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1.
International Conference on Enterprise Information Systems, ICEIS - Proceedings ; 1:263-270, 2023.
Article in English | Scopus | ID: covidwho-20239723

ABSTRACT

This research aims to analyze the resilience of humanitarian supply chains, with a focus on the role of information systems, through a case study of Médecins Sans Frontières Logistique during the COVID-19 pandemic. The empirical research methodology is based on a qualitative study, which includes semi-structured interviews with key actors and operators from the Médecins Sans Frontières Logistique during the COVID-19 crisis in 2020 and 2021. The paper highlights the crucial and inherent role of information systems on each of the four dimensions of humanitarian supply chain resilience: reorganization capacity, collaboration, flexibility, and humanitarian culture. Drawing on recent theoretical works on supply chain resilience as well as empirical results, the paper underscores the importance of information systems and proposes a conceptual model of the relationship between humanitarian supply chain resilience and the role of information systems. The value of this research is linked to its empirical and qualitative study of a Non-Governmental Organization logistics operation during an international crisis, which contributes not only to the literature on resilience, but also provides guidance for managers to target their actions responsively and proactively to enhance resilience over time.. Copyright © 2023 by SCITEPRESS - Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

3.
Supply Chain Management ; 2023.
Article in English | Scopus | ID: covidwho-2300054

ABSTRACT

Purpose: This paper aims to study the dimensions and subdimensions of humanitarian supply chain resilience through the case of an non-governmental organization (NGO) logistics organization facing the international COVID-19 pandemic. Design/methodology/approach: The methodology of this empirical research paper is based on a qualitative study using semistructured interviews with key actors of the Médecins Sans Frontières Logistique (MSF Log), NGO during the COVID-19 crisis in 2020 and 2021. Findings: The data analysis highlighted four main dimensions of humanitarian supply chain resilience: organizational capacity, collaboration, flexibility and humanitarian culture. The transversal importance of the information system and that of the humanitarian culture were also pointed out. Furthermore, the authors have identified the subdimensions of each dimension;these subdimensions further elaborate the main dimension and provide a more detailed understanding of the concept. These dimensions require both proactive and reactive actions to be effective. Finally, based on these empirical results, a conceptual model of humanitarian supply chain resilience is proposed. Research limitations/implications: Additionally, further research can be done to explore the impact of digital technologies on the humanitarian supply chain resilience and how these technologies can be used to improve the resilience of humanitarian supply chains. Additionally, future research can also be conducted to explore how to measure the resilience of humanitarian supply chains and how to develop methods to improve the resilience of these supply chains. Practical implications: The dimensions and subdimensions of resilience that have been highlighted may provide a guide for managers to target their actions, both responsively and proactively, to act on resilience over time when facing a crisis such as an international pandemic. Originality/value: The value of this research is linked to the findings that result not only from literature about resilience but are also founded on an empirical and qualitative study of an NGO logistics organization facing an international crisis. The research provides an in-depth understanding of the practical application of supply chain resilience in a humanitarian context and the specific challenges and opportunities that arose during the COVID-19 pandemic for MSF Log. It also highlights the importance of information systems and humanitarian culture in maintaining the supply chain resilience. The findings of this research can be used as a guide for other humanitarian organizations to improve their supply chain resilience in times of crisis. © 2023, Emerald Publishing Limited.

5.
Int J Infect Dis ; 129: 207-215, 2023 Apr.
Article in English | MEDLINE | ID: covidwho-2229333

ABSTRACT

OBJECTIVES: The X-chromosome contains the largest number of immune-related genes, which play a major role in COVID-19 symptomatology and susceptibility. Here, we had a unique opportunity to investigate, for the first time, COVID-19 outcomes in six unvaccinated young Brazilian patients with Turner syndrome (TS; 45, X0), including one case of critical illness in a child aged 10 years, to evaluate their immune response according to their genetic profile. METHODS: A serological analysis of humoral immune response against SARS-CoV-2, phenotypic characterization of antiviral responses in peripheral blood mononuclear cells after stimuli, and the production of cytotoxic cytokines of T lymphocytes and natural killer cells were performed in blood samples collected from the patients with TS during the convalescence period. Whole exome sequencing was also performed. RESULTS: Our volunteers with TS showed a delayed or insufficient humoral immune response to SARS-CoV-2 (particularly immunoglobulin G) and a decrease in interferon-γ production by cluster of differentiation (CD)4+ and CD8+ T lymphocytes after stimulation with toll-like receptors 7/8 agonists. In contrast, we observed a higher cytotoxic activity in the volunteers with TS than the volunteers without TS after phorbol myristate acetate/ionomycin stimulation, particularly granzyme B and perforin by CD8+ and natural killer cells. Interestingly, two volunteers with TS carry rare genetic variants in genes that regulate type I and III interferon immunity. CONCLUSION: Following previous reports in the literature for other conditions, our data showed that patients with TS may have an impaired immune response against SARS-CoV-2. Furthermore, other medical conditions associated with TS could make them more vulnerable to COVID-19.


Subject(s)
COVID-19 , Turner Syndrome , Child , Humans , SARS-CoV-2 , Turner Syndrome/complications , Turner Syndrome/genetics , Leukocytes, Mononuclear , CD8-Positive T-Lymphocytes , Antibodies, Viral
6.
J Vasc Surg ; 77(4): 1165-1173.e1, 2023 04.
Article in English | MEDLINE | ID: covidwho-2237126

ABSTRACT

OBJECTIVE: Hypercoagulability is common in severe acute respiratory syndrome coronavirus 2 and has been associated with arterial thrombosis leading to acute limb ischemia (ALI). Our objective was to determine the outcomes of concurrent coronavirus disease 2019 (COVID-19) infection and ALI, particularly during the Delta variant surge and the impact of vaccination status. METHODS: A retrospective review was performed of patients treated at a single health care system between March 2020 and December 2021 for ALI and recent (<14 days) COVID-19 infection or who developed ALI during hospitalization for the same disease. Patients were grouped by year as well as by pre and post Delta variant emergence in 2021 based on the World Health Organization timeline (January to May vs June to December). Baseline demographics, imaging, interventions, and outcomes were evaluated. A control cohort of all patients with ALI requiring surgical intervention for a 2-year period prior to the pandemic was used for comparison. Primary outcomes were in-hospital mortality and amputation-free survival. Kaplan-Meier survival and Cox proportional hazards analysis were performed. RESULTS: Forty acutely ischemic limbs were identified in 36 patients with COVID-19, the majority during the Delta surge (52.8%) and after the wide availability of vaccines. The rate of COVID-19-associated ALI, although low overall, nearly doubled during the Delta surge (0.37% vs 0.20%; P = .09). Intervention (open or endovascular revascularization vs primary amputation) was performed on 31 limbs in 28 individuals, with the remaining eight treated with systemic anti-coagulation. Postoperative mortality was 48%, and overall mortality was 50%. Major amputation following revascularization was significantly higher with COVID-19 ALI (25% vs 3%; P = .006) compared with the pre-pandemic group. Thirty-day amputation-free survival was significantly lower (log-rank P < .001). COVID-19 infection (adjusted hazard ratio, 6.2; P < .001) and age (hazard ratio, 1.1; P = .006) were associated with 30-day amputation in multivariate analysis. Severity of COVID-19 infection, defined as vasopressor usage, was not associated with post-revascularization amputation. There was a higher incidence of re-thrombosis in the latter half of 2021 with the Delta surge, as reintervention for recurrent ischemia of the same limb was more common than our previous experience (21% vs 0%; P = .55). COVID-19-associated limb ischemia occurred almost exclusively in non-vaccinated patients (92%). CONCLUSIONS: ALI observed with Delta appears more resistant to standard therapy. Unvaccinated status correlated highly with ALI occurrence in the setting of COVID-19 infection. Information of limb loss as a COVID-19 complication among non-vaccinated patients may help to increase compliance.


Subject(s)
COVID-19 Vaccines , COVID-19 , Endovascular Procedures , Peripheral Arterial Disease , Humans , COVID-19/complications , Endovascular Procedures/adverse effects , Ischemia/diagnostic imaging , Ischemia/etiology , Ischemia/therapy , Limb Salvage , Lower Extremity/blood supply , Retrospective Studies , Risk Factors , SARS-CoV-2 , Treatment Outcome , Vaccines , COVID-19 Vaccines/adverse effects
8.
Immun Ageing ; 19(1): 57, 2022 Nov 16.
Article in English | MEDLINE | ID: covidwho-2116656

ABSTRACT

BACKGROUND: Although older adults are at a high risk of severe or critical Covid-19, there are many cases of unvaccinated centenarians who had a silent infection or recovered from mild or moderate Covid-19. We studied three Brazilian supercentenarians, older than 110 years, who survived Covid-19 in 2020 before being vaccinated. RESULTS: Despite their advanced age, humoral immune response analysis showed that these individuals displayed robust levels of IgG and neutralizing antibodies (NAbs) against SARS-CoV-2. Enrichment of plasma proteins and metabolites related to innate immune response and host defense was also observed. None presented autoantibodies (auto-Abs) to type I interferon (IFN). Furthermore, these supercentenarians do not carry rare variants in genes underlying the known inborn errors of immunity, including particular inborn errors of type I IFN. CONCLUSION: These observations suggest that their Covid-19 resilience might be a combination of their genetic background and their innate and adaptive immunity.

9.
Front Immunol ; 13: 975918, 2022.
Article in English | MEDLINE | ID: covidwho-2114093

ABSTRACT

Background: Although aging correlates with a worse prognosis for Covid-19, super elderly still unvaccinated individuals presenting mild or no symptoms have been reported worldwide. Most of the reported genetic variants responsible for increased disease susceptibility are associated with immune response, involving type I IFN immunity and modulation; HLA cluster genes; inflammasome activation; genes of interleukins; and chemokines receptors. On the other hand, little is known about the resistance mechanisms against SARS-CoV-2 infection. Here, we addressed polymorphisms in the MHC region associated with Covid-19 outcome in super elderly resilient patients as compared to younger patients with a severe outcome. Methods: SARS-CoV-2 infection was confirmed by RT-PCR test. Aiming to identify candidate genes associated with host resistance, we investigated 87 individuals older than 90 years who recovered from Covid-19 with mild symptoms or who remained asymptomatic following positive test for SARS-CoV-2 as compared to 55 individuals younger than 60 years who had a severe disease or died due to Covid-19, as well as to the general elderly population from the same city. Whole-exome sequencing and an in-depth analysis of the MHC region was performed. All samples were collected in early 2020 and before the local vaccination programs started. Results: We found that the resilient super elderly group displayed a higher frequency of some missense variants in the MUC22 gene (a member of the mucins' family) as one of the strongest signals in the MHC region as compared to the severe Covid-19 group and the general elderly control population. For example, the missense variant rs62399430 at MUC22 is two times more frequent among the resilient super elderly (p = 0.00002, OR = 2.24). Conclusion: Since the pro-inflammatory basal state in the elderly may enhance the susceptibility to severe Covid-19, we hypothesized that MUC22 might play an important protective role against severe Covid-19, by reducing overactive immune responses in the senior population.


Subject(s)
COVID-19 , Aged , Humans , Brazil/epidemiology , COVID-19/epidemiology , COVID-19/genetics , Genes, MHC Class II , HLA-A Antigens , SARS-CoV-2/genetics
10.
Frontiers in medicine ; 9, 2022.
Article in English | EuropePMC | ID: covidwho-2072962

ABSTRACT

Background The influence of the host genome on coronavirus disease 2019 (COVID-19) susceptibility and severity is supported by reports on monozygotic (MZ) twins where both were infected simultaneously with similar disease outcomes, including several who died due to the SARS-CoV-2 infection within days apart. However, successive exposures to pathogens throughout life along with other environmental factors make the immune response unique for each individual, even among MZ twins. Case presentation and methods Here we report a case of a young adult monozygotic twin pair, who caught attention since both presented simultaneously severe COVID-19 with the need for oxygen support despite age and good health conditions. One of the twins, who spent more time hospitalized, reported symptoms of long-COVID even 7 months after infection. Immune cell profile and specific responses to SARS-CoV-2 were evaluated as well as whole exome sequencing. Conclusion Although the MZ twin brothers shared the same genetic mutations which may be associated with their increased risk of developing severe COVID-19, their clinical progression was different, reinforcing the role of both immune response and genetics in the COVID-19 presentation and course. Besides, post-COVID syndrome was observed in one of them, corroborating an association between the duration of hospitalization and the occurrence of long-COVID symptoms.

12.
JAMA Oncol ; 8(10): 1477-1483, 2022 10 01.
Article in English | MEDLINE | ID: covidwho-1990392

ABSTRACT

Importance: It has become common practice to offer immunocompromised patients with hematologic cancers a third COVID-19 vaccination dose, but data substantiating this are scarce. Objective: To assess whether a third mRNA-1273 vaccination is associated with increased neutralizing antibody concentrations in immunocompromised patients with hematologic cancers comparable to levels obtained in healthy individuals after the standard 2-dose mRNA-1273 vaccination schedule. Design, Setting, and Participants: This prospective observational cohort study was conducted at 4 university hospitals in the Netherlands and included 584 evaluable patients spanning the spectrum of hematologic cancers and 44 randomly selected age-matched adults without malignant or immunodeficient comorbidities. Exposures: One additional mRNA-1273 vaccination 5 months after completion of the standard 2-dose mRNA-1273 vaccination schedule. Main Outcomes and Measures: Serum immunoglobulin G (IgG) antibodies to spike subunit 1 (S1) antigens prior to and 4 weeks after a third mRNA-1273 vaccination, and antibody neutralization capacity of wild-type, Delta, and Omicron variants in a subgroup of patients. Results: In this cohort of 584 immunocompromised patients with hematologic cancers (mean [SD] age, 60 [11.2] years; 216 [37.0%] women), a third mRNA-1273 vaccination was associated with median S1-IgG concentrations comparable to concentrations obtained by healthy individuals after the 2-dose mRNA-1273 schedule. The rise in S1-IgG concentration after the third vaccination was most pronounced in patients with a recovering immune system, but potent responses were also observed in patients with persistent immunodeficiencies. Specifically, patients with myeloid cancers or multiple myeloma and recipients of autologous or allogeneic hematopoietic cell transplantation (HCT) reached median S1-IgG concentrations similar to those obtained by healthy individuals after a 2-dose schedule. Patients receiving or shortly after completing anti-CD20 therapy, CD19-directed chimeric antigen receptor T-cell therapy recipients, and patients with chronic lymphocytic leukemia receiving ibrutinib were less responsive or unresponsive to the third vaccination. In the 27 patients who received cell therapy between the second and third vaccination, S1 antibodies were preserved, but a third mRNA-1273 vaccination was not associated with significantly enhanced S1-IgG concentrations except for patients with multiple myeloma receiving autologous HCT. A third vaccination was associated with significantly improved neutralization capacity per antibody. Conclusions and Relevance: Results of this cohort study support that the primary schedule for immunocompromised patients with hematologic cancers should be supplemented with a delayed third vaccination. Patients with B-cell lymphoma and allogeneic HCT recipients need to be revaccinated after treatment or transplantation. Trial Registration: EudraCT Identifier: 2021-001072-41.


Subject(s)
COVID-19 , Hematologic Neoplasms , Multiple Myeloma , Receptors, Chimeric Antigen , Humans , Adult , Female , Middle Aged , Male , Antibody Formation , 2019-nCoV Vaccine mRNA-1273 , COVID-19/prevention & control , Prospective Studies , Cohort Studies , COVID-19 Vaccines , SARS-CoV-2 , Hematologic Neoplasms/therapy , Immunocompromised Host , Antibodies, Neutralizing , Immunoglobulin G
13.
Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research ; 25(7):S515-S516, 2022.
Article in English | EuropePMC | ID: covidwho-1905226
14.
medrxiv; 2022.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2022.04.08.22273602

ABSTRACT

ImportanceIn patients with hematologic malignancies, the immunogenicity of the standard 2-dose mRNA-1273 coronavirus disease 19 (COVID-19) vaccination schedule is often insufficient due to underlying disease and current or recent therapy. ObjectiveTo determine whether a 3rd mRNA-1273 vaccination raises antibody concentrations in immunocompromised hematology patients to levels obtained in healthy individuals after the standard 2-dose mRNA-1273 vaccination schedule. DesignProspective observational cohort study. SettingFour academic hospitals in the Netherlands. Participants584 evaluable immunocompromised hematology patients, all grouped in predefined cohorts spanning the spectrum of hematologic malignancies. ExposureOne additional vaccination with mRNA-1273 5 months after completion of the standard 2-dose mRNA-1273 vaccination schedule. Main Outcomes and MeasuresSerum IgG antibodies to spike subunit 1 (S1) antigens prior to and 4 weeks after each vaccination, and pseudovirus neutralization of wildtype, delta and omicron variants in a subgroup of patients. ResultsIn immunocompromised hematology patients, a 3rd mRNA-1273 vaccination led to median S1 IgG concentrations comparable to concentrations obtained by healthy individuals after the 2-dose mRNA-1273 schedule. The rise in S1 IgG concentration after the 3rd vaccination was most pronounced in patients with a recovering immune system, but potent responses were also observed in patients with persistent immunodeficiencies. Specifically, patients with myeloid malignancies or multiple myeloma, and recipients of autologous or allogeneic hematopoietic cell transplantation (HCT) reached median S1 IgG concentrations similar to those obtained by healthy individuals after a 2-dose schedule. Patients on or shortly after rituximab therapy, CD19-directed chimeric antigen receptor T cell therapy recipients, and chronic lymphocytic leukemia patients on ibrutinib were less or unresponsive to the 3rd vaccination. In the 27 patients who received cell therapy between the 2nd and 3rd vaccination, S1 antibodies were preserved, but a 3rd mRNA-1273 vaccination did not significantly enhance S1 IgG concentrations except for multiple myeloma patients receiving autologous HCT. A 3rd vaccination significantly improved neutralization capacity per antibody. Conclusions and RelevanceThe primary schedule for immunocompromised patients with hematologic malignancies should be supplemented with a delayed 3rd vaccination. B cell lymphoma patients and allogeneic HCT recipients need to be revaccinated after treatment or transplantation. Trial RegistrationEudraCT 2021-001072-41 Key pointsO_ST_ABSQuestionC_ST_ABSCan a 3rd mRNA-1273 vaccination improve COVID-19 antibody concentrations in immunocompromised hematology patients to levels similar to healthy adults after the standard 2-dose mRNA-1273 schedule? FindingsIn this prospective observational cohort study that included 584 immunocompromised hematology patients, a 3rd mRNA-1273 vaccination significantly improved SARS-CoV-2 antibody concentrations to levels not significantly different from those obtained by healthy individuals after the standard 2-dose mRNA-1273 vaccination schedule. Pseudovirus neutralization capacity per antibody of wild type virus and variants of concern also significantly improved. MeaningThe primary COVID-19 vaccination schedule for immunocompromised patients with hematologic malignancies should be supplemented with a delayed 3rd vaccination.


Subject(s)
Coronavirus Infections , Lymphoma, B-Cell , Immunologic Deficiency Syndromes , Leukemia, Lymphocytic, Chronic, B-Cell , Hematologic Neoplasms , COVID-19 , Multiple Myeloma
15.
Discov Ment Health ; 2(1): 1, 2022.
Article in English | MEDLINE | ID: covidwho-1694058

ABSTRACT

BACKGROUND: COVID-19 has affected millions of people worldwide. Clinical manifestations range from severe cases with lethal outcome to mild or asymptomatic cases. Although the proportion of infected individuals does not differ between sexes, men are more susceptible to severe COVID-19, with a higher risk of death than women. Also, men are pointed out as more lax regarding protective measures, mask wearing and vaccination. Thus, we questioned whether sex-bias may be explained by biological pathways and/or behavioral aspects or both. METHODS: Between July 2020 and July 2021, we performed an epidemiological survey including 1744 unvaccinated adult Brazilian couples, with there was at least one infected symptomatic member, who were living together during the COVID-19 infection without protective measures. Presence or absence of infection was confirmed by RT-PCR and/or serology results. Couples were divided into two groups: (1) both partners were infected (concordant couples) and (2) one partner was infected and the spouse remained asymptomatic despite the close contact with the COVID-19 symptomatic partner (discordant couples). Statistical analysis of the collected data was performed aiming to verify a differential transmission potential between genders in couples keeping contact without protective measures. RESULTS: The combination of our collected data showed that the man is the first (or the only) affected member in most cases when compared to women and that this difference may be explained by biological and behavioral factors. CONCLUSIONS: The present study confirmed the existence of gender differences not only for susceptibility to infection and resistance to COVID-19 but also in its transmission rate.

16.
Mol Psychiatry ; 27(4): 1936-1944, 2022 04.
Article in English | MEDLINE | ID: covidwho-1683976

ABSTRACT

The world population is getting older and studies aiming to enhance our comprehension of the underlying mechanisms responsible for health span are of utmost interest for longevity and as a measure for health care. In this review, we summarized previous genetic association studies (GWAS) and next-generation sequencing (NGS) of elderly cohorts. We also present the updated hypothesis for the aging process, together with the factors associated with healthy aging. We discuss the relevance of studying older individuals and build databanks to characterize the presence and resistance against late-onset disorders. The identification of about 2 million novel variants in our cohort of more than 1000 elderly Brazilians illustrates the importance of studying highly admixed populations of non-European ancestry. Finally, the ascertainment of nonagenarians and particularly of centenarians who were recovered from COVID-19 or remained asymptomatic opens new avenues of research aiming to enhance our comprehension of biological mechanisms associated with resistance against pathogens.


Subject(s)
COVID-19 , Longevity , Aged , Aged, 80 and over , Brazil , Cohort Studies , Genetic Association Studies , Humans , Longevity/genetics
17.
Blood Adv ; 6(5): 1537-1546, 2022 03 08.
Article in English | MEDLINE | ID: covidwho-1666615

ABSTRACT

Vaccination guidelines for patients treated for hematological diseases are typically conservative. Given their high risk for severe COVID-19, it is important to identify those patients that benefit from vaccination. We prospectively quantified serum immunoglobulin G (IgG) antibodies to spike subunit 1 (S1) antigens during and after 2-dose mRNA-1273 (Spikevax/Moderna) vaccination in hematology patients. Obtaining S1 IgG ≥ 300 binding antibody units (BAUs)/mL was considered adequate as it represents the lower level of S1 IgG concentration obtained in healthy individuals, and it correlates with potent virus neutralization. Selected patients (n = 723) were severely immunocompromised owing to their disease or treatment thereof. Nevertheless, >50% of patients obtained S1 IgG ≥ 300 BAUs/mL after 2-dose mRNA-1273. All patients with sickle cell disease or chronic myeloid leukemia obtained adequate antibody concentrations. Around 70% of patients with chronic graft-versus-host disease (cGVHD), multiple myeloma, or untreated chronic lymphocytic leukemia (CLL) obtained S1 IgG ≥ 300 BAUs/mL. Ruxolitinib or hypomethylating therapy but not high-dose chemotherapy blunted responses in myeloid malignancies. Responses in patients with lymphoma, patients with CLL on ibrutinib, and chimeric antigen receptor T-cell recipients were low. The minimal time interval after autologous hematopoietic cell transplantation (HCT) to reach adequate concentrations was <2 months for multiple myeloma, 8 months for lymphoma, and 4 to 6 months after allogeneic HCT. Serum IgG4, absolute B- and natural killer-cell number, and number of immunosuppressants predicted S1 IgG ≥ 300 BAUs/mL. Hematology patients on chemotherapy, shortly after HCT, or with cGVHD should not be precluded from vaccination. This trial was registered at Netherlands Trial Register as #NL9553.


Subject(s)
COVID-19 , Hematology , 2019-nCoV Vaccine mRNA-1273 , COVID-19/prevention & control , COVID-19 Vaccines , Humans , SARS-CoV-2 , Vaccination
18.
Open Biol ; 12(2): 210240, 2022 02.
Article in English | MEDLINE | ID: covidwho-1662161

ABSTRACT

Recurrence of COVID-19 in recovered patients has been increasingly reported. However, the immune mechanisms behind the recurrence have not been thoroughly investigated. The presence of neutralizing antibodies (nAbs) in recurrence/reinfection cases suggests that other types of immune response are involved in protection against recurrence. Here, we investigated the innate type I/III interferon (IFN) response, binding and nAb assays and T-cell responses to severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) with IFN gamma (IFNγ) enzyme-linked spot assay (ELISPOT) in three pairs of young adult monozygotic (MZ) twins with previous confirmed COVID-19, one of them presenting a severe recurrence four months after the initial infection. Twin studies have been of paramount importance to comprehend the immunogenetics of infectious diseases. Each MZ twin pair was previously exposed to SARS-CoV-2, as seen by clinical reports. The six individuals presented similar overall recovered immune responses except for the recurrence case, who presented a drastically reduced number of recognized SARS-CoV-2 T-cell epitopes on ELISPOT as compared to her twin sister and the other twin pairs. Our results suggest that the lack of a broad T-cell response to initial infection may have led to recurrence, emphasizing that an effective SARS-CoV-2-specific T-cell immune response is key for complete viral control and avoidance of clinical recurrence of COVID-19.


Subject(s)
COVID-19/immunology , Epitopes, T-Lymphocyte/immunology , Immunity, Cellular , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Twins, Monozygotic , Adolescent , Adult , Female , Humans , Male , Recurrence
19.
Front Immunol ; 12: 742881, 2021.
Article in English | MEDLINE | ID: covidwho-1470759

ABSTRACT

Despite the high number of individuals infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who develop coronavirus disease 2019 (COVID-19) symptoms worldwide, many exposed individuals remain asymptomatic and/or uninfected and seronegative. This could be explained by a combination of environmental (exposure), immunological (previous infection), epigenetic, and genetic factors. Aiming to identify genetic factors involved in immune response in symptomatic COVID-19 as compared to asymptomatic exposed individuals, we analyzed 83 Brazilian couples where one individual was infected and symptomatic while the partner remained asymptomatic and serum-negative for at least 6 months despite sharing the same bedroom during the infection. We refer to these as "discordant couples". We performed whole-exome sequencing followed by a state-of-the-art method to call genotypes and haplotypes across the highly polymorphic major histocompatibility complex (MHC) region. The discordant partners had comparable ages and genetic ancestry, but women were overrepresented (65%) in the asymptomatic group. In the antigen-presentation pathway, we observed an association between HLA-DRB1 alleles encoding Lys at residue 71 (mostly DRB1*03:01 and DRB1*04:01) and DOB*01:02 with symptomatic infections and HLA-A alleles encoding 144Q/151R with asymptomatic seronegative women. Among the genes related to immune modulation, we detected variants in MICA and MICB associated with symptomatic infections. These variants are related to higher expression of soluble MICA and low expression of MICB. Thus, quantitative differences in these molecules that modulate natural killer (NK) activity could contribute to susceptibility to COVID-19 by downregulating NK cell cytotoxic activity in infected individuals but not in the asymptomatic partners.


Subject(s)
Asymptomatic Infections , COVID-19 , Histocompatibility Antigens , Major Histocompatibility Complex , SARS-CoV-2 , Adult , Aged , Brazil , COVID-19/genetics , COVID-19/immunology , Female , Genetic Predisposition to Disease , Genotype , Histocompatibility Antigens/genetics , Histocompatibility Antigens/immunology , Humans , Major Histocompatibility Complex/genetics , Major Histocompatibility Complex/immunology , Male , Middle Aged , Exome Sequencing
20.
medrxiv; 2021.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2021.09.29.21263145

ABSTRACT

Investigations on the concordance in monozygotic (MZ) as compared to dizygotic (DZ) twins may reveal if there is a genetic component increasing the susceptibility or resistance against an infectious disease. Here, we compared the concordance rates of SARS-CoV-2 infection in MZ versus DZ young twins who shared the same bedrooms and were equally exposed to the virus. The concordance rate was higher in the MZ group supporting a complex multifactorial inheritance responsible for SARS-Cov-2 infection.


Subject(s)
COVID-19 , Communicable Diseases
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