exclusively on antibody-mediated immunity, ignoring the role of T cells. Aimed at clinicians, public health practioners, and others who play central roles in human vaccine research but do not have formal training in immunology, we review how vaccines against infectious diseases elicit T cell responses, what types of vaccines elicit T cell responses, and how T cell responses are measured. We then use examples to demonstrate six ways that T cells contribute to protection from VPD, including directly mediating protection, enabling antibody responses, reducing disease severity, increasing cross-reactivity, improving durability, and protecting special populations. We conclude with a discussion of challenges and solutions to more widespread consideration of T cell responses in clinical vaccinology.

Long-Term Outcomes of COVID-19 and Risk Factors for Prolonged or Persistent COVID-19 in Lymphoma Patients: A Multicenter, Retrospective Cohort Study

BACKGROUND

Patients with hematologic malignancies exhibit persistent severe acute respiratory syndrome coronavirus 2 positivity over long periods after coronavirus disease 2019 (COVID-19) diagnosis. However, the frequency of, risk factors for, and prognosis of prolonged COVID-19 in immunocompromised patients remain unclear. Therefore, we investigated the long-term outcomes of COVID-19 in lymphoma patients and identified the associated factors and impact of prolonged COVID-19 on mortality.

METHODS

A multicenter retrospective cohort study of 583 lymphoma patients was conducted in 3 tertiary hospitals in South Korea. Patients receiving lymphoma treatment who were quarantined after obtaining a diagnosis of COVID-19 by polymerase chain reaction (PCR) or antigen test from August 2021 to September 2022 were examined.

RESULTS

Overall, 115 patients (19.7%) were diagnosed with COVID-19. Among 77 patients with clinical data, 24 had prolonged COVID-19. Patients in the prolonged COVID-19 group showed higher rates of receiving rituximab maintenance therapy following bendamustine and rituximab (BR) treatment for follicular lymphoma. This group did not show significant differences in clinical presentation within 30 days of COVID-19 diagnosis; however, it showed higher rates of re-admission due to COVID-19 pneumonia compared with the non-prolonged COVID-19 group. BR treatment followed by rituximab maintenance therapy is one of the risk factors for persistent PCR positivity, delayed or persistent pneumonia, and COVID-19 related admission after quarantine period. Prolonged COVID-19 was an independent risk factor for 1-year mortality.

CONCLUSION

Prolonged COVID-19 was more frequent in lymphoma patients who received BR treatment followed by rituximab maintenance therapy and associated with unfavorable long-term outcomes and higher 1-year mortality.

A Robust Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)-Specific T- and B-Cell Response Is Associated With Early Viral Clearance in SARS-CoV-2 Omicron-Infected Immunocompromised Individuals

BACKGROUND

The immunological determinants of delayed viral clearance and intrahost viral evolution that drive the development of new pathogenic virus strains in immunocompromised individuals are unknown. Therefore, we longitudinally studied severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immune responses in relation to viral clearance and evolution in immunocompromised individuals.

METHODS

Among Omicron-infected immunocompromised individuals, we determined SARS-CoV-2-specific T- and B-cell responses, anti-spike immunoglobulin G (IgG) and IgG3 titers, neutralization titers, and monoclonal antibody (mAb) resistance-associated mutations. The 28-day post-enrollment nasopharyngeal specimen defined early (reverse-transcription polymerase chain reaction [RT-PCR] negative ≤28 days) or late (RT-PCR positive >28 days) viral clearance.

RESULTS

Of 30 patients included (median age, 61.9 [interquartile range, 47.4-72.3] years; 50% females), 20 (66.7%) received mAb therapy. Thirteen (43.3%) demonstrated early and 17 (56.7%) late viral clearance. Patients with early viral clearance and patients without resistance-associated mutations had significantly higher baseline interferon-γ release, and patients with early viral clearance had a higher frequency of SARS-CoV-2-specific B cells at baseline. In non-mAb-treated patients, day 7 IgG and neutralization titers were significantly higher in those with early versus late viral clearance.

CONCLUSIONS

An early robust adaptive immune response is vital for efficient viral clearance and associated with less emergence of mAb resistance-associated mutations in Omicron-infected immunocompromised patients. This emphasizes the importance of early SARS-CoV-2-specific T- and B-cell responses and thereby provides a rationale for development of novel therapeutic approaches.

Single-cell mapping of peripheral blood mononuclear cells reveals key transcriptomic changes favoring coronary artery lesion in IVIG-resistant Kawasaki disease

Background

Intravenous immunoglobulin (IVIG)-resistant Kawasaki disease (KD) poses a considerable challenge to patients and their families due to its severe complications. Previous researches have highlighted the critical role of immune disorders in its pathogenesis. However, fragmented studies based on isolated cases hinder a comprehensive understanding of this deadly illness. This study aimed to explore the overall landscape of peripheral blood mononuclear cells (PBMCs) in IVIG-resistant KD patients using single-cell RNA sequencing (scRNA-seq).

Methods

The scRNA-seq was used to characterize the transcriptomic profiles of IVIG-resistant KD patients, IVIG-responsive KD patients, and healthy controls. Data quality control (QC) and subsequent analysis were conducted using various R packages. These included DoubletFinder and Harmony for QC, Seurat and SingleR for identifying and annotating major cell types, ggpubr for calculating and visualizing the percentages of each cell type, Seurat for characterizing differentially expressed genes (DEGs) between groups, pheatmap for visualizing the DEGs, clusterProfiler for performing Gene Ontology (GO) enrichment analysis of DEGs, scRepertoire for TCR and BCR data analysis, Monocle for assessing cell differentiation trajectories, and CellChat for intercellular interaction evaluation.

Results

High-quality single-cell transcriptome data from 12 participants were analyzed, including five with IVIG-resistant KD, four with IVIG-responsive KD, and three healthy controls. We identified 10 major cell types and observed that the differentiation of CD8+ effector T cells was impeded in IVIG-resistant KD patients with coronary artery lesion (CAL) according to cell differentiation trajectory analysis. Subsequent cell communication analysis demonstrated that myeloid cluster with high expression of LCN2, S100P, and LTF played a key role, potentially signaling through MIF-CD74/CXCR4 and MIF-CD74/CD44 ligand-receptor pairs.

Conclusion

Complex immunopathological changes occur during the development of CAL in IVIG-resistant KD. Stunted differentiation of CD8+ effector T cells is noted in KD-CAL. Interactions between myeloid cells and T cells activates multiple inflammatory signaling pathways, with ligand-receptor pairs, including MIF-CD74/CXCR4 and MIF-CD74/CD44, potentially playing crucial roles.

A Brighton Collaboration standardized template with key considerations for a benefit-risk assessment for the Comirnaty COVID-19 mRNA vaccine

The Brighton Collaboration Benefit-Risk Assessment of VAccines by TechnolOgy (BRAVATO) Working Group evaluates the safety and other key features of new platform technology vaccines, including nucleic acid (RNA and DNA) vaccines. This manuscript uses the BRAVATO template to report the key considerations for a benefit-risk assessment of the coronavirus disease 2019 (COVID-19) mRNA-based vaccine BNT162b2 (Comirnaty®, or Pfizer-BioNTech COVID-19 vaccine) including the subsequent Original/Omicron BA.1, Original/Omicron BA.4-5 and Omicron XBB.1.5 variant-adapted vaccines developed by BioNTech and Pfizer to protect against COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Initial Emergency Use Authorizations or conditional Marketing Authorizations for the original BNT162b2 vaccine were granted based upon a favorable benefit-risk assessment taking into account clinical safety, immunogenicity, and efficacy data, which was subsequently reconfirmed for younger age groups, and by real world evidence data. In addition, the favorable benefit-risk assessment was maintained for the bivalent vaccines, developed against newly arising SARS-CoV-2 variants, with accumulating clinical trial data.

Treatment of chronic COVID-19 with convalescent/postvaccination plasma in patients with hematologic malignancies

Immunocompromised patients are at high risk to fail clearance of SARS-CoV-2. Prolonged COVID-19 constitutes a health risk and a management problem as cancer treatments often have to be disrupted. As SARS-CoV-2 evolves, new variants of concern have emerged that evade available monoclonal antibodies. Moreover, antiviral therapy promotes SARS-CoV-2 escape mutations, particularly in immunocompromised patients. These patients frequently suffer from prolonged infection. No successful treatment has been established for persistent COVID-19 infection. Here, we report on a series of 21 immunocompromised patients with COVID-19-most of them hematologic malignancies-treated with plasma obtained from recently convalescent or vaccinated donors or a combination thereof. Repeated dosing of SARS-CoV-2-antibody-containing plasma could clear SARS-CoV-2 infection in 16 out of 21 immunocompromised patients even if COVID-19-specific treatments failed to induce sustained viral clearance or to improve clinical course of SARS-CoV-2 infection. Ten patients were major responders defined as an increase delta(d)Ct of > = 5 after the first administration of convalescent and/or vaccinated plasma (C/VP). On average, SARS-CoV-2 PCR Ct values increased from a median value of 22.55 (IQR = 19.10-24.25) to a median value of 29.57 (IQR = 27.55-34.63; p = <.0001) in the major response subgroup. Furthermore, when treated a second time with C/VP, even 4 out of 5 of the initial nonresponders showed an increase in Ct-values from a median value of 23.13 (IQR = 17.75-28.05) to a median value of 32.79 (IQR = 31.75-33.75; p = .013). Our results suggest that C/VP could be a feasible treatment of COVID-19 infection in patients with hematologic malignancies who did not respond to antiviral treatment.

Immunophenotype of lymphocytes and real-world outcome of COVID-19 infection in children with hematology and oncology

BACKGROUND

Patients with immunocompromise were suspected to encounter a high risk for severe coronavirus disease 2019 (COVID-19) infection on early period; however, data is lacking nowadays and immune response remain unclear.

METHODS

In this retrospective study, internet questionnaire survey and medical records were acquired in pediatric hematology oncology patients. Clinical severity, immunological characteristics, and outcomes were analyzed from December 1, 2022 to January 31, 2023 at the 3rd year of pandemic in China.

RESULTS

A total of 306 patients were included, with 21 patients (6.9%) asymptomatic, 262 (85.6%) mild severity, 17 (5.6%) moderate severity, 5 (1.6%) severe severity, and 1 (0.3%) critical severity. Seventy-eight (25.5%) patients were on intensive chemotherapy, and 32.0% children were on maintenance chemotherapy. Delays in cancer therapy occurred in 86.7% patients. Univariable analysis revealed active chemotherapy (P < 0.0001), long duration of symptom (P < 0.0001), low lymphocytes count (P = 0.095), low CD3 + and CD8 + T cell count (P = 0.013, P = 0.022), high percentage of CD4 + TCM (P = 0.016), and low percentage of transitional B cells (P = 0.045) were high risk factors for severe COVID-19 infection. Cox regression model showed that the absolute lymphocytes count (P = 0.027) and long duration of symptom (P = 0.002) were the independent factors for severity. Patients with CD8 + dominant and B cell depletion subtype wasn't related with severity, but had higher percentage of CD8 + effector memory T cells (TEM) and terminally differentiated effector memory T cells (TEMRA) (P < 0.001, P < 0.001), and a longer COVID-19 duration (P = 0.045).

CONCLUSION

The severity was relatively mild in children with immunodeficiencies in the third year of COVID-19 pandemic. Low lymphocyte count and long duration of symptom were the independent risk factors with COVID-19 severity. Delays in cancer care remain a major concern and the long outcome is pending.

Prolonged viral pneumonia and high mortality in COVID-19 patients on anti-CD20 monoclonal antibody therapy

PURPOSE

In clinical practice, we observed an apparent overrepresentation of COVID-19 patients on anti-CD20 monoclonal antibody therapy. The aim of this study was to characterize the clinical picture of COVID-19 in these patients.

METHODS

All adult patients from Turku University Hospital, Turku, Finland, with COVID-19 diagnosis and/or positive SARS-CoV-2 PCR test result up to March 2023, and with anti-CD20 therapy within 12 months before COVID-19 were included. Data was retrospectively obtained from electronic patient records.

RESULTS

Ninety-eight patients were identified. 44/93 patients (47.3%) were hospitalized due to COVID-19. Patients with demyelinating disorder (n = 20) were youngest (median age 36.5 years, interquartile range 33-45 years), had less comorbidities, and were least likely to be hospitalized (2/20; 10.0%) or die (n = 0). COVID-19 mortality was 13.3% in the whole group, with age and male sex as independent risk factors. Persistent symptoms were documented in 33/94 patients (35.1%) alive by day 30, in 21/89 patients (23.6%) after 60 days, and in 15/85 after 90 days (17.6%), mostly in patients with haematological malignancy or connective tissue disease. Prolonged symptoms after 60 days predisposed to persistent radiological findings (odds ratio 64.0; 95% confidence interval 6.3-711; p < 0.0001) and persistently positive PCR (odds ratio 45.5, 95% confidence interval 4.0-535; p < 0.0001). Several patients displayed rapid response to late antiviral therapy.

CONCLUSION

Anti-CD20 monoclonal antibody therapy is associated with high COVID-19 mortality and with a phenotype consistent with prolonged viral pneumonia. Our study provides rationale for retesting of immunocompromised patients with prolonged COVID-19 symptoms and considering antiviral therapy.

Efficacy and safety of antiviral plus anti-spike monoclonal antibody combination therapy vs. monotherapy for high-risk immunocompromised patients with mild-to-moderate SARS-CoV2 infection during the Omicron era: A prospective cohort study

INTRODUCTION

Antivirals and monoclonal antibodies lower the risk of progression in immunocompromised patients. However, combination therapy with both types of agents has not been studied.

PATIENTS AND METHODS

This was a single-centre, prospective, cohort study. All immunocompromised patients who received treatment for mild-to-moderate COVID-19 from 1 January 2022 to 30 October 2022 were enrolled. The primary endpoint was COVID-19 progression at 90 days, defined as hospital admission or death due to COVID-19 and/or seronegative persistent COVID-19.

RESULTS

A total of 304 patients were included: 43 patients (14.1%) received sotrovimab plus a direct-acting antiviral, and 261 (85.9%) received monotherapy. Primary outcome occurred more frequently after monotherapy (4.6% vs. 0%, P=0.154). Among patients with anti-spike immunoglobulin G (anti-S IgG) titre <750 BAU/mL, COVID-19 progression was more common after monotherapy (23.9% vs. 0%, P=0.001), including more frequent COVID-related admission (15.2% vs. 0%, P=0.014) and seronegative persistent COVID-19 (10.9% vs. 0%, P=0.044). Combination therapy was associated with lower risk of progression (odds ratio [OR] 0.08, 95% confidence interval [95% CI] 0.01-0.64). Anti-S IgG titre <750 BAU/mL and previous anti-CD20 were associated with higher risk of progression (OR 13.70, 95% CI 2.77-67.68; and OR 3.05, 95% CI 1.20-10.94, respectively).

CONCLUSIONS

In immunocompromised patients, combination therapy with sotrovimab plus an antiviral may be more effective than monotherapy for SARS-CoV2.

Coronavirus Disease-2019 in the Immunocompromised Host

Immunocompromised hosts, which encompass a diverse population of persons with malignancies, human immunodeficiency virus disease, solid organ, and hematologic transplants, autoimmune diseases, and primary immunodeficiencies, bear a significant burden of the morbidity and mortality due to coronavirus disease-2019 (COVID-19). Immunocompromised patients who develop COVID-19 have a more severe illness, higher hospitalization rates, and higher mortality rates than immunocompetent patients. There are no well-defined treatment strategies that are specific to immunocompromised patients and vaccines, monoclonal antibodies, and convalescent plasma are variably effective. This review focuses on the specific impact of COVID-19 in immunocompromised patients and the gaps in knowledge that require further study.

The role of SARS-CoV-2 nucleocapsid protein in antiviral immunity and vaccine development

ABSTRACTThe coronavirus disease 2019 (COVID-19) has caused enormous health risks and global economic disruption. This disease is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 nucleocapsid protein is a structural protein involved in viral replication and assembly. There is accumulating evidence indicating that the nucleocapsid protein is multi-functional, playing a key role in the pathogenesis of COVID-19 and antiviral immunity against SARS-CoV-2. Here, we summarize its potential application in the prevention of COVID-19, which is based on its role in inflammation, cell death, antiviral innate immunity, and antiviral adaptive immunity.

Clinical experience in the treatment of COVID-19 with monoclonal antibodies in solid organ transplant recipients

Solid organ transplant (SOT) recipients are at high risk for complications from coronavirus disease 2019 (COVID-19). SOT recipients mount lower immunological responses to vaccines than general population and are at high risk for breakthrough COVID-19 infections. Passive immunotherapy in the form of anti-Spike monoclonal antibodies (MoAbs) may be an alternative for the prophylaxis and treatment of COVID-19 in these patients. SARS-CoV-2 has evolved by accumulating resistance mutations that have escaped the neutralizing action of most MoAbs. However, MoAbs directed at more conserved epitopes and that maintain effector functions could maintain efficacy in the treatment of these patients. According to published data, SOT recipients with low anti-spike antibody responses to vaccination could benefit from the use of MoAbs in pre-exposure prophylaxis, in the treatment of COVID-19 mild to moderate and severe COVID-19 with less than 15 days of symptom duration and low oxygen requirements. Combination therapy could be more effective than monotherapy for the treatment of mild-to-moderate SARS-CoV-2 infection.

Predictive factors of delayed viral clearance of asymptomatic Omicron-related COVID-19 screened positive in patients with cancer receiving active anticancer treatment

OBJECTIVES

We sought to identify the predictors of delayed viral clearance in patients with cancer with asymptomatic COVID-19 when the SARS-CoV-2 Omicron variants prevailed in Hong Kong.

METHODS

All patients with cancer who were attending radiation therapy for head and neck malignancies or systemic anticancer therapy saved their deep throat saliva or nasopharyngeal swabs at least twice weekly for SARS-CoV-2 screening between January 1 and April 30, 2022. The multivariate analyses identified predictors of delayed viral clearance (or slow recovery), defined as >21 days for the cycle threshold values rising to ≥30 or undetectable in two consecutive samples saved within 72 hours. Three machine learning algorithms evaluated the prediction performance of the predictors.

RESULTS

A total of 200 (15%) of 1309 patients tested positive for SARS-CoV-2. Age >65 years (P = 0.036), male sex (P = 0.003), high Charlson comorbidity index (P = 0.042), lung cancer (P = 0.018), immune checkpoint inhibitor (P = 0.036), and receipt of one or no dose of COVID-19 vaccine (P = 0.003) were significant predictors. The three machine learning algorithms revealed that the mean ± SD area-under-the-curve values predicting delayed viral clearance with the cut-off cycle threshold value ≥30 was 0.72 ± 0.11.

CONCLUSION

We identified subgroups with delayed viral clearance that may benefit from targeted interventions.

Coronavirus Disease-2019 in the Immunocompromised Host

Immunocompromised hosts, which encompass a diverse population of persons with malignancies, human immunodeficiency virus disease, solid organ, and hematologic transplants, autoimmune diseases, and primary immunodeficiencies, bear a significant burden of the morbidity and mortality due to coronavirus disease-2019 (COVID-19). Immunocompromised patients who develop COVID-19 have a more severe illness, higher hospitalization rates, and higher mortality rates than immunocompetent patients. There are no well-defined treatment strategies that are specific to immunocompromised patients and vaccines, monoclonal antibodies, and convalescent plasma are variably effective. This review focuses on the specific impact of COVID-19 in immunocompromised patients and the gaps in knowledge that require further study.

Safety and Immunogenicity of the Inactivated COVID-19 Vaccine Booster in People Living with HIV in China

Current knowledge regarding the long-term humoral response of people infected with human immunodeficiency virus to the third dose of inactivated coronavirus disease (COVID-19) vaccine is incomplete. As a result, concerns remain about the safety and efficacy of the vaccination. To improve our understanding of the safety and immunogenicity of the COVID-19 inactivated vaccine booster in people living with HIV (PLWH), a prospective study was conducted on participants who had not yet received a third dose of the COVID-19 inactivated vaccine, had no history of SARS-CoV-2 infection, and had received a second dose of the vaccine more than six months prior. The primary safety outcomes included the incidence of adverse reactions, changes in CD4⁺ T-cell count, viral load, blood routine examination, liver and kidney function examination, blood sugar, and blood lipid examination. The pseudovirus-neutralizing antibody responses to the D614G variant, Delta variant, and Omicron variants BA.5 and BF.7 were evaluated before vaccination, 14 days, 28 days, 3 months, and 6 months after vaccination to evaluate the immune response of PLWH to the injection of inactivated vaccine booster and the safety of the vaccine. In conclusion, COVID-19 vaccine booster shots were effective in PLWH, resulting in an increase in the number of CD4⁺ T-cells, neutralizing antibodies that lasted up to six months, and higher levels of neutralizing antibodies lasting approximately 3 months. However, the vaccine protection against the two variants of BA.5 and BF.7 was significantly lower than that of D614G and Delta.

High-throughput interrogation of immune responses using the Human Immune Profiling Pipeline

The current abundance of immunotherapy clinical trials presents an opportunity to learn about the underlying mechanisms and pharmacodynamic effects of novel drugs on the human immune system. Here, we present a protocol to study how these immune responses impact clinical outcomes using large-scale high-throughput immune profiling of clinical cohorts. We describe the Human Immune Profiling Pipeline, which comprises an end-to-end solution from flow cytometry results to computational approaches and unsupervised patient clustering based on lymphocyte landscape. For complete details on the use and execution of this protocol, please refer to Lyudovyk et al. (2022).1.

SARS-CoV-2-Specific T Cell Responses in Immunocompromised Individuals with Cancer, HIV or Solid Organ Transplants

Adaptive immune responses play an important role in the clinical course of SARS-CoV-2 infection. While evaluations of the virus-specific defense often focus on the humoral response, cellular immunity is crucial for the successful control of infection, with the early development of cytotoxic T cells being linked to efficient viral clearance. Vaccination against SARS-CoV-2 induces both CD4+ and CD8+ T cell responses and permits protection from severe COVID-19, including infection with the currently circulating variants of concern. Nevertheless, in immunocompromised individuals, first data imply significantly impaired SARS-CoV-2-specific immune responses after both natural infection and vaccination. Hence, these high-risk groups require particular consideration, not only in routine clinical practice, but also in the development of future vaccination strategies. In order to assist physicians in the guidance of immunocompromised patients, concerning the management of infection or the benefit of (booster) vaccinations, this review aims to provide a concise overview of the current knowledge about SARS-CoV-2-specific cellular immune responses in the vulnerable cohorts of cancer patients, people living with HIV (PLWH), and solid organ transplant recipients (SOT). Recent findings regarding the virus-specific cellular immunity in these differently immunocompromised populations might influence clinical decision-making in the future.

Factors affecting prolonged SARS-CoV-2 infection and development and validation of predictive nomograms

Prolonged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has received much attention since it is associated with mortality and is hypothesized as the cause of long COVID-19 and the emergence of a new variant of concerns. However, a prediction model for the accurate prediction of prolonged infection is still lacking. A total of 2938 confirmed patients with COVID-19 diagnosed by positive reverse transcriptase-polymerase chain reaction tests were recruited retrospectively. This study cohort was divided into a training set (70% of study patients; n = 2058) and a validation set (30% of study patients; n = 880). Univariate and multivariate logistic regression analyses were utilized to identify predictors for prolonged infection. Model 1 included only preadmission variables, whereas Model 2 also included after-admission variables. Nomograms based on variables of Model 1 and Model 2 were built for clinical use. The efficiency of nomograms was evaluated by using the area under the curve, calibration curves, and concordance indexes (C-index). Independent predictors of prolonged infection included in Model 1 were: age ≥75 years, chronic kidney disease, chronic lung disease, partially or fully vaccinated, and booster. Additional independent predictors in Model 2 were: treated with nirmatrelvir/ritonavir more than 5 days after diagnosis and glucocorticoid. The inclusion of after-admission variables in the model slightly improved the discriminatory power (C-index in the training cohort: 0.721 for Model 1 and 0.737 for Model 2; in the validation cohort: 0.699 for Model 1 and 0.719 for Model 2). In our study, we developed and validated predictive models based on readily available variables of preadmission and after-admission for predicting prolonged SARS-CoV-2 infection of patients with COVID-19.

Anti-spike T-cell and Antibody Responses to SARS-CoV-2 mRNA Vaccines in Patients with Hematologic Malignancies

The anti-spike T-cell and antibody responses to SARS-CoV-2 mRNA vaccines in patients with B-cell malignancies were examined in a real-world setting. A next-generation sequencing (NGS)-based molecular assay was used to assess SARS-CoV-2-specific T-cell responses. After the second dose, 58% (166/284) of seropositive and 45% (99/221) of seronegative patients display anti-spike T cells. The percentage of patients who displayed T-cell response was higher among patients receiving mRNA-1273 vaccines compared with those receiving BNT162b2 vaccines. After the third vaccination, 40% (137/342) of patients seroconverted, although only 22% displayed sufficient antibody levels associated with the production of neutralizing antibodies. 97% (717/738) of patients who were seropositive before the third dose had markedly elevated anti-spike antibody levels. Anti-spike antibody levels, but not T-cell responses, were depressed by B cell-directed therapies. Vaccinated patients with B-cell malignancies with a poor response to SARS-CoV-2 vaccines may remain vulnerable to COVID-19 infections.

SIGNIFICANCE

This study represents the first investigation of SARS-CoV-2-specific immune responses to vaccination in a patient registry using an NGS-based method for T-cell receptor repertoire-based analysis combined with anti-spike antibody assessments. Vaccinated patients with B cell-derived hematologic malignancies are likely at higher risk of infection or severe COVID-19. This article is highlighted in the In This Issue feature, p. 476.

SARS-CoV-2-specific T cells in the changing landscape of the COVID-19 pandemic

Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with increasing ability to evade neutralizing antibodies have emerged. Thus, earlier interest in defining the correlates of protection from infection, mainly mediated by humoral immunity, has shifted to correlates of protection from disease, which require a more comprehensive analysis of both humoral and cellular immunity. In this review, we summarized the evidence that supports the role of SARS-CoV-2-specific T cells induced by infection, by vaccination or by their combination (defined as hybrid immunity) in disease protection. We then analyzed the different epidemiological and virological variables that can modify the magnitude, function, and anatomical localization of SARS-CoV-2-specific T cells and their influence in the possible ability of T cells to protect the host from severe COVID-19 development.

SARS-CoV-2 in immunocompromised individuals

Immunocompromised individuals and particularly those with hematologic malignancies are at increased risk for SARS-CoV-2-associated morbidity and mortality due to immunologic deficits that limit prevention, treatment, and clearance of the virus. Understanding the natural history of viral infections in people with impaired immunity due to underlying conditions, immunosuppressive therapy, or a combination thereof has emerged as a critical area of investigation during the COVID-19 pandemic. Studies focused on these individuals have provided key insights into aspects of innate and adaptive immunity underlying both the antiviral immune response and excess inflammation in the setting of COVID-19. This review presents what is known about distinct states of immunologic vulnerability to SARS-CoV-2 and how this information can be harnessed to improve prevention and treatment strategies for immunologically high-risk populations.

Safety and immunogenicity of inactivated SARS-CoV-2 vaccines in people with gastrointestinal cancer

OBJECTIVES

This study aimed to evaluate the safety and immunogenicity of inactivated COVID-19 vaccines in patients with gastrointestinal cancer (GI) cancer. The role of memory B cells (MBCs) in the humoral response to COVID-19 vaccination was also investigated.

METHODS

In this prospective observational study, GI cancer patients and healthy individuals who had received 2 doses of inactivated COVID-19 vaccines were included. The data regarding adverse effects, serum anti-receptor binding domain (RBD)-IgG, neutralizing antibodies (NAbs), and frequencies of MBCs were collected prospectively.

RESULTS

The inactivated COVID-19 vaccines were safe and well tolerated. Serum anti-RBG-IgG and NAbs were lower for cancer patients. Old age, high ASA score, and receiving active chemotherapy were risk factors for lower antibody titers. The frequencies of activated and resting MBCs decreased in (17.45% vs 38.11%, P = 0.002; 16.98% vs 34.13%, P = 0.023), while the frequencies of intermediate and atypical MBCs increased in cancer patients (40.06% vs 19.87%, P = 0.010; 25.47% vs 16.61%, P = 0.025). The serum antibody titer decreased gradually during follow-up but increased when a booster vaccine was given.

CONCLUSION

The inactivated COVID-19 vaccines were well tolerated in patients with GI cancer but with lower immunogenicity. The subpopulations of MBCs were disordered in cancer patients, and a booster vaccine may be prioritized for them.

Heterogenous CD8+ T Cell Maturation and 'Polarization' in Acute and Convalescent COVID-19 Patients

BACKGROUND

The adaptive antiviral immune response requires interaction between CD8+ T cells, dendritic cells, and Th1 cells for controlling SARS-CoV-2 infection, but the data regarding the role of CD8+ T cells in the acute phase of COVID-19 and post-COVID-19 syndrome are still limited.

METHODS

. Peripheral blood samples collected from patients with acute COVID-19 (n = 71), convalescent subjects bearing serum SARS-CoV-2 N-protein-specific IgG antibodies (n = 51), and healthy volunteers with no detectable antibodies to any SARS-CoV-2 proteins (HC, n = 46) were analyzed using 10-color flow cytometry.

RESULTS

Patients with acute COVID-19 vs. HC and COVID-19 convalescents showed decreased absolute numbers of CD8+ T cells, whereas the frequency of CM and TEMRA CD8+ T cells in acute COVID-19 vs. HC was elevated. COVID-19 convalescents vs. HC had increased naïve and CM cells, whereas TEMRA cells were decreased compared to HC. Cell-surface CD57 was highly expressed by the majority of CD8+ T cells subsets during acute COVID-19, but convalescents had increased CD57 on 'naïve', CM, EM4, and pE1 2-3 months post-symptom onset. CXCR5 expression was altered in acute and convalescent COVID-19 subjects, whereas the frequencies of CXCR3+ and CCR4+ cells were decreased in both patient groups vs. HC. COVID-19 convalescents had increased CCR6-expressing CD8+ T cells. Moreover, CXCR3+CCR6- Tc1 cells were decreased in patients with acute COVID-19 and COVID-19 convalescents, whereas Tc2 and Tc17 levels were increased compared to HC. Finally, IL-27 negatively correlated with the CCR6+ cells in acute COVID-19 patients.

CONCLUSIONS

We described an abnormal CD8+ T cell profile in COVID-19 convalescents, which resulted in lower frequencies of effector subsets (TEMRA and Tc1), higher senescent state (upregulated CD57 on 'naïve' and memory cells), and higher frequencies of CD8+ T cell subsets expressing lung tissue and mucosal tissue homing molecules (Tc2, Tc17, and Tc17.1). Thus, our data indicate that COVID-19 can impact the long-term CD8+ T cell immune response.