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Open accessJournal ArticleDOI: 10.1371/JOURNAL.PONE.0247797

Longitudinal SARS-CoV-2 antibody study using the Easy Check COVID-19 IgM/IgG™ lateral flow assay.

04 Mar 2021-PLOS ONE (Public Library of Science (PLoS))-Vol. 16, Iss: 3
Abstract: Since the initial identification of the novel coronavirus SARS-CoV-2 in December of 2019, researchers have raced to understand its pathogenesis and begun devising vaccine and treatment strategies. An accurate understanding of the body's temporal immune response against SARS-CoV-2 is paramount to successful vaccine development and disease progression monitoring. To provide insight into the antibody response against SARS-CoV-2, plasma samples from 181 PCR-confirmed COVID-19 patients collected at various timepoints post-symptom onset (PSO) were tested for the presence of anti-SARS-CoV-2 IgM and IgG antibodies via lateral flow. Additionally, 21 donors were tracked over time to elucidate patient-specific immune responses. We found sustained levels of anti-SARS-CoV-2 antibodies past 130 days PSO, with 99% positivity observed at 31-60 days PSO. By 61-90 days PSO, the percentage of IgM-/IgG+ results were nearly equal to that of IgM+/IgG+ results, demonstrating a shift in the immune response with a decrease in IgM antibody levels. Results from this study not only provide evidence that the antibody response to COVID-19 can persist for over 4 months, but also demonstrates the ability of Easy Check™ to monitor seroconversion and antibody response of patients. Easy Check was sufficiently sensitive to detect antibodies in patient samples as early as 1-4 days PSO with 86% positivity observed at 5-7 days PSO. Further studies are required to determine the longevity and efficacy of anti-SARS-CoV-2 antibodies, and whether they are protective against re-infection.

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Topics: Seroconversion (56%), Antibody (51%), Serology (50%)

6 results found

Open accessPosted ContentDOI: 10.1101/2021.08.22.21262294
26 Aug 2021-medRxiv
Abstract: Summary Background Even after adjusting for the expected lower severity due to the younger age of the population, relatively low SARS-CoV-2 incidence and mortality rates have been reported throughout Africa. For investigating whether this is truly the case, we conducted a survey to estimate the COVID-19 related mortality and cumulative incidence of SARS-CoV-2 infections in Omdurman the most populated city of the tripartite metropolis Khartoum in Sudan. Methods A retrospective, cross–sectional, mortality and seroprevalence survey was conducted in Omdurman, Sudan, from March 1, until April 10 2021. A two–stage cluster sampling method was used to investigate the death rate for the pre–pandemic (January 1, 2019–February 29, 2020) and pandemic (March 1, 2020 – day of the survey) period using questionnaires. The seroprevalence survey was performed in a subset of households and all consenting members were tested with a rapid serological test (SD–Biosensor) and a subgroup additionally with ELISA (EUROIMMUN). Fisher’s exact test was used to assess differences between the pre–and pandemic periods and a random effect and Bayesian latent class model to adjust for test performance. Findings Data from 27315 people (3716 households) for the entire recall period showed a 67% (95% CI 32–110) increase in death rate between the pre–pandemic (0.12 deaths/10000 people/day [95% CI 0.10–0.14]) and pandemic (0.20 [0.16–0.23]) periods. Notably, a 74% (30–133) increase in death was observed among people aged ≥50 years. The adjusted seroprevalence of SARS-CoV-2 was 54.6% (95% CI 51.4–57.8). The seroprevalence was significantly associated with age, increasing up to 80.7% (71.7–89.7) for the oldest age group (≥50 years). Interpretation Our results showed a significant elevated mortality for the pandemic period with a considerable excess mortality in Omdurman, Sudan. The overall high seroprevalence indicated a different age pattern compared to other countries, with a significant increase by age. Funding Medecins Sans Frontieres

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Topics: Mortality rate (56%), Seroprevalence (56%), Population (52%) ... read more

1 Citations

Open accessPosted ContentDOI: 10.1101/2021.08.19.456951
Alexander J. Stewart1, Emma Sinclair1, Ilaria Serangeli2, Nora Kasar1  +12 moreInstitutions (5)
19 Aug 2021-bioRxiv
Abstract: Immunoglobulin gene heterogeneity reflects the diversity and focus of the humoral immune response towards different infections, enabling inference of B cell development processes. Detailed compositional and lineage analysis of long read IGH repertoire sequencing, combining examples of pandemic, epidemic and endemic viral infections with control and vaccination samples, demonstrates general responses including increased use of IGHV4-39 in both EBOV and COVID-19 infection cohorts. We also show unique characteristics absent in RSV infection or yellow fever vaccine samples: EBOV survivors show unprecedented high levels of class switching events while COVID-19 repertoires from acute disease appear underdeveloped. Despite the high levels of clonal expansion in COVID-19 IgG1 repertoires there is a striking lack of evidence of germinal centre mutation and selection. Given the differences in COVID-19 morbidity and mortality with age, it is also pertinent that we find significant differences in repertoire characteristics between young and old patients. Our data supports the hypothesis that a primary viral challenge can result in a strong but immature humoral response where failures in selection of the repertoire risks off-target effects.

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Topics: Immunoglobulin gene (54%), Repertoire (51%), Yellow fever vaccine (51%) ... read more

Open accessJournal ArticleDOI: 10.1016/J.IDCR.2021.E01291
01 Jan 2021-IDCases
Abstract: Coronavirus infection disease 2019 (COVID-19) has been linked to the development of various autoimmune disorders. Lofgren syndrome, consisting of bilateral pulmonary hilar lymphadenopathy, erythema nodosum and polyarthritis, is a rare autoimmune disease that represents an acute form of sarcoidosis. We present the case of Lofgren syndrome developing in close temporal association with COVID-19. Clinical presentation consisted of fever, bilateral lung lymphadenopathy, arthralgias and erythema nodosum. Hilar lymph node biopsy revealed pathology consistent with sarcoidosis. Three weeks prior to presentation, the patient experienced respiratory symptoms. Serological examination at the time of presentation revealed positive IgM and IgG antibodies against SARS-CoV-2 nucleocapsid protein. Most symptoms resolved following a course of oral prednisone. This case report suggests a possible link between COVID-19 and the development of sarcoidosis, however, further studies are needed to conclude this association.

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Topics: Sarcoidosis (65%), Erythema nodosum (60%), Löfgren syndrome (54%) ... read more

Open accessJournal ArticleDOI: 10.3390/VACCINES9060587
Jodi F. Hedges1, Macy A Thompson1, Deann T. Snyder1, Amanda Robison1  +2 moreInstitutions (1)
02 Jun 2021-Vaccine
Abstract: Information concerning the development of neutralizing antibodies and their duration will be critical to establishing herd immunity for COVID-19. We sought to evaluate SARS-CoV-2 spike protein receptor-binding domain (RBD)-specific antibodies, their duration, and capacity for SARS-CoV-2 neutralization in volunteers while the pandemic spread within our community starting in March 2020. Those participants with the highest starting titers had the longest-lasting response, up to 12 months post-diagnosis. SARS-CoV-2 neutralization capacity was correlated with anti-RBD antibody levels. The majority of our participants with confirmed COVID-19 diagnosis had very mild or asymptomatic infections. We also detected low and largely non-neutralizing anti-RBD IgG titers in a few participants with no known COVID-19 diagnosis. Finally, we found that antibody responses induced by vaccination were significantly higher than those induced by natural infection. Thus, our study suggests that vaccination is still critical even for those naturally infected or diagnosed with COVID-19.

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Topics: Vaccination (53%), Herd immunity (52%)

Open accessJournal ArticleDOI: 10.1016/J.TRAC.2021.116460
Abstract: Viruses are responsible for multiple infections in humans that impose huge health burdens on individuals and populations worldwide. Therefore, numerous diagnostic methods and strategies have been developed for prevention, management, and decreasing the burden of viral diseases, each having its advantages and limitations. Viral infections are commonly detected using serological and nucleic acid-based methods. However, these conventional and clinical approaches have some limitations that can be resolved by implementing other detector devices. Therefore, the search for sensitive, selective, portable, and costless approaches as efficient alternative clinical methods for point of care testing (POCT) analysis has gained much attention in recent years. POCT is one of the ultimate goals in virus detection, and thus, the tests need to be rapid, specific, sensitive, accessible, and user-friendly. In this review, after a brief overview of viruses and their characteristics, the conventional viral detection methods, the clinical approaches, and their advantages and shortcomings are firstly explained. Then, LFA systems working principles, benefits, classification are discussed. Furthermore, the studies regarding designing and employing LFAs in diagnosing different types of viruses, especially SARS-CoV-2 as a main concern worldwide and innovations in the LFAs' approaches and designs, are comprehensively discussed here. Furthermore, several strategies addressed in some studies for overcoming LFA limitations like low sensitivity are reviewed. Numerous techniques are adopted to increase sensitivity and perform quantitative detection. Employing several visualization methods, using different labeling reporters, integrating LFAs with other detection methods to benefit from both LFA and the integrated detection device advantages, and designing unique membranes to increase reagent reactivity, are some of the approaches that are highlighted.

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38 results found

Open accessJournal ArticleDOI: 10.1038/S41586-020-2012-7
Peng Zhou1, Xing-Lou Yang1, Xian Guang Wang2, Ben Hu1  +25 moreInstitutions (3)
03 Feb 2020-Nature
Abstract: Since the outbreak of severe acute respiratory syndrome (SARS) 18 years ago, a large number of SARS-related coronaviruses (SARSr-CoVs) have been discovered in their natural reservoir host, bats1–4. Previous studies have shown that some bat SARSr-CoVs have the potential to infect humans5–7. Here we report the identification and characterization of a new coronavirus (2019-nCoV), which caused an epidemic of acute respiratory syndrome in humans in Wuhan, China. The epidemic, which started on 12 December 2019, had caused 2,794 laboratory-confirmed infections including 80 deaths by 26 January 2020. Full-length genome sequences were obtained from five patients at an early stage of the outbreak. The sequences are almost identical and share 79.6% sequence identity to SARS-CoV. Furthermore, we show that 2019-nCoV is 96% identical at the whole-genome level to a bat coronavirus. Pairwise protein sequence analysis of seven conserved non-structural proteins domains show that this virus belongs to the species of SARSr-CoV. In addition, 2019-nCoV virus isolated from the bronchoalveolar lavage fluid of a critically ill patient could be neutralized by sera from several patients. Notably, we confirmed that 2019-nCoV uses the same cell entry receptor—angiotensin converting enzyme II (ACE2)—as SARS-CoV. Characterization of full-length genome sequences from patients infected with a new coronavirus (2019-nCoV) shows that the sequences are nearly identical and indicates that the virus is related to a bat coronavirus.

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Topics: Coronavirus (67%), Betacoronavirus (54%), Deltacoronavirus (51%) ... read more

12,056 Citations

Open accessJournal ArticleDOI: 10.1038/S41586-020-2008-3
Fan Wu1, Su Zhao2, Bin Yu3, Yan-Mei Chen1  +17 moreInstitutions (4)
03 Feb 2020-Nature
Abstract: Emerging infectious diseases, such as severe acute respiratory syndrome (SARS) and Zika virus disease, present a major threat to public health1–3. Despite intense research efforts, how, when and where new diseases appear are still a source of considerable uncertainty. A severe respiratory disease was recently reported in Wuhan, Hubei province, China. As of 25 January 2020, at least 1,975 cases had been reported since the first patient was hospitalized on 12 December 2019. Epidemiological investigations have suggested that the outbreak was associated with a seafood market in Wuhan. Here we study a single patient who was a worker at the market and who was admitted to the Central Hospital of Wuhan on 26 December 2019 while experiencing a severe respiratory syndrome that included fever, dizziness and a cough. Metagenomic RNA sequencing4 of a sample of bronchoalveolar lavage fluid from the patient identified a new RNA virus strain from the family Coronaviridae, which is designated here ‘WH-Human 1’ coronavirus (and has also been referred to as ‘2019-nCoV’). Phylogenetic analysis of the complete viral genome (29,903 nucleotides) revealed that the virus was most closely related (89.1% nucleotide similarity) to a group of SARS-like coronaviruses (genus Betacoronavirus, subgenus Sarbecovirus) that had previously been found in bats in China5. This outbreak highlights the ongoing ability of viral spill-over from animals to cause severe disease in humans. Phylogenetic and metagenomic analyses of the complete viral genome of a new coronavirus from the family Coronaviridae reveal that the virus is closely related to a group of SARS-like coronaviruses found in bats in China.

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Topics: Coronavirus (62%), Betacoronavirus (59%), Zika virus disease (54%) ... read more

6,266 Citations

Open accessJournal ArticleDOI: 10.1016/J.CELL.2020.05.015
25 Jun 2020-Cell
Abstract: Understanding adaptive immunity to SARS-CoV-2 is important for vaccine development, interpreting coronavirus disease 2019 (COVID-19) pathogenesis, and calibration of pandemic control measures. Using HLA class I and II predicted peptide "megapools," circulating SARS-CoV-2-specific CD8+ and CD4+ T cells were identified in ∼70% and 100% of COVID-19 convalescent patients, respectively. CD4+ T cell responses to spike, the main target of most vaccine efforts, were robust and correlated with the magnitude of the anti-SARS-CoV-2 IgG and IgA titers. The M, spike, and N proteins each accounted for 11%-27% of the total CD4+ response, with additional responses commonly targeting nsp3, nsp4, ORF3a, and ORF8, among others. For CD8+ T cells, spike and M were recognized, with at least eight SARS-CoV-2 ORFs targeted. Importantly, we detected SARS-CoV-2-reactive CD4+ T cells in ∼40%-60% of unexposed individuals, suggesting cross-reactive T cell recognition between circulating "common cold" coronaviruses and SARS-CoV-2.

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Topics: Coronavirus (54%)

1,935 Citations

Open accessJournal ArticleDOI: 10.1038/S41591-020-0897-1
Quanxin Long1, Bai Zhong Liu2, Hai Jun Deng1, Gui Cheng Wu3  +47 moreInstitutions (4)
29 Apr 2020-Nature Medicine
Abstract: We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.

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Topics: Seroconversion (64%)

1,864 Citations

Open accessJournal ArticleDOI: 10.1038/S41591-020-0965-6
Quanxin Long1, Xiaojun Tang2, Qiu Lin Shi2, Qin Li3  +15 moreInstitutions (3)
18 Jun 2020-Nature Medicine
Abstract: The clinical features and immune responses of asymptomatic individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have not been well described We studied 37 asymptomatic individuals in the Wanzhou District who were diagnosed with RT-PCR-confirmed SARS-CoV-2 infections but without any relevant clinical symptoms in the preceding 14 d and during hospitalization Asymptomatic individuals were admitted to the government-designated Wanzhou People's Hospital for centralized isolation in accordance with policy1 The median duration of viral shedding in the asymptomatic group was 19 d (interquartile range (IQR), 15-26 d) The asymptomatic group had a significantly longer duration of viral shedding than the symptomatic group (log-rank P = 0028) The virus-specific IgG levels in the asymptomatic group (median S/CO, 34; IQR, 16-107) were significantly lower (P = 0005) relative to the symptomatic group (median S/CO, 205; IQR, 58-382) in the acute phase Of asymptomatic individuals, 933% (28/30) and 811% (30/37) had reduction in IgG and neutralizing antibody levels, respectively, during the early convalescent phase, as compared to 968% (30/31) and 622% (23/37) of symptomatic patients Forty percent of asymptomatic individuals became seronegative and 129% of the symptomatic group became negative for IgG in the early convalescent phase In addition, asymptomatic individuals exhibited lower levels of 18 pro- and anti-inflammatory cytokines These data suggest that asymptomatic individuals had a weaker immune response to SARS-CoV-2 infection The reduction in IgG and neutralizing antibody levels in the early convalescent phase might have implications for immunity strategy and serological surveys

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Topics: Asymptomatic (64%), Interquartile range (51%)

1,854 Citations