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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-338394

ABSTRACT

Movement and contacts are central to the transmission of infectious diseases and, within the hospital setting, healthcare worker (HCW) mobility and their contact with patients play an important role in the spread of nosocomial disease. Yet data relating to HCW behaviours associated with mobility and contacts in the healthcare environment are often limited. This paper proposes a framework for integrating several electronic data sources routinely-collected by modern hospitals, to enable the measurement of HCW behaviours relevant to the transmission of infections. Using data from a London teaching hospital during the COVID-19 pandemic, we demonstrate how, at an aggregate level, electronic medical records (EMRs) and door access logs can be used to establish changes in HCW mobility and patient contacts. In addition, to show the utility of these data sources in supporting infection prevention and control (IPC), we investigate changes in the indirect connectivity of patients (resulting from shared contacts with HCWs) and spatial connectivity of floors (owing to the movements of HCWs). Average daily rates of patient contacts are computed and found to be higher throughout the pandemic compared to that pre-pandemic, while the average daily rates of HCW mobility remained stable until the second wave, where they surpassed pre-pandemic levels. The response of HCW behaviour to the pandemic was not equal between floors, whereby the highest increases in patient contacts and mobility were on floors handling the majority of COVID-19 patients. The first wave of COVID-19 patients resulted in changes to the flow of HCWs between floors, but the interconnectivity between COVID-19 and non COVID-19 wards was evident throughout the pandemic. Daily rates of indirect contact between patients provided evidence for reactive staff cohorting, whereby indirect contact rates between COVID-19 positive and negative patients were lowest during peaks in COVID-19 hospital admissions. We propose that IPC practitioners use these routinely collected data on HCW behaviour to support infection control activities and to help better protect hospital staff and patients from nosocomial outbreaks of communicable diseases.

2.
Front Public Health ; 9: 665584, 2021.
Article in English | MEDLINE | ID: covidwho-1771099

ABSTRACT

Background: ODK provides software and standards that are popular solutions for off-grid electronic data collection and has substantial code overlap and interoperability with a number of related software products including CommCare, Enketo, Ona, SurveyCTO, and KoBoToolbox. These tools provide open-source options for off-grid use in public health data collection, management, analysis, and reporting. During the 2018-2020 Ebola epidemic in the North Kivu and Ituri regions of Democratic Republic of Congo, we used these tools to support the DRC Ministère de la Santé RDC and World Health Organization in their efforts to administer an experimental vaccine (VSV-Zebov-GP) as part of their strategy to control the transmission of infection. Method: New functions were developed to facilitate the use of ODK, Enketo and R in large scale data collection, aggregation, monitoring, and near-real-time analysis during clinical research in health emergencies. We present enhancements to ODK that include a built-in audit-trail, a framework and companion app for biometric registration of ISO/IEC 19794-2 fingerprint templates, enhanced performance features, better scalability for studies featuring millions of data form submissions, increased options for parallelization of research projects, and pipelines for automated management and analysis of data. We also developed novel encryption protocols for enhanced web-form security in Enketo. Results: Against the backdrop of a complex and challenging epidemic response, our enhanced platform of open tools was used to collect and manage data from more than 280,000 eligible study participants who received VSV-Zebov-GP under informed consent. These data were used to determine whether the VSV-Zebov-GP was safe and effective and to guide daily field operations. Conclusions: We present open-source developments that make electronic data management during clinical research and health emergencies more viable and robust. These developments will also enhance and expand the functionality of a diverse range of data collection platforms that are based on the ODK software and standards.


Subject(s)
Epidemics , Hemorrhagic Fever, Ebola , Data Management , Electronics , Epidemics/prevention & control , Hemorrhagic Fever, Ebola/epidemiology , Hemorrhagic Fever, Ebola/prevention & control , Humans
3.
Clin Infect Dis ; 2021 Sep 06.
Article in English | MEDLINE | ID: covidwho-1706197

ABSTRACT

BACKGROUND: The SARS-CoV-2 alpha variant (B.1.1.7) is associated with higher transmissibility than wild type virus, becoming the dominant variant in England by January 2021. We aimed to describe the severity of the alpha variant in terms of the pathway of disease from testing positive to hospital admission and death. METHODS: With the approval of NHS England, we linked individual-level data from primary care with SARS-CoV-2 community testing, hospital admission, and ONS all-cause death data. We used testing data with S-gene target failure as a proxy for distinguishing alpha and wild-type cases, and stratified Cox proportional hazards regression to compare the relative severity of alpha cases compared to wild type diagnosed from 16th November 2020 to 11th January 2021. RESULTS: Using data from 185,234 people who tested positive for SARS-CoV-2 in the community (alpha=93,153; wild-type=92,081), in fully adjusted analysis accounting for individual-level demographics and comorbidities as well as regional variation in infection incidence, we found alpha associated with 73% higher hazards of all-cause death (aHR: 1.73 (95% CI 1.41 - 2.13; P<.0001)) and 62% higher hazards of hospital admission (aHR: 1.62 ((95% CI 1.48 - 1.78; P<.0001), compared to wild-type virus. Among patients already admitted to ICU, the association between alpha and increased all-cause mortality was smaller and the confidence interval included the null (aHR: 1.20 (95% CI 0.74 - 1.95; P=0.45)). CONCLUSIONS: The SARS-CoV-2 alpha variant is associated with an increased risk of both hospitalisation and mortality than wild-type virus.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-305830

ABSTRACT

Background: For a targeted therapeutic strategy to show outcome benefit, there needs to be a strong biological and pathogenic rationale to underpin and direct personalised treatments. Relevant biological disease features and biomarkers identify patients for the correct therapeutic, delivered at an appropriate time, dose and duration for maximal efficacy. We evaluated whether serum levels of a wide range of proposed therapeutic targets in COVID-19 discriminated between patients with mild and severe disease or death.Methods: A search of clinicaltrials.gov identified immunological drug targets in COVID-19. We subsequently conducted an observational study investigating the association of serum biomarkers relating to putative therapeutic biomarkers with illness severity and outcome.Results: A search of clinicaltrials.gov identified 477 randomized trials assessing immunomodulatory therapies, including 168 different therapies against 83 different pathways. We measured levels of ten cytokines/signalling proteins including those related to the most common therapeutic targets (GM-CSF, IFN-α2a, IFN-β, IFN-γ, IL-1β, IL-1ra, IL-6, IL-7, IL-8, TNF-α), immunoglobulin G ( IgG) antibodies directed against either the COVID-19 spike protein (S1) or nucleocapsid protein (N), and neutralization titres of antibodies within the first 5 days of hospital admission in 86 patients, 44 (51%) with mild disease and 42 (49%) with severe disease. Six of the ten cytokine/signalling protein markers measured (IL-6, IL-7, IL-8, interferon- a, interferon- b, IL -1ra ) discriminated between patients with mild and severe disease, although most were similar or only modestly raised above that seen in healthy volunteers. A similar proportion of patients with mild or severe disease had detectable S1 or N IgG antibodies with equivalent levels between groups. Neutralization titres were higher among patients with severe disease.Interpretation: Some therapeutic and prognostic biomarkers may be potentially useful in identifying patients who may benefit from specific immunomodulatory therapies in COVID-19 disease, particularly interleukin-6. It is however noteworthy that absolute values of a number of identified biomarkers were either appropriately elevated or within the normal range. This implies that these immunomodulatory treatments may be of limited benefit.Funding: National Institute for Health Research UCLH Biomedical Research Centre (BRC756/HI/MS/101440) and the UCL Coronavirus Response Fund.Declaration of Interests: MeS reports grants and advisory board fees from NewB, grants from the Defence Science and Technology Laboratory, Critical Pressure, Apollo Therapeutics, advisory board and speaker fees (paid to his institution) from Amormed, Biotest, GE, Baxter, Roche, and Bayer, and honorarium for chairing a data monitoring and safety committee from Shionogi. All other authors have nothing to declare. Ethics Approval Statement: Ethical approval was received from the London-Westminster Research Ethics Committee, the Health Research Authority and Health and Care Research Wales (HCRW) on 2nd July 2020 (REC reference 20/HRA/2505, IRAS ID 284088). The SAFER study protocol was approved by the NHS Health Research Authority (ref 20/SC/0147) on 26 March 2020. Ethical oversight was provided by the South- Central Berkshire Research Ethics Committee.

5.
J Neurochem ; 161(2): 146-157, 2022 04.
Article in English | MEDLINE | ID: covidwho-1673193

ABSTRACT

SARS-CoV-2 infection can damage the nervous system with multiple neurological manifestations described. However, there is limited understanding of the mechanisms underlying COVID-19 neurological injury. This is a cross-sectional exploratory prospective biomarker cohort study of 21 patients with COVID-19 neurological syndromes (Guillain-Barre Syndrome [GBS], encephalitis, encephalopathy, acute disseminated encephalomyelitis [ADEM], intracranial hypertension, and central pain syndrome) and 23 healthy COVID-19 negative controls. We measured cerebrospinal fluid (CSF) and serum biomarkers of amyloid processing, neuronal injury (neurofilament light), astrocyte activation (GFAp), and neuroinflammation (tissue necrosis factor [TNF] ɑ, interleukin [IL]-6, IL-1ß, IL-8). Patients with COVID-19 neurological syndromes had significantly reduced CSF soluble amyloid precursor protein (sAPP)-ɑ (p = 0.004) and sAPPß (p = 0.03) as well as amyloid ß (Aß) 40 (p = 5.2 × 10-8 ), Aß42 (p = 3.5 × 10-7 ), and Aß42/Aß40 ratio (p = 0.005) compared to controls. Patients with COVID-19 neurological syndromes showed significantly increased neurofilament light (NfL, p = 0.001) and this negatively correlated with sAPPɑ and sAPPß. Conversely, GFAp was significantly reduced in COVID-19 neurological syndromes (p = 0.0001) and this positively correlated with sAPPɑ and sAPPß. COVID-19 neurological patients also displayed significantly increased CSF proinflammatory cytokines and these negatively correlated with sAPPɑ and sAPPß. A sensitivity analysis of COVID-19-associated GBS revealed a non-significant trend toward greater impairment of amyloid processing in COVID-19 central than peripheral neurological syndromes. This pilot study raises the possibility that patients with COVID-19-associated neurological syndromes exhibit impaired amyloid processing. Altered amyloid processing was linked to neuronal injury and neuroinflammation but reduced astrocyte activation.


Subject(s)
Alzheimer Disease , Amyloidosis , COVID-19 , Alzheimer Disease/cerebrospinal fluid , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/cerebrospinal fluid , Biomarkers/cerebrospinal fluid , COVID-19/complications , Cohort Studies , Cross-Sectional Studies , Humans , Pilot Projects , Prospective Studies , SARS-CoV-2
8.
Encyclopedia of Respiratory Medicine (Second Edition) ; : 231-242, 2022.
Article in English | ScienceDirect | ID: covidwho-1415138

ABSTRACT

COVID-19, caused by SARS-CoV-2, is an emerging viral respiratory pathogen. The disease was first described in China in 2019, likely emerging as a zoonosis, before spreading worldwide to cause a severe global pandemic in 2020. COVID-19 is transmitted person to person, predominantly by droplet spread. COVID-19 causes a wide spectrum of clinical illness ranging from asymptomatic infection, to a mild self-limiting illness. A small proportion of individuals will go on to develop a more severe respiratory illness which may be complicated by acute respiratory distress syndrome. The majority of individuals will make a full recovery but a minority of patients will have a more severe outcome. Age is the strongest predictor of outcomes with mortality increasing to 15% or higher among those aged 80years or older. Treatment options for COVID-19 continue to evolve. The strongest current evidence is the use of systemic corticosteroids which reduce mortality in patients with moderate to severe COVID-19. Given the epidemic nature of COVID-19 early surge planning and expansion of both staff and bed base capacity are critical. At the time of writing a number of promising COVID-19 vaccines have been developed but the long term impact of these vaccines on the pandemic is uncertain.

9.
Med (N Y) ; 2(9): 1093-1109.e6, 2021 09 10.
Article in English | MEDLINE | ID: covidwho-1404795

ABSTRACT

BACKGROUND: Differences in humoral immunity to coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), between children and adults remain unexplained, and the effect of underlying immune dysfunction or suppression is unknown. Here, we sought to examine the antibody immune competence of children and adolescents with prevalent inflammatory rheumatic diseases, juvenile idiopathic arthritis (JIA), juvenile dermatomyositis (JDM), and juvenile systemic lupus erythematosus (JSLE) against the seasonal human coronavirus (HCoV)-OC43 that frequently infects this age group. METHODS: Sera were collected from JIA (n = 118), JDM (n = 49), and JSLE (n = 30) patients and from healthy control (n = 54) children and adolescents prior to the coronavirus disease 19 (COVID-19) pandemic. We used sensitive flow-cytometry-based assays to determine titers of antibodies that reacted with the spike and nucleoprotein of HCoV-OC43 and cross-reacted with the spike and nucleoprotein of SARS-CoV-2, and we compared them with respective titers in sera from patients with multisystem inflammatory syndrome in children and adolescents (MIS-C). FINDINGS: Despite immune dysfunction and immunosuppressive treatment, JIA, JDM, and JSLE patients maintained comparable or stronger humoral responses than healthier peers, which was dominated by immunoglobulin G (IgG) antibodies to HCoV-OC43 spike, and harbored IgG antibodies that cross-reacted with SARS-CoV-2 spike. In contrast, responses to HCoV-OC43 and SARS-CoV-2 nucleoproteins exhibited delayed age-dependent class-switching and were not elevated in JIA, JDM, and JSLE patients, which argues against increased exposure. CONCLUSIONS: Consequently, autoimmune rheumatic diseases and their treatment were associated with a favorable ratio of spike to nucleoprotein antibodies. FUNDING: This work was supported by a Centre of Excellence Centre for Adolescent Rheumatology Versus Arthritis grant, 21593, UKRI funding reference MR/R013926/1, the Great Ormond Street Children's Charity, Cure JM Foundation, Myositis UK, Lupus UK, and the NIHR Biomedical Research Centres at GOSH and UCLH. This work was supported by the Francis Crick Institute, which receives its core funding from Cancer Research UK, the UK Medical Research Council, and the Wellcome Trust.


Subject(s)
Autoimmune Diseases , COVID-19 , Coronavirus OC43, Human , Rheumatic Diseases , Adolescent , Adult , Antibodies, Viral , Antibody Formation , COVID-19/complications , Child , Humans , Immunoglobulin G , Nucleoproteins , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Systemic Inflammatory Response Syndrome
10.
Clin Infect Dis ; 2021 Sep 06.
Article in English | MEDLINE | ID: covidwho-1393220

ABSTRACT

BACKGROUND: The SARS-CoV-2 alpha variant (B.1.1.7) is associated with higher transmissibility than wild type virus, becoming the dominant variant in England by January 2021. We aimed to describe the severity of the alpha variant in terms of the pathway of disease from testing positive to hospital admission and death. METHODS: With the approval of NHS England, we linked individual-level data from primary care with SARS-CoV-2 community testing, hospital admission, and ONS all-cause death data. We used testing data with S-gene target failure as a proxy for distinguishing alpha and wild-type cases, and stratified Cox proportional hazards regression to compare the relative severity of alpha cases compared to wild type diagnosed from 16th November 2020 to 11th January 2021. RESULTS: Using data from 185,234 people who tested positive for SARS-CoV-2 in the community (alpha=93,153; wild-type=92,081), in fully adjusted analysis accounting for individual-level demographics and comorbidities as well as regional variation in infection incidence, we found alpha associated with 73% higher hazards of all-cause death (aHR: 1.73 (95% CI 1.41 - 2.13; P<.0001)) and 62% higher hazards of hospital admission (aHR: 1.62 ((95% CI 1.48 - 1.78; P<.0001), compared to wild-type virus. Among patients already admitted to ICU, the association between alpha and increased all-cause mortality was smaller and the confidence interval included the null (aHR: 1.20 (95% CI 0.74 - 1.95; P=0.45)). CONCLUSIONS: The SARS-CoV-2 alpha variant is associated with an increased risk of both hospitalisation and mortality than wild-type virus.

12.
Brain Commun ; 3(3): fcab099, 2021.
Article in English | MEDLINE | ID: covidwho-1358433

ABSTRACT

Preliminary pathological and biomarker data suggest that SARS-CoV-2 infection can damage the nervous system. To understand what, where and how damage occurs, we collected serum and CSF from patients with COVID-19 and characterized neurological syndromes involving the PNS and CNS (n = 34). We measured biomarkers of neuronal damage and neuroinflammation, and compared these with non-neurological control groups, which included patients with (n = 94) and without (n = 24) COVID-19. We detected increased concentrations of neurofilament light, a dynamic biomarker of neuronal damage, in the CSF of those with CNS inflammation (encephalitis and acute disseminated encephalomyelitis) [14 800 pg/ml (400, 32 400)], compared to those with encephalopathy [1410 pg/ml (756, 1446)], peripheral syndromes (Guillain-Barré syndrome) [740 pg/ml (507, 881)] and controls [872 pg/ml (654, 1200)]. Serum neurofilament light levels were elevated across patients hospitalized with COVID-19, irrespective of neurological manifestations. There was not the usual close correlation between CSF and serum neurofilament light, suggesting serum neurofilament light elevation in the non-neurological patients may reflect peripheral nerve damage in response to severe illness. We did not find significantly elevated levels of serum neurofilament light in community cases of COVID-19 arguing against significant neurological damage. Glial fibrillary acidic protein, a marker of astrocytic activation, was not elevated in the CSF or serum of any group, suggesting astrocytic activation is not a major mediator of neuronal damage in COVID-19.

13.
Euro Surveill ; 26(32)2021 08.
Article in English | MEDLINE | ID: covidwho-1357496

ABSTRACT

Most reported cases of human monkeypox occur in Central and West Africa, where the causing virus is endemic. We describe the identification and public health response to an imported case of West African monkeypox from Nigeria to the United Kingdom (UK) in May 2021. Secondary transmission from the index case occurred within the family to another adult and a toddler. Concurrent COVID-19-related control measures upon arrival and at the hospital, facilitated detection and limited the number of potential contacts.


Subject(s)
COVID-19 , Monkeypox , Adult , Animals , Humans , Monkeypox/diagnosis , Monkeypox/epidemiology , Monkeypox virus , Nigeria , SARS-CoV-2 , United Kingdom/epidemiology
14.
Crit Care Explor ; 3(8): e0488, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1356719

ABSTRACT

OBJECTIVES: Multiple mechanisms have been proposed to explain disease severity in coronavirus disease 2019. Therapeutic approaches need to be underpinned by sound biological rationale. We evaluated whether serum levels of a range of proposed coronavirus disease 2019 therapeutic targets discriminated between patients with mild or severe disease. DESIGN: A search of ClinicalTrials.gov identified coronavirus disease 2019 immunological drug targets. We subsequently conducted a retrospective observational cohort study investigating the association of serum biomarkers within the first 5 days of hospital admission relating to putative therapeutic biomarkers with illness severity and outcome. SETTING: University College London, a tertiary academic medical center in the United Kingdom. PATIENTS: Patients admitted to hospital with a diagnosis of coronavirus disease 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eighty-six patients were recruited, 44 (51%) with mild disease and 42 (49%) with severe disease. We measured levels of 10 cytokines/signaling proteins related to the most common therapeutic targets (granulocyte-macrophage colony-stimulating factor, interferon-α2a, interferon-ß, interferon-γ, interleukin-1ß, interleukin-1 receptor antagonist, interleukin-6, interleukin-7, interleukin-8, tumor necrosis factor-α), immunoglobulin G antibodies directed against either coronavirus disease 2019 spike protein or nucleocapsid protein, and neutralization titers of antibodies. Four-hundred seventy-seven randomized trials, including 168 different therapies against 83 different pathways, were identified. Six of the 10 markers (interleukin-6, interleukin-7, interleukin-8, interferon-α2a, interferon-ß, interleukin-1 receptor antagonist) discriminated between patients with mild and severe disease, although most were similar or only modestly raised above that seen in healthy volunteers. A similar proportion of patients with mild or severe disease had detectable spike protein or nucleocapsid protein immunoglobulin G antibodies with equivalent levels between groups. Neutralization titers were higher among patients with severe disease. CONCLUSIONS: Some therapeutic and prognostic biomarkers may be useful in identifying coronavirus disease 2019 patients who may benefit from specific immunomodulatory therapies, particularly interleukin-6. However, biomarker absolute values often did not discriminate between patients with mild and severe disease or death, implying that these immunomodulatory treatments may be of limited benefit.

15.
EClinicalMedicine ; 39: 101070, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1351631

ABSTRACT

BACKGROUND: A high prevalence of antiphospholipid antibodies has been reported in case series of patients with neurological manifestations and COVID-19; however, the pathogenicity of antiphospholipid antibodies in COVID-19 neurology remains unclear. METHODS: This single-centre cross-sectional study included 106 adult patients: 30 hospitalised COVID-neurological cases, 47 non-neurological COVID-hospitalised controls, and 29 COVID-non-hospitalised controls, recruited between March and July 2020. We evaluated nine antiphospholipid antibodies: anticardiolipin antibodies [aCL] IgA, IgM, IgG; anti-beta-2 glycoprotein-1 [aß2GPI] IgA, IgM, IgG; anti-phosphatidylserine/prothrombin [aPS/PT] IgM, IgG; and anti-domain I ß2GPI (aD1ß2GPI) IgG. FINDINGS: There was a high prevalence of antiphospholipid antibodies in the COVID-neurological (73.3%) and non-neurological COVID-hospitalised controls (76.6%) in contrast to the COVID-non-hospitalised controls (48.2%). aPS/PT IgG titres were significantly higher in the COVID-neurological group compared to both control groups (p < 0.001). Moderate-high titre of aPS/PT IgG was found in 2 out of 3 (67%) patients with acute disseminated encephalomyelitis [ADEM]. aPS/PT IgG titres negatively correlated with oxygen requirement (FiO2 R=-0.15 p = 0.040) and was associated with venous thromboembolism (p = 0.043). In contrast, aCL IgA (p < 0.001) and IgG (p < 0.001) was associated with non-neurological COVID-hospitalised controls compared to the other groups and correlated positively with d-dimer and creatinine but negatively with FiO2. INTERPRETATION: Our findings show that aPS/PT IgG is associated with COVID-19-associated ADEM. In contrast, aCL IgA and IgG are seen much more frequently in non-neurological hospitalised patients with COVID-19. Characterisation of antiphospholipid antibody persistence and potential longitudinal clinical impact are required to guide appropriate management. FUNDING: This work is supported by UCL Queen Square Biomedical Research Centre (BRC) and Moorfields BRC grants (#560441 and #557595). LB is supported by a Wellcome Trust Fellowship (222102/Z/20/Z). RWP is supported by an Alzheimer's Association Clinician Scientist Fellowship (AACSF-20-685780) and the UK Dementia Research Institute. KB is supported by the Swedish Research Council (#2017-00915) and the Swedish state under the agreement between the Swedish government and the County Councils, the ALF-agreement (#ALFGBG-715986). HZ is a Wallenberg Scholar supported by grants from the Swedish Research Council (#2018-02532), the European Research Council (#681712), Swedish State Support for Clinical Research (#ALFGBG-720931), the Alzheimer Drug Discovery Foundation (ADDF), USA (#201809-2016862), and theUK Dementia Research Institute at UCL. BDM is supported by grants from the MRC/UKRI (MR/V007181/1), MRC (MR/T028750/1) and Wellcome (ISSF201902/3). MSZ, MH and RS are supported by the UCL/UCLH NIHR Biomedical Research Centre and MSZ is supported by Queen Square National Brain Appeal.

16.
Elife ; 102021 07 29.
Article in English | MEDLINE | ID: covidwho-1332333

ABSTRACT

Background: The degree of heterotypic immunity induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains is a major determinant of the spread of emerging variants and the success of vaccination campaigns, but remains incompletely understood. Methods: We examined the immunogenicity of SARS-CoV-2 variant B.1.1.7 (Alpha) that arose in the United Kingdom and spread globally. We determined titres of spike glycoprotein-binding antibodies and authentic virus neutralising antibodies induced by B.1.1.7 infection to infer homotypic and heterotypic immunity. Results: Antibodies elicited by B.1.1.7 infection exhibited significantly reduced recognition and neutralisation of parental strains or of the South Africa variant B.1.351 (Beta) than of the infecting variant. The drop in cross-reactivity was significantly more pronounced following B.1.1.7 than parental strain infection. Conclusions: The results indicate that heterotypic immunity induced by SARS-CoV-2 variants is asymmetric. Funding: This work was supported by the Francis Crick Institute and the Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/virology , SARS-CoV-2/immunology , Antibodies, Neutralizing/immunology , COVID-19/epidemiology , Cross Reactions , Humans , Parents , South Africa/epidemiology , Spike Glycoprotein, Coronavirus , United Kingdom/epidemiology
18.
BMC Med ; 19(1): 106, 2021 04 27.
Article in English | MEDLINE | ID: covidwho-1204075

ABSTRACT

BACKGROUND: Routine asymptomatic testing using RT-PCR of people who interact with vulnerable populations, such as medical staff in hospitals or care workers in care homes, has been employed to help prevent outbreaks among vulnerable populations. Although the peak sensitivity of RT-PCR can be high, the probability of detecting an infection will vary throughout the course of an infection. The effectiveness of routine asymptomatic testing will therefore depend on testing frequency and how PCR detection varies over time. METHODS: We fitted a Bayesian statistical model to a dataset of twice weekly PCR tests of UK healthcare workers performed by self-administered nasopharyngeal swab, regardless of symptoms. We jointly estimated times of infection and the probability of a positive PCR test over time following infection; we then compared asymptomatic testing strategies by calculating the probability that a symptomatic infection is detected before symptom onset and the probability that an asymptomatic infection is detected within 7 days of infection. RESULTS: We estimated that the probability that the PCR test detected infection peaked at 77% (54-88%) 4 days after infection, decreasing to 50% (38-65%) by 10 days after infection. Our results suggest a substantially higher probability of detecting infections 1-3 days after infection than previously published estimates. We estimated that testing every other day would detect 57% (33-76%) of symptomatic cases prior to onset and 94% (75-99%) of asymptomatic cases within 7 days if test results were returned within a day. CONCLUSIONS: Our results suggest that routine asymptomatic testing can enable detection of a high proportion of infected individuals early in their infection, provided that the testing is frequent and the time from testing to notification of results is sufficiently fast.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Polymerase Chain Reaction/methods , Bayes Theorem , COVID-19/pathology , Female , Humans , Male
19.
Lancet Infect Dis ; 21(9): 1246-1256, 2021 09.
Article in English | MEDLINE | ID: covidwho-1180123

ABSTRACT

BACKGROUND: Emergence of variants with specific mutations in key epitopes in the spike protein of SARS-CoV-2 raises concerns pertinent to mass vaccination campaigns and use of monoclonal antibodies. We aimed to describe the emergence of the B.1.1.7 variant of concern (VOC), including virological characteristics and clinical severity in contemporaneous patients with and without the variant. METHODS: In this cohort study, samples positive for SARS-CoV-2 on PCR that were collected from Nov 9, 2020, for patients acutely admitted to one of two hospitals on or before Dec 20, 2020, in London, UK, were sequenced and analysed for the presence of VOC-defining mutations. We fitted Poisson regression models to investigate the association between B.1.1.7 infection and severe disease (defined as point 6 or higher on the WHO ordinal scale within 14 days of symptoms or positive test) and death within 28 days of a positive test and did supplementary genomic analyses in a cohort of chronically shedding patients and in a cohort of remdesivir-treated patients. Viral load was compared by proxy, using PCR cycle threshold values and sequencing read depths. FINDINGS: Of 496 patients with samples positive for SARS-CoV-2 on PCR and who met inclusion criteria, 341 had samples that could be sequenced. 198 (58%) of 341 had B.1.1.7 infection and 143 (42%) had non-B.1.1.7 infection. We found no evidence of an association between severe disease and death and lineage (B.1.1.7 vs non-B.1.1.7) in unadjusted analyses (prevalence ratio [PR] 0·97 [95% CI 0·72-1·31]), or in analyses adjusted for hospital, sex, age, comorbidities, and ethnicity (adjusted PR 1·02 [0·76-1·38]). We detected no B.1.1.7 VOC-defining mutations in 123 chronically shedding immunocompromised patients or in 32 remdesivir-treated patients. Viral load by proxy was higher in B.1.1.7 samples than in non-B.1.1.7 samples, as measured by cycle threshold value (mean 28·8 [SD 4·7] vs 32·0 [4·8]; p=0·0085) and genomic read depth (1280 [1004] vs 831 [682]; p=0·0011). INTERPRETATION: Emerging evidence exists of increased transmissibility of B.1.1.7, and we found increased virus load by proxy for B.1.1.7 in our data. We did not identify an association of the variant with severe disease in this hospitalised cohort. FUNDING: University College London Hospitals NHS Trust, University College London/University College London Hospitals NIHR Biomedical Research Centre, Engineering and Physical Sciences Research Council.


Subject(s)
COVID-19/virology , Genome, Viral , SARS-CoV-2/genetics , Severity of Illness Index , Whole Genome Sequencing , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , London , Male , Middle Aged , Phylogeny , United Kingdom , Viral Load , Virus Shedding
20.
Cell Rep ; 34(12): 108890, 2021 03 23.
Article in English | MEDLINE | ID: covidwho-1131156

ABSTRACT

Multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines show protective efficacy, which is most likely mediated by neutralizing antibodies recognizing the viral entry protein, spike. Because new SARS-CoV-2 variants are emerging rapidly, as exemplified by the B.1.1.7, B.1.351, and P.1 lineages, it is critical to understand whether antibody responses induced by infection with the original SARS-CoV-2 virus or current vaccines remain effective. In this study, we evaluate neutralization of a series of mutated spike pseudotypes based on divergence from SARS-CoV and then compare neutralization of the B.1.1.7 spike pseudotype and individual mutations. Spike-specific monoclonal antibody neutralization is reduced dramatically; in contrast, polyclonal antibodies from individuals infected in early 2020 remain active against most mutated spike pseudotypes, but potency is reduced in a minority of samples. This work highlights that changes in SARS-CoV-2 spike can alter neutralization sensitivity and underlines the need for effective real-time monitoring of emerging mutations and their effect on vaccine efficacy.


Subject(s)
Antibodies, Neutralizing/immunology , COVID-19/virology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Antibodies, Monoclonal/genetics , Antibodies, Monoclonal/immunology , Antibodies, Viral/immunology , Antibody Formation , COVID-19/immunology , COVID-19/metabolism , COVID-19 Vaccines/immunology , HEK293 Cells , Humans , Neutralization Tests/methods , Point Mutation , Receptors, Virus/genetics , Receptors, Virus/metabolism , Spike Glycoprotein, Coronavirus/immunology
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