Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 23
Filter
1.
Nat Med ; 29(5): 1146-1154, 2023 05.
Article in English | MEDLINE | ID: covidwho-2320083

ABSTRACT

Obesity is associated with an increased risk of severe Coronavirus Disease 2019 (COVID-19) infection and mortality. COVID-19 vaccines reduce the risk of serious COVID-19 outcomes; however, their effectiveness in people with obesity is incompletely understood. We studied the relationship among body mass index (BMI), hospitalization and mortality due to COVID-19 among 3.6 million people in Scotland using the Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 (EAVE II) surveillance platform. We found that vaccinated individuals with severe obesity (BMI > 40 kg/m2) were 76% more likely to experience hospitalization or death from COVID-19 (adjusted rate ratio of 1.76 (95% confidence interval (CI), 1.60-1.94). We also conducted a prospective longitudinal study of a cohort of 28 individuals with severe obesity compared to 41 control individuals with normal BMI (BMI 18.5-24.9 kg/m2). We found that 55% of individuals with severe obesity had unquantifiable titers of neutralizing antibody against authentic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus compared to 12% of individuals with normal BMI (P = 0.0003) 6 months after their second vaccine dose. Furthermore, we observed that, for individuals with severe obesity, at any given anti-spike and anti-receptor-binding domain (RBD) antibody level, neutralizing capacity was lower than that of individuals with a normal BMI. Neutralizing capacity was restored by a third dose of vaccine but again declined more rapidly in people with severe obesity. We demonstrate that waning of COVID-19 vaccine-induced humoral immunity is accelerated in individuals with severe obesity. As obesity is associated with increased hospitalization and mortality from breakthrough infections, our findings have implications for vaccine prioritization policies.


Subject(s)
COVID-19 , Obesity, Morbid , Humans , COVID-19 Vaccines , Longitudinal Studies , Prospective Studies , COVID-19/epidemiology , COVID-19/prevention & control , SARS-CoV-2 , Obesity/epidemiology , Antibodies, Neutralizing , Antibodies, Viral , Vaccination
2.
Gac. méd. Méx ; 159(2): 157-163, mar.-abr. 2023. graf
Article in Spanish | WHO COVID, LILACS (Americas) | ID: covidwho-2307997

ABSTRACT

Resumen Los autoanticuerpos anticitocinas (ACAA) han sido reportados como causa importante de inmunodeficiencias secundarias. Altos títulos de autoanticuerpos neutralizantes pueden causar susceptibilidad a diferentes enfermedades infecciosas potencialmente mortales. Por ejemplo, se ha informado que autoanticuerpos neutralizantes contra IFNγ se correlacionan con susceptibilidad a infecciones micobacterianas y patógenos fúngicos intracelulares. Autoanticuerpos contra IL-6 se detectaron en pacientes con abscesos subcutáneos y celulitis estafilocócica recurrente; asimismo, pacientes con criptococosis, nocardiosis y proteinosis alveolar pulmonar fueron positivos a autoanticuerpos contra GM-CSF. También se ha establecido una relación entre los autoanticuerpos contra IL-17 e IL-22 y las infecciones crónicas por Candida en mucosas, que se han identificado en pacientes con poliendocrinopatía autoinmune tipo 1 o timoma. Recientemente se han reportado autoanticuerpos contra interferón tipo I durante el inicio de COVID-19 aguda. Estos ACAA se asemejan a defectos genéticos en citocinas o en sus rutas de señalización. Por ello, pueden considerarse fenocopias de inmunodeficiencias primarias. De esta forma, la detección de ACAA podría ser importante en el diagnóstico, particularmente en pacientes con enfermedades de aparición tardía, para decidir los tratamientos apropiados. Esta revisión presenta una descripción general de la comprensión actual de las inmunodeficiencias secundarias asociadas a ACAA.


Abstract Anti-cytokine autoantibodies (ACAA) have been reported to be an important cause of secondary immunodeficiencies. High titers of neutralizing autoantibodies may cause susceptibility to different life-threatening infectious diseases. For example, neutralizing autoantibodies against IFNγ have been reported to be correlated with susceptibility to mycobacterial infections and intracellular fungal pathogens. Autoantibodies against IL-6 were detected in patients with subcutaneous abscesses and recurrent staphylococcal cellulitis; on the other hand, patients with cryptococcosis, nocardiosis, and pulmonary alveolar proteinosis were positive for autoantibodies to GM-CSF. A relationship has also been established between autoantibodies against IL-17 and IL-22 and chronic mucosal Candida infections, which have been identified in patients with APECED or thymoma. Autoantibodies against type-I IFN have been recently reported during the onset of acute COVID-19. These ACAAs resemble genetic defects in cytokines or their signaling pathways. Therefore, they may be considered to be primary immunodeficiencies phenocopies. Consequently, the detection of ACAA could be important in the diagnosis of patients, particularly in the case of late-onset diseases, in order to decide appropriate treatments. This review presents an overview of current understanding of ACAA-associated secondary immunodeficiencies.

3.
Gac Med Mex ; 159(2): 154-160, 2023.
Article in English | MEDLINE | ID: covidwho-2293660

ABSTRACT

Anti-cytokine autoantibodies (ACAA) have been reported to be an important cause of secondary immunodeficiencies. High titers of neutralizing autoantibodies may cause susceptibility to different life-threatening infectious diseases. For example, neutralizing autoantibodies against IFNg have been reported to be correlated with susceptibility to mycobacterial infections and intracellular fungal pathogens. Autoantibodies against IL-6 were detected in patients with subcutaneous abscesses and recurrent staphylococcal cellulitis; on the other hand, patients with cryptococcosis, nocardiosis, and pulmonary alveolar proteinosis were positive for autoantibodies to GM-CSF. A relationship has also been established between autoantibodies against IL-17 and IL-22 and chronic mucosal Candida infections, which have been identified in patients with APECED or thymoma. Autoantibodies against type-I IFN have been recently reported during the onset of acute COVID-19. These ACAAs resemble genetic defects in cytokines or their signaling pathways. Therefore, they may be considered to be primary immunodeficiencies phenocopies. Consequently, the detection of ACAA could be important in the diagnosis of patients, particularly in the case of late-onset diseases, in order to decide appropriate treatments. This review presents an overview of current understanding of ACAA-associated secondary immunodeficiencies.


Los autoanticuerpos anticitocinas (ACAA) han sido reportados como causa importante de inmunodeficiencias secundarias. Altos títulos de autoanticuerpos neutralizantes pueden causar susceptibilidad a diferentes enfermedades infecciosas potencialmente mortales. Por ejemplo, se ha informado que autoanticuerpos neutralizantes contra IFNg se correlacionan con susceptibilidad a infecciones micobacterianas y patógenos fúngicos intracelulares. Autoanticuerpos contra IL-6 se detectaron en pacientes con abscesos subcutáneos y celulitis estafilocócica recurrente; asimismo, pacientes con criptococosis, nocardiosis y proteinosis alveolar pulmonar fueron positivos a autoanticuerpos contra GM-CSF. También se ha establecido una relación entre los autoanticuerpos contra IL-17 e IL-22 y las infecciones crónicas por Candida en mucosas, que se han identificado en pacientes con poliendocrinopatía autoinmune tipo 1 o timoma. Recientemente se han reportado autoanticuerpos contra interferón tipo I durante el inicio de COVID-19 aguda. Estos ACAA se asemejan a defectos genéticos en citocinas o en sus rutas de señalización. Por ello, pueden considerarse fenocopias de inmunodeficiencias primarias. De esta forma, la detección de ACAA podría ser importante en el diagnóstico, particularmente en pacientes con enfermedades de aparición tardía, para decidir los tratamientos apropiados. Esta revisión presenta una descripción general de la comprensión actual de las inmunodeficiencias secundarias asociadas a ACAA.


Subject(s)
COVID-19 , Cryptococcosis , Immunologic Deficiency Syndromes , Humans , Cytokines , Autoantibodies
4.
Intensive Care Med Exp ; 11(1): 9, 2023 Feb 24.
Article in English | MEDLINE | ID: covidwho-2273755

ABSTRACT

BACKGROUND: Divergence between deterioration to life-threatening COVID-19 or clinical improvement occurs for most within the first 14 days of symptoms. Life-threatening COVID-19 shares clinical similarities with Macrophage Activation Syndrome, which can be driven by elevated Free Interleukin-18 (IL-18) due to failure of negative-feedback release of IL-18 binding protein (IL-18bp). We, therefore, designed a prospective, longitudinal cohort study to examine IL-18 negative-feedback control in relation to COVID-19 severity and mortality from symptom day 15 onwards. METHODS: 662 blood samples, matched to time from symptom onset, from 206 COVID-19 patients were analysed by enzyme-linked immunosorbent assay for IL-18 and IL-18bp, enabling calculation of free IL-18 (fIL-18) using the updated dissociation constant (Kd) of 0.05 nmol. Adjusted multivariate regression analysis was used to assess the relationship between highest fIL-18 and outcome measures of COVID-19 severity and mortality. Re-calculated fIL-18 values from a previously studied healthy cohort are also presented. RESULTS: Range of fIL-18 in COVID-19 cohort was 10.05-1157.7 pg/ml. Up to symptom day 14, mean fIL-18 levels increased in all patients. Levels in survivors declined thereafter, but remained elevated in non-survivors. Adjusted regression analysis from symptom day 15 onwards showed a 100 mmHg decrease in PaO2/FiO2 (primary outcome) for each 37.7 pg/ml increase in highest fIL-18 (p < 0.03). Per 50 pg/ml increase in highest fIL-18, adjusted logistic regression gave an odds-ratio (OR) for crude 60-day mortality of 1.41 (1.1-2.0) (p < 0.03), and an OR for death with hypoxaemic respiratory failure of 1.90 [1.3-3.1] (p < 0.01). Highest fIL-18 was associated also with organ failure in patients with hypoxaemic respiratory failure, with an increase of 63.67 pg/ml for every additional organ supported (p < 0.01). CONCLUSIONS: Elevated free IL-18 levels from symptom day 15 onwards are associated with COVID-19 severity and mortality. ISRCTN: #13450549; registration date: 30/12/2020.

5.
Nature ; 593(7857): 136-141, 2021 05.
Article in English | MEDLINE | ID: covidwho-2114170

ABSTRACT

Transmission of SARS-CoV-2 is uncontrolled in many parts of the world; control is compounded in some areas by the higher transmission potential of the B.1.1.7 variant1, which has now been reported in 94 countries. It is unclear whether the response of the virus to vaccines against SARS-CoV-2 on the basis of the prototypic strain will be affected by the mutations found in B.1.1.7. Here we assess the immune responses of individuals after vaccination with the mRNA-based vaccine BNT162b22. We measured neutralizing antibody responses after the first and second immunizations using pseudoviruses that expressed the wild-type spike protein or a mutated spike protein that contained the eight amino acid changes found in the B.1.1.7 variant. The sera from individuals who received the vaccine exhibited a broad range of neutralizing titres against the wild-type pseudoviruses that were modestly reduced against the B.1.1.7 variant. This reduction was also evident in sera from some patients who had recovered from COVID-19. Decreased neutralization of the B.1.1.7 variant was also observed for monoclonal antibodies that target the N-terminal domain (9 out of 10) and the receptor-binding motif (5 out of 31), but not for monoclonal antibodies that recognize the receptor-binding domain that bind outside the receptor-binding motif. Introduction of the mutation that encodes the E484K substitution in the B.1.1.7 background to reflect a newly emerged variant of concern (VOC 202102/02) led to a more-substantial loss of neutralizing activity by vaccine-elicited antibodies and monoclonal antibodies (19 out of 31) compared with the loss of neutralizing activity conferred by the mutations in B.1.1.7 alone. The emergence of the E484K substitution in a B.1.1.7 background represents a threat to the efficacy of the BNT162b2 vaccine.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/therapy , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/immunology , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/isolation & purification , Antibodies, Neutralizing/isolation & purification , Antibodies, Viral/isolation & purification , COVID-19/metabolism , COVID-19/virology , Female , HEK293 Cells , Humans , Immune Evasion/genetics , Immune Evasion/immunology , Immunization, Passive , Male , Middle Aged , Models, Molecular , Mutation , Neutralization Tests , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Vaccines, Synthetic/administration & dosage , COVID-19 Serotherapy
6.
Nat Commun ; 13(1): 6131, 2022 Oct 17.
Article in English | MEDLINE | ID: covidwho-2077051

ABSTRACT

Real-world data on vaccine-elicited neutralising antibody responses for two-dose AZD1222 in African populations are limited. We assessed baseline SARS-CoV-2 seroprevalence and levels of protective neutralizing antibodies prior to vaccination rollout using binding antibodies analysis coupled with pseudotyped virus neutralisation assays in two cohorts from West Africa: Nigerian healthcare workers (n = 140) and a Ghanaian community cohort (n = 527) pre and post vaccination. We found 44 and 28% of pre-vaccination participants showed IgG anti-N positivity, increasing to 59 and 39% respectively with anti-receptor binding domain (RBD) IgG-specific antibodies. Previous IgG anti-N positivity significantly increased post two-dose neutralizing antibody titres in both populations. Serological evidence of breakthrough infection was observed in 8/49 (16%). Neutralising antibodies were observed to wane in both populations, especially in anti-N negative participants with an observed waning rate of 20% highlighting the need for a combination of additional markers to characterise previous infection. We conclude that AZD1222 is immunogenic in two independent West African cohorts with high background seroprevalence and incidence of breakthrough infection in 2021. Waning titres post second dose indicates the need for booster dosing after AZD1222 in the African setting despite hybrid immunity from previous infection.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Neutralizing , Antibodies, Viral , Antibody Formation , COVID-19/epidemiology , COVID-19/prevention & control , ChAdOx1 nCoV-19 , Ghana , Humans , Immunoglobulin G , SARS-CoV-2 , Seroepidemiologic Studies , Vaccination
9.
Brain ; 145(11): 4097-4107, 2022 11 21.
Article in English | MEDLINE | ID: covidwho-2017743

ABSTRACT

COVID-19 is associated with neurological complications including stroke, delirium and encephalitis. Furthermore, a post-viral syndrome dominated by neuropsychiatric symptoms is common, and is seemingly unrelated to COVID-19 severity. The true frequency and underlying mechanisms of neurological injury are unknown, but exaggerated host inflammatory responses appear to be a key driver of COVID-19 severity. We investigated the dynamics of, and relationship between, serum markers of brain injury [neurofilament light (NfL), glial fibrillary acidic protein (GFAP) and total tau] and markers of dysregulated host response (autoantibody production and cytokine profiles) in 175 patients admitted with COVID-19 and 45 patients with influenza. During hospitalization, sera from patients with COVID-19 demonstrated elevations of NfL and GFAP in a severity-dependent manner, with evidence of ongoing active brain injury at follow-up 4 months later. These biomarkers were associated with elevations of pro-inflammatory cytokines and the presence of autoantibodies to a large number of different antigens. Autoantibodies were commonly seen against lung surfactant proteins but also brain proteins such as myelin associated glycoprotein. Commensurate findings were seen in the influenza cohort. A distinct process characterized by elevation of serum total tau was seen in patients at follow-up, which appeared to be independent of initial disease severity and was not associated with dysregulated immune responses unlike NfL and GFAP. These results demonstrate that brain injury is a common consequence of both COVID-19 and influenza, and is therefore likely to be a feature of severe viral infection more broadly. The brain injury occurs in the context of dysregulation of both innate and adaptive immune responses, with no single pathogenic mechanism clearly responsible.


Subject(s)
Brain Injuries , COVID-19 , Influenza, Human , Humans , Neurofilament Proteins , COVID-19/complications , Biomarkers , Autoantibodies , Immunity
10.
J Infect ; 85(5): 557-564, 2022 11.
Article in English | MEDLINE | ID: covidwho-2007856

ABSTRACT

OBJECTIVES: To describe the risk factors for SARS-CoV-2 infection in UK healthcare workers (HCWs). METHODS: We conducted a prospective sero-epidemiological study of HCWs at a major UK teaching hospital using a SARS-CoV-2 immunoassay. Risk factors for seropositivity were analysed using multivariate logistic regression. RESULTS: 410/5,698 (7·2%) staff tested positive for SARS-CoV-2 antibodies. Seroprevalence was higher in those working in designated COVID-19 areas compared with other areas (9·47% versus 6·16%) Healthcare assistants (aOR 2·06 [95%CI 1·14-3·71]; p=0·016) and domestic and portering staff (aOR 3·45 [95% CI 1·07-11·42]; p=0·039) had significantly higher seroprevalence than other staff groups after adjusting for age, sex, ethnicity and COVID-19 working location. Staff working in acute medicine and medical sub-specialities were also at higher risk (aOR 2·07 [95% CI 1·31-3·25]; p<0·002). Staff from Black, Asian and minority ethnic (BAME) backgrounds had an aOR of 1·65 (95% CI 1·32 - 2·07; p<0·001) compared to white staff; this increased risk was independent of COVID-19 area working. The only symptoms significantly associated with seropositivity in a multivariable model were loss of sense of taste or smell, fever, and myalgia; 31% of staff testing positive reported no prior symptoms. CONCLUSIONS: Risk of SARS-CoV-2 infection amongst HCWs is highly heterogeneous and influenced by COVID-19 working location, role, age and ethnicity. Increased risk amongst BAME staff cannot be accounted for solely by occupational factors.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19/epidemiology , Health Personnel , Hospitals, Teaching , Humans , Prospective Studies , Risk Factors , Seroepidemiologic Studies , United Kingdom/epidemiology
11.
BMC Nephrol ; 23(1): 199, 2022 05 31.
Article in English | MEDLINE | ID: covidwho-1933094

ABSTRACT

BACKGROUND: Dialysis patients and immunosuppressed renal patients are at increased risk of COVID-19 and were excluded from vaccine trials. We conducted a prospective multicentre study to assess SARS-CoV-2 vaccine antibody responses in dialysis patients and renal transplant recipients, and patients receiving immunosuppression for autoimmune disease. METHODS: Patients were recruited from three UK centres (ethics:20/EM/0180) and compared to healthy controls (ethics:17/EE/0025). SARS-CoV-2 IgG antibodies to spike protein were measured using a multiplex Luminex assay, after first and second doses of Pfizer BioNTech BNT162b2(Pfizer) or Oxford-AstraZeneca ChAdOx1nCoV-19(AZ) vaccine. RESULTS: Six hundred ninety-two patients were included (260 dialysis, 209 transplant, 223 autoimmune disease (prior rituximab 128(57%)) and 144 healthy controls. 299(43%) patients received Pfizer vaccine and 379(55%) received AZ. Following two vaccine doses, positive responses occurred in 96% dialysis, 52% transplant, 70% autoimmune patients and 100% of healthy controls. In dialysis patients, higher antibody responses were observed with the Pfizer vaccination. Predictors of poor antibody response were triple immunosuppression (adjusted odds ratio [aOR]0.016;95%CI0.002-0.13;p < 0.001) and mycophenolate mofetil (MMF) (aOR0.2;95%CI 0.1-0.42;p < 0.001) in transplant patients; rituximab within 12 months in autoimmune patients (aOR0.29;95%CI 0.008-0.096;p < 0.001) and patients receiving immunosuppression with eGFR 15-29 ml/min (aOR0.031;95%CI 0.11-0.84;p = 0.021). Lower antibody responses were associated with a higher chance of a breakthrough infection. CONCLUSIONS: Amongst dialysis, kidney transplant and autoimmune populations SARS-CoV-2 vaccine antibody responses are reduced compared to healthy controls. A reduced response to vaccination was associated with rituximab, MMF, triple immunosuppression CKD stage 4. Vaccine responses increased after the second dose, suggesting low-responder groups should be prioritised for repeated vaccination. Greater antibody responses were observed with the mRNA Pfizer vaccine compared to adenovirus AZ vaccine in dialysis patients suggesting that Pfizer SARS-CoV-2 vaccine should be the preferred vaccine choice in this sub-group.


Subject(s)
Autoimmune Diseases , COVID-19 , Viral Vaccines , BNT162 Vaccine , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Mycophenolic Acid , Renal Dialysis , Rituximab , SARS-CoV-2
12.
EBioMedicine ; 81: 104129, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1906949

ABSTRACT

BACKGROUND: There is currently no consensus on the diagnosis, definition, symptoms, or duration of COVID-19 illness. The diagnostic complexity of Long COVID is compounded in many patients who were or might have been infected with SARS-CoV-2 but not tested during the acute illness and/or are SARS-CoV-2 antibody negative. METHODS: Given the diagnostic conundrum of Long COVID, we set out to investigate SARS-CoV-2-specific T cell responses in patients with confirmed SARS-CoV-2 infection and/or Long COVID from a cohort of mostly non-hospitalised patients. FINDINGS: We discovered that IL-2 release (but not IFN-γ release) from T cells in response to SARS-CoV-2 peptides is both sensitive (75% +/-13%) and specific (88%+/-7%) for previous SARS-CoV-2 infection >6 months after a positive PCR test. We identified that 42-53% of patients with Long COVID, but without detectable SARS-CoV-2 antibodies, nonetheless have detectable SARS-CoV-2 specific T cell responses. INTERPRETATION: Our study reveals evidence (detectable T cell mediated IL-2 release) of previous SARS-CoV-2 infection in seronegative patients with Long COVID. FUNDING: This work was funded by the Addenbrooke's Charitable Trust (900276 to NS), NIHR award (G112259 to NS) and supported by the NIHR Cambridge Biomedical Research Centre. NJM is supported by the MRC (TSF MR/T032413/1) and NHSBT (WPA15-02). PJL is supported by the Wellcome Trust (PRF 210688/Z/18/Z, 084957/Z/08/Z), a Medical Research Council research grant MR/V011561/1 and the United Kingdom Research and a Innovation COVID Immunology Consortium grant (MR/V028448/1).


Subject(s)
COVID-19 , Antibodies, Viral , COVID-19/complications , Humans , Interleukin-2 , SARS-CoV-2 , Post-Acute COVID-19 Syndrome
13.
Nature ; 603(7902): 706-714, 2022 03.
Article in English | MEDLINE | ID: covidwho-1764186

ABSTRACT

The SARS-CoV-2 Omicron BA.1 variant emerged in 20211 and has multiple mutations in its spike protein2. Here we show that the spike protein of Omicron has a higher affinity for ACE2 compared with Delta, and a marked change in its antigenicity increases Omicron's evasion of therapeutic monoclonal and vaccine-elicited polyclonal neutralizing antibodies after two doses. mRNA vaccination as a third vaccine dose rescues and broadens neutralization. Importantly, the antiviral drugs remdesivir and molnupiravir retain efficacy against Omicron BA.1. Replication was similar for Omicron and Delta virus isolates in human nasal epithelial cultures. However, in lung cells and gut cells, Omicron demonstrated lower replication. Omicron spike protein was less efficiently cleaved compared with Delta. The differences in replication were mapped to the entry efficiency of the virus on the basis of spike-pseudotyped virus assays. The defect in entry of Omicron pseudotyped virus to specific cell types effectively correlated with higher cellular RNA expression of TMPRSS2, and deletion of TMPRSS2 affected Delta entry to a greater extent than Omicron. Furthermore, drug inhibitors targeting specific entry pathways3 demonstrated that the Omicron spike inefficiently uses the cellular protease TMPRSS2, which promotes cell entry through plasma membrane fusion, with greater dependency on cell entry through the endocytic pathway. Consistent with suboptimal S1/S2 cleavage and inability to use TMPRSS2, syncytium formation by the Omicron spike was substantially impaired compared with the Delta spike. The less efficient spike cleavage of Omicron at S1/S2 is associated with a shift in cellular tropism away from TMPRSS2-expressing cells, with implications for altered pathogenesis.


Subject(s)
COVID-19/pathology , COVID-19/virology , Membrane Fusion , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Serine Endopeptidases/metabolism , Virus Internalization , Adult , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19 Vaccines/immunology , Cell Line , Cell Membrane/metabolism , Cell Membrane/virology , Chlorocebus aethiops , Convalescence , Female , Humans , Immune Sera/immunology , Intestines/pathology , Intestines/virology , Lung/pathology , Lung/virology , Male , Middle Aged , Mutation , Nasal Mucosa/pathology , Nasal Mucosa/virology , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Tissue Culture Techniques , Virulence , Virus Replication
14.
PLoS Pathog ; 18(2): e1010265, 2022 02.
Article in English | MEDLINE | ID: covidwho-1686115

ABSTRACT

Efforts to define serological correlates of protection against COVID-19 have been hampered by the lack of a simple, scalable, standardised assay for SARS-CoV-2 infection and antibody neutralisation. Plaque assays remain the gold standard, but are impractical for high-throughput screening. In this study, we show that expression of viral proteases may be used to quantitate infected cells. Our assays exploit the cleavage of specific oligopeptide linkers, leading to the activation of cell-based optical biosensors. First, we characterise these biosensors using recombinant SARS-CoV-2 proteases. Next, we confirm their ability to detect viral protease expression during replication of authentic virus. Finally, we generate reporter cells stably expressing an optimised luciferase-based biosensor, enabling viral infection to be measured within 24 h in a 96- or 384-well plate format, including variants of concern. We have therefore developed a luminescent SARS-CoV-2 reporter cell line, and demonstrated its utility for the relative quantitation of infectious virus and titration of neutralising antibodies.


Subject(s)
Biosensing Techniques/methods , COVID-19 Testing/methods , COVID-19/virology , Luminescent Measurements/methods , Peptide Hydrolases/analysis , SARS-CoV-2/enzymology , Viral Proteins/analysis , COVID-19/diagnosis , Cell Line , Humans , Peptide Hydrolases/genetics , Peptide Hydrolases/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Viral Proteins/genetics , Viral Proteins/metabolism , Virus Replication
15.
Front Immunol ; 12: 748291, 2021.
Article in English | MEDLINE | ID: covidwho-1555236

ABSTRACT

Precision monitoring of antibody responses during the COVID-19 pandemic is increasingly important during large scale vaccine rollout and rise in prevalence of Severe Acute Respiratory Syndrome-related Coronavirus-2 (SARS-CoV-2) variants of concern (VOC). Equally important is defining Correlates of Protection (CoP) for SARS-CoV-2 infection and COVID-19 disease. Data from epidemiological studies and vaccine trials identified virus neutralising antibodies (Nab) and SARS-CoV-2 antigen-specific (notably RBD and S) binding antibodies as candidate CoP. In this study, we used the World Health Organisation (WHO) international standard to benchmark neutralising antibody responses and a large panel of binding antibody assays to compare convalescent sera obtained from: a) COVID-19 patients; b) SARS-CoV-2 seropositive healthcare workers (HCW) and c) seronegative HCW. The ultimate aim of this study is to identify biomarkers of humoral immunity that could be used to differentiate severe from mild or asymptomatic SARS-CoV-2 infections. Some of these biomarkers could be used to define CoP in further serological studies using samples from vaccination breakthrough and/or re-infection cases. Whenever suitable, the antibody levels of the samples studied were expressed in International Units (IU) for virus neutralisation assays or in Binding Antibody Units (BAU) for ELISA tests. In this work we used commercial and non-commercial antibody binding assays; a lateral flow test for detection of SARS-CoV-2-specific IgG/IgM; a high throughput multiplexed particle flow cytometry assay for SARS-CoV-2 Spike (S), Nucleocapsid (N) and Receptor Binding Domain (RBD) proteins); a multiplex antigen semi-automated immuno-blotting assay measuring IgM, IgA and IgG; a pseudotyped microneutralisation test (pMN) and an electroporation-dependent neutralisation assay (EDNA). Our results indicate that overall, severe COVID-19 patients showed statistically significantly higher levels of SARS-CoV-2-specific neutralising antibodies (average 1029 IU/ml) than those observed in seropositive HCW with mild or asymptomatic infections (379 IU/ml) and that clinical severity scoring, based on WHO guidelines was tightly correlated with neutralisation and RBD/S antibodies. In addition, there was a positive correlation between severity, N-antibody assays and intracellular virus neutralisation.


Subject(s)
COVID-19/immunology , Convalescence , Immunity, Humoral , SARS-CoV-2/immunology , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Antigens, Viral/immunology , Biomarkers/blood , COVID-19/blood , COVID-19/diagnosis , COVID-19 Serological Testing/standards , Calibration , Humans , Immunoglobulin Isotypes/blood , Immunoglobulin Isotypes/immunology , Reference Standards , Severity of Illness Index
16.
J Crit Care Med (Targu Mures) ; 7(3): 199-210, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1496898

ABSTRACT

INTRODUCTION: In early 2020, at first surge of the coronavirus disease 2019 (COVID-19) pandemic, many health care workers (HCW) were re-deployed to critical care environments to support intensive care teams looking after patients with severe COVID-19. There was considerable anxiety of increased risk of COVID-19 for these staff. To determine whether critical care HCW were at increased risk of hospital acquired infection, we explored the relationship between workplace, patient facing role and evidence of immune exposure to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within a quaternary hospital providing a regional critical care response. Routine viral surveillance was not available at this time. METHODS: We screened over 500 HCW (25% of the total workforce) for history of clinical symptoms of possible COVID19, assigning a symptom severity score, and quantified SARS-CoV-2 serum antibodies as evidence of immune exposure to the virus. RESULTS: Whilst 45% of the cohort reported symptoms that they consider may have represented COVID-19, 14% had evidence of immune exposure. Staffs in patient facing critical care roles were least likely to be seropositive (9%) and staff working in non-patient facing roles most likely to be seropositive (22%). Anosmia and fever were the most discriminating symptoms for seropositive status. Older males presented with more severe symptoms. Of the 12 staff screened positive by nasal swab (10 symptomatic), 3 showed no evidence of seroconversion in convalescence. CONCLUSIONS: Patient facing staff working in critical care do not appear to be at increased risk of hospital acquired infection however the risk of nosocomial infection from non-patient facing staff may be more significant than previous recognised. Most symptoms ascribed to possible COVID-19 were found to have no evidence of immune exposure however seroprevalence may underrepresent infection frequency. Older male staff were at the greatest risk of more severe symptoms.

18.
Nature ; 592(7853): 277-282, 2021 04.
Article in English | MEDLINE | ID: covidwho-1387425

ABSTRACT

The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for virus infection through the engagement of the human ACE2 protein1 and is a major antibody target. Here we show that chronic infection with SARS-CoV-2 leads to viral evolution and reduced sensitivity to neutralizing antibodies in an immunosuppressed individual treated with convalescent plasma, by generating whole-genome ultra-deep sequences for 23 time points that span 101 days and using in vitro techniques to characterize the mutations revealed by sequencing. There was little change in the overall structure of the viral population after two courses of remdesivir during the first 57 days. However, after convalescent plasma therapy, we observed large, dynamic shifts in the viral population, with the emergence of a dominant viral strain that contained a substitution (D796H) in the S2 subunit and a deletion (ΔH69/ΔV70) in the S1 N-terminal domain of the spike protein. As passively transferred serum antibodies diminished, viruses with the escape genotype were reduced in frequency, before returning during a final, unsuccessful course of convalescent plasma treatment. In vitro, the spike double mutant bearing both ΔH69/ΔV70 and D796H conferred modestly decreased sensitivity to convalescent plasma, while maintaining infectivity levels that were similar to the wild-type virus.The spike substitution mutant D796H appeared to be the main contributor to the decreased susceptibility to neutralizing antibodies, but this mutation resulted in an infectivity defect. The spike deletion mutant ΔH69/ΔV70 had a twofold higher level of infectivity than wild-type SARS-CoV-2, possibly compensating for the reduced infectivity of the D796H mutation. These data reveal strong selection on SARS-CoV-2 during convalescent plasma therapy, which is associated with the emergence of viral variants that show evidence of reduced susceptibility to neutralizing antibodies in immunosuppressed individuals.


Subject(s)
COVID-19 Drug Treatment , COVID-19/therapy , COVID-19/virology , Evolution, Molecular , Mutagenesis/drug effects , SARS-CoV-2/drug effects , SARS-CoV-2/genetics , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Adenosine Monophosphate/therapeutic use , Aged , Alanine/analogs & derivatives , Alanine/pharmacology , Alanine/therapeutic use , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Chronic Disease , Genome, Viral/drug effects , Genome, Viral/genetics , High-Throughput Nucleotide Sequencing , Humans , Immune Evasion/drug effects , Immune Evasion/genetics , Immune Evasion/immunology , Immune Tolerance/drug effects , Immune Tolerance/immunology , Immunization, Passive , Immunosuppression Therapy , Male , Mutant Proteins/chemistry , Mutant Proteins/genetics , Mutant Proteins/immunology , Mutation , Phylogeny , SARS-CoV-2/immunology , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Time Factors , Viral Load/drug effects , Virus Shedding , COVID-19 Serotherapy
19.
J Virol ; 95(15): e0020321, 2021 07 12.
Article in English | MEDLINE | ID: covidwho-1305505

ABSTRACT

The majority of SARS-CoV-2 vaccines in use or advanced development are based on the viral spike protein (S) as their immunogen. S is present on virions as prefusion trimers in which the receptor binding domain (RBD) is stochastically open or closed. Neutralizing antibodies have been described against both open and closed conformations. The long-term success of vaccination strategies depends upon inducing antibodies that provide long-lasting broad immunity against evolving SARS-CoV-2 strains. Here, we have assessed the results of immunization in a mouse model using an S protein trimer stabilized in the closed state to prevent full exposure of the receptor binding site and therefore interaction with the receptor. We compared this with other modified S protein constructs, including representatives used in current vaccines. We found that all trimeric S proteins induced a T cell response and long-lived, strongly neutralizing antibody responses against 2019 SARS-CoV-2 and variants of concern P.1 and B.1.351. Notably, the protein binding properties of sera induced by the closed spike differed from those induced by standard S protein constructs. Closed S proteins induced more potent neutralizing responses than expected based on the degree to which they inhibit interactions between the RBD and ACE2. These observations suggest that closed spikes recruit different, but equally potent, immune responses than open spikes and that this is likely to include neutralizing antibodies against conformational epitopes present in the closed conformation. We suggest that closed spikes, together with their improved stability and storage properties, may be a valuable component of refined, next-generation vaccines. IMPORTANCE Vaccines in use against SARS-CoV-2 induce immune responses against the spike protein. There is intense interest in whether the antibody response induced by vaccines will be robust against new variants, as well as in next-generation vaccines for use in previously infected or immunized individuals. We assessed the use as an immunogen of a spike protein engineered to be conformationally stabilized in the closed state where the receptor binding site is occluded. Despite occlusion of the receptor binding site, the spike induces potently neutralizing sera against multiple SARS-CoV-2 variants. Antibodies are raised against a different pattern of epitopes to those induced by other spike constructs, preferring conformational epitopes present in the closed conformation. Closed spikes, or mRNA vaccines based on their sequence, can be a valuable component of next-generation vaccines.


Subject(s)
Angiotensin-Converting Enzyme 2 , Antibodies, Neutralizing , Antibodies, Viral , Epitopes , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/immunology , Animals , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/immunology , Antibodies, Viral/chemistry , Antibodies, Viral/immunology , COVID-19 Vaccines/chemistry , COVID-19 Vaccines/immunology , Epitopes/chemistry , Epitopes/immunology , HEK293 Cells , Humans , Mice , Protein Stability , SARS-CoV-2/chemistry , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology
20.
Nature ; 596(7872): 417-422, 2021 08.
Article in English | MEDLINE | ID: covidwho-1287811

ABSTRACT

Although two-dose mRNA vaccination provides excellent protection against SARS-CoV-2, there is little information about vaccine efficacy against variants of concern (VOC) in individuals above eighty years of age1. Here we analysed immune responses following vaccination with the BNT162b2 mRNA vaccine2 in elderly participants and younger healthcare workers. Serum neutralization and levels of binding IgG or IgA after the first vaccine dose were lower in older individuals, with a marked drop in participants over eighty years old. Sera from participants above eighty showed lower neutralization potency against the B.1.1.7 (Alpha), B.1.351 (Beta) and P.1. (Gamma) VOC than against the wild-type virus and were more likely to lack any neutralization against VOC following the first dose. However, following the second dose, neutralization against VOC was detectable regardless of age. The frequency of SARS-CoV-2 spike-specific memory B cells was higher in elderly responders (whose serum showed neutralization activity) than in non-responders after the first dose. Elderly participants showed a clear reduction in somatic hypermutation of class-switched cells. The production of interferon-γ and interleukin-2 by SARS-CoV-2 spike-specific T cells was lower in older participants, and both cytokines were secreted primarily by CD4 T cells. We conclude that the elderly are a high-risk population and that specific measures to boost vaccine responses in this population are warranted, particularly where variants of concern are circulating.


Subject(s)
Aging/immunology , COVID-19 Vaccines/immunology , Immunity , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Aging/blood , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Autoantibodies/immunology , B-Lymphocytes/cytology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , BNT162 Vaccine , COVID-19 Vaccines/administration & dosage , Female , Health Personnel , Humans , Immunity/genetics , Immunization, Secondary , Immunoglobulin A/immunology , Immunoglobulin Class Switching , Immunoglobulin G/genetics , Immunoglobulin G/immunology , Immunologic Memory/immunology , Inflammation/blood , Inflammation/immunology , Interferon-gamma/immunology , Interleukin-2/immunology , Male , Middle Aged , Somatic Hypermutation, Immunoglobulin , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes/immunology , Vaccination , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/immunology
SELECTION OF CITATIONS
SEARCH DETAIL