COVID 19 Special Collection
COVID-19 (SARS-CoV-2) Special Collection
Latest COVID-19 Articles
ASM is committed to broadly disseminating research relevant to public health emergencies. This collection highlights all COVID-19/SARS-CoV-2 research published across ASM Journals. All content is free to read and available for text and data mining via PubMed Central.
-
Research Article
A SARS-CoV-2 Label-Free Surrogate Virus Neutralization Test and a Longitudinal Study of Antibody Characteristics in COVID-19 Patients
Methods designed to measure SARS-CoV-2 humoral response include virus neutralization tests to determine antibody neutralization activity. For ease of use and universal applicability, surrogate virus neutralization tests (sVNTs) based on antibody-mediated blockage of molecular interactions have been proposed. A surrogate virus neutralization test was established on a label-free immunoassay platform (LF-sVNT). The LF-sVNT analyzes the binding ability of SARS-CoV-2 spike protein receptor-binding domain (RBD) to ACE2 after neutralizing RBD with antibodies in serum. The LF-sVNT neutralizing antibody titers (IC50) were determined from serum samples (n=246) from COVID-19 patients (n=113), as well as the IgG concentrations and the IgG avidity indices. Although there was variability in the kinetics of the IgG concentrations and neutralizing antibody titers between individuals, there was an initial rise, plateau and then in some cases a gradual decline at later timepoints after 40 days post-symptom onset. The IgG avidity indices, in the same cases, plateaued after an initial rise and did not show a decline. The LF-sVNT can be a valuable tool in research and clinical laboratories for the assessment of the presence of neutralizing antibodies to COVID-19. This study is the first to provide longitudinal neutralizing antibody titers beyond 200 days post-symptom onset. Despite the decline of IgG concentration and neutralizing antibody titer, IgG avidity index increases, reaches a plateau and then remains constant up to 8 months post-infection. The decline of antibody neutralization activity can be attributed to the reduction in antibody quantity rather than the deterioration of antibody quality, as measured by antibody avidity.
Accepted Manuscript Posted 7 April 2021, JCM
-
Research Article
Clinical evaluation of the Abbott Alinity SARS-CoV-2 spike-specific quantitative IgG and IgM assays among infected, recovered, and vaccinated groups
The COVID-19 pandemic continues to impose a significant burden on global health infrastructure. While identification and containment of new cases remains important, laboratories must now pivot and consider an assessment of SARS-CoV-2 immunity in the setting of the recent availability of multiple COVID-19 vaccines. Here we have utilized the latest Abbott Alinity semi-quantitative IgM and quantitative IgG spike protein (SP) serology assays (IgMSP and IgGSP) in combination with Abbott Alinity IgG nucleocapsid (NC) antibody test (IgGNC) to assess antibody responses in a cohort of 1236 unique participants comprised of naïve, SARS-CoV-2 infected, and vaccinated (including both naïve and recovered) individuals. The IgMSP and IgGSP assays were highly specific (100%) with no cross-reactivity to archived samples collected prior to the emergence of SARS-CoV-2, including those from individuals with seasonal coronavirus infections. Clinical sensitivity was 96% after 15 days for both IgMSP and IgGSP assays individually. When considered together, the sensitivity was 100%. A combination of NC- and SP-specific serologic assays clearly differentiated naïve, SARS-CoV-2-infected, and vaccine-related immune responses. Vaccination resulted in a significant increase in IgGSP and IgMSP values, with a major rise in IgGSP following the booster (second) dose in the naïve group. In contrast, SARS-CoV-2 recovered individuals had several fold higher IgGSP responses than naïve following the primary dose, with a comparatively dampened response following the booster. This work illustrates the strong clinical performance of these new serological assays and their utility in evaluating and distinguishing serological responses to infection and vaccination.
Accepted Manuscript Posted 7 April 2021, JCM
-
Research Article
Transmission and protection against re-infection in the ferret model with the SARS-CoV-2 USA-WA1/2020 reference isolate
The SARS-CoV-2 USA-WA1/2020 strain is a CDC reference strain used by multiple research laboratories. Here, we show the predominant mode of transmission of this isolate in ferrets is by direct contact. We further demonstrate ferrets are protected against re-infection for at least 56 days even when levels of neutralizing antibodies are low or undetectable. Last, we show that when ferrets were vaccinated by the intramuscular route to induce antibodies against SARS-CoV-2, ferrets remain susceptible to infection of the upper respiratory tract. Collectively, these studies suggest protection of the upper respiratory tract will require vaccine approaches that mimic natural infection.
Accepted Manuscript Posted 7 April 2021, JVI
-
Research Article
Development and validation of a multiplex microsphere immunoassay using dried blood spots for SARS-CoV-2 seroprevalence: application in first responders in Colorado, USA
Serological testing of large representative populations for antibodies to SARS-CoV-2 is needed to estimate seroprevalence, transmission dynamics, and the duration of antibody responses from natural infection and vaccination. In this study, a high-throughput SARS-CoV-2 multiplex microsphere immunoassay (MMIA) was developed for the receptor binding domain (RBD) and nucleocapsid (N) that was more sensitive than ELISA (98% vs 87%). The MMIA was then applied and validated in 264 first responders in Colorado using serum and dried blood spot (DBS) eluates, compared to ELISA and evaluated for neutralizing antibodies. Four percent (11/264) of first responders were seropositive in July-August 2020. Serum and DBS were highly correlated for anti-RBD and anti-N antibodies (R=0.83, p<0.0001 and R=0.87, p<0.0001, respectively) by MMIA. The MMIA accurately predicted SARS-CoV-2 neutralizing antibodies using DBS (R=0.76, p=0.037). On repeat antibody testing three months later, anti-RBD IgG decreased less rapidly than anti-N IgG measured by MMIA, with a median change in gMFI of 62% vs 79% (p<0.01), for anti-RBD and anti-N IgG respectively. This novel MMIA using DBS could be scalable for rapid and affordable SARS-CoV-2 serosurveillance in the U.S. and globally.
Accepted Manuscript Posted 1 April 2021, JCM
-
Genome Sequences
Genome Sequence of a SARS-CoV-2 Strain from a COVID-19 Clinical Sample from the Khagrachari District of Bangladesh
This study describes the genome sequence of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain detected in the nasopharyngeal swab sample of a coronavirus disease 2019 (COVID-19) patient from the southeastern Khagrachari District of Bangladesh.
1 April 2021, MRA
-
Genome Sequences
Coding-Complete Genome Sequence of a SARS-CoV-2 Strain Isolated in Gilgit, Pakistan
Here, we report the coding-complete genome sequence of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolate obtained from a nasopharyngeal swab from the first patient with COVID-19 in Gilgit, Pakistan.
1 April 2021, MRA