Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
1.
Antiviral Research ; : 105332, 2022.
Article in English | ScienceDirect | ID: covidwho-1821130

ABSTRACT

Antibodies against SARS-CoV-2 are important to generate protective immunity, with convalescent plasma one of the first therapies approved. An alternative source of polyclonal antibodies suitable for upscaling would be more amendable to regulatory approval and widespread use. In this study, sheep were immunised with SARS-CoV-2 whole spike protein or one of the subunit proteins: S1 and S2. Once substantial antibody titres were generated, plasma was collected and samples pooled for each antigen. Non-specific antibodies were removed via affinity-purification to yield candidate products for testing in a hamster model of SARS-CoV-2 infection. Affinity-purified polyclonal antibodies to whole spike, S1 and S2 proteins were evaluated for in vitro for neutralising activity against SARS-CoV-2 Wuhan-like virus (Australia/VIC01/2020) and a recent variant of concern, B.1.1.529 BA.1 (Omicron), antibody-binding, complement fixation and phagocytosis assays were also performed. All antibody preparations demonstrated an effect against SARS-CoV-2 disease in the hamster model of challenge, with those raised against the S2 subunit providing the most promise. A rapid, cost-effective therapy for COVID-19 was developed which provides a source of highly active immunoglobulin specific to SARS-CoV-2 with multi-functional activity.

2.
Transbound Emerg Dis ; 2022 Mar 25.
Article in English | MEDLINE | ID: covidwho-1765049

ABSTRACT

Following findings in Northern America of SARS-CoV-2 infections in white-tailed deer, there is concern of similar infections in European deer and their potential as reservoirs of SARS-CoV-2 including opportunities for the emergence of new variants. UK deer sera were collected in 2020-2021 from 6 species and a hybrid with 1748 tested using anti-spike and anti-nucleocapsid serology assays. No samples were positive on both assays nor by surrogate neutralization testing. There is no evidence that spill-over infections of SARS-CoV-2 occurred from the human population to UK deer or that SARS-CoV-2 has been circulating in UK deer (over the study period). Although it cannot be ruled out, study results indicate that spill-over infections followed by circulation of SARS-CoV-2 to the most common European deer species is small.

3.
Microbiol Spectr ; 10(1): e0228921, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1702730

ABSTRACT

In March 2020, the Rare and Imported Pathogens Laboratory at the UK Health Security Agency (UKHSA) (formerly Public Health England [PHE]) Porton Down, was tasked by the Department of Health and Social Care with setting up a national surveillance laboratory facility to study SARS-CoV-2 antibody responses and population-level sero-surveillance in response to the growing SARS-CoV-2 outbreak. In the following 12 months, the laboratory tested more than 160,000 samples, facilitating a wide range of research and informing UKHSA, DHSC, and UK government policy. Here we describe the implementation and use of the Euroimmun anti-SARS-CoV-2 IgG assay and provide an extended evaluation of its performance. We present a markedly improved overall sensitivity of 91.39% (≥14 days 92.74%, ≥21 days 93.59%) compared to our small-scale early study, and a specificity of 98.56%. In addition, we detail extended characteristics of the Euroimmun assay: intra- and interassay precision, correlation to neutralization, and assay linearity. IMPORTANCE Serology assays have been useful in determining those with previous SARS-CoV-2 infection in a wide range of research and serosurveillance projects. However, assays vary in their sensitivity at detecting SARS-CoV-2 antibodies. Here, we detail an extended evaluation and characterization of the Euroimmun anti-SARS-CoV-2 IgG assay, one that has been widely used within the United Kingdom on over 160,000 samples to date.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , COVID-19/blood , Immunoglobulin G/blood , SARS-CoV-2/immunology , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/virology , Humans , Public Health , Reagent Kits, Diagnostic , SARS-CoV-2/genetics , Sensitivity and Specificity , United Kingdom/epidemiology
4.
Transfusion ; 61(10): 2837-2843, 2021 10.
Article in English | MEDLINE | ID: covidwho-1360538

ABSTRACT

BACKGROUND: Convalescent plasma (CP) therapy for coronavirus disease (COVID-19) provides virus-neutralizing antibodies that may ameliorate the outcome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. The effectiveness of CP likely depends on its antiviral neutralizing potency and is determined using in vitro neutralizing antibody assays. STUDY DESIGN AND METHODS: We evaluated abilities of three immunoassays for anti-spike antibodies (EUROimmun, Ortho, Roche), a pseudotype-based neutralization assay, and two assays that quantify ACE2 binding of spike protein (GenScript and hemagglutination test [HAT]-based assay) to predict neutralizing antibody titers in 113 CP donations. Assay outputs were analyzed through linear regression and calculation of sensitivities and specificities by receiver operator characteristic (ROC) analysis. RESULTS: Median values of plasma samples containing neutralizing antibodies produced conversion factors for assay unitage of ×6.5 (pseudotype), ×19 (GenScript), ×3.4 (HAT assay), ×0.08 (EUROimmun), ×1.64 (Roche), and ×0.10 (Ortho). All selected assays were sufficient in identifying the high titer donations based on ROC analysis; area over curve ranged from 91.7% for HAT and GenScript assay to 95.6% for pseudotype assay. However, their ability to predict the actual neutralizing antibody levels varied substantially as shown by linear regression correlation values (from 0.27 for Ortho to 0.61 for pseudotype assay). DISCUSSION: Overall, the study data demonstrate that all selected assays were effective in identifying donations with high neutralizing antibody levels and are potentially suitable as surrogate assays for donation selection for CP therapy.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 Serological Testing/methods , Immunoassay/methods , SARS-CoV-2/immunology , COVID-19/therapy , Humans , Immunization, Passive , Neutralization Tests
5.
J Infect ; 83(2): 237-279, 2021 08.
Article in English | MEDLINE | ID: covidwho-1225296

ABSTRACT

The COVID-19 vaccination programme commenced in England on 8th December 2020 primarily based on age; by 7th March 2021 approximately 93% of the English population aged 70+ years had received at least 1 dose of either the Pfizer BioNTech or AstraZeneca vaccines. Using a nucleoprotein assay that detects antibodies following natural infection only and a spike assay that detects infection and vaccine-induced responses, we aim to describe the impact of vaccination on SARS-CoV-2 antibody prevalence in English blood donors.


Subject(s)
COVID-19 Vaccines , COVID-19 , Aged , Antibody Formation , Blood Donors , England/epidemiology , Health Personnel , Humans , RNA, Messenger , SARS-CoV-2 , Seroepidemiologic Studies , Vaccination
SELECTION OF CITATIONS
SEARCH DETAIL