Immunology of SARS-CoV-2 infection and vaccination.

Comprehensive elucidation of humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination is critical for understanding coronavirus disease 2019 (COVID-19) pathogenesis in general and developing antibody-based diagnostic and therapeutic strategies specifically. Following the emergence of SARS-CoV-2, significant scientific research has been conducted worldwide using omics, sequencing and immunologic approaches. These studies have been critical to the successful development of vaccines. Here, the current understanding of SARS-CoV-2 immunogenic epitopes, humoral immunity to SARS-CoV-2 structural proteins and non-structural proteins, SARS-CoV-2-specific antibodies, and T-cell responses in convalescents and vaccinated individuals are reviewed. Additionally, we explore the integrated analysis of proteomic and metabolomic data to examine mechanisms of organ injury and identify potential biomarkers. Insight into the immunologic diagnosis of COVID-19 and improvements of laboratory methods are highlighted.

Performance verification of five commercial RT-qPCR diagnostic kits for SARS-CoV-2.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has caused a global pandemic beginning in 2020, can be detected by reverse-transcription polymerase chain reaction (RT-PCR). However, owing to the urgent need for a large number of detection kits, the time spent researching and developing these kits has been shortened during the pandemic, and the kits that are being used commercially have not undergone full and independent evaluation. To ensure the accuracy of SARS-CoV-2 test results, performance verification of commercial Real-Time quantitative PCR (RT-qPCR) kits is required. METHODS: The performance of five commercial RT-qPCR diagnostic kits for SARS-CoV-2 used in China was evaluated using a coronavirus disease 2019 (COVID-19) RNA liquid performance verification reference product-manufactured by Guangzhou Bondson (BDS) Biotechnology Co., Ltd.,Guangzhou, China-that uses droplet digital RT-PCR technology combined with fluorescence quantitative PCR. The five kits of Novel Coronavirus 2019-nCoV nucleic acid detection kit (RT-qPCR method) evaluated were Da An (Da An Gene Co., Ltd. of Sun Yat-sen University), Liferiver (Shanghai ZJ Bio-Tech Co., Ltd.), Kinghawk (Beijing Kinghawk Pharmaceutical Co., Ltd.), eDiagnosis (Wuhan Easy Diagnosis Biomedicine Co., Ltd.), and Maccura (Maccura Biotechnology Co., Ltd.). Performance verification criteria included the coincidence rate, limit of detection (LoD), cross-reactivity, precision, and anti-interference. Finally, through the BDS performance verification reference product kit, clinical samples are used to verify its clinical diagnostic efficacy. RESULTS: The coincidence rate was 100% for all kits except for Kinghawk, which was 95%. The LoD for Da An, eDiagnosis and Maccura was 250copies/mL, and it was 1000 copies/ml for Liferiver. Kinghawk was not able to detect its advertised LoD of 500 copies/ml. The cross-reactivity test results were all negative. Moreover, all kits had a coefficient of variation less than 5%; however, Liferiver showed the best precision. Da An, Liferiver, and eDiagnosis showed higher sensitivity to the nucleocapsid (N) gene than they did to the open reading frame (ORF) 1ab genes. Anti-interference results for all five kits were positive. The results of clinical diagnostic efficacy were that the specificity of the four kits was 1.000 (0.877-1.000), the sensitivity of Da An was 1.000 (0.850-1.000), Liferiver was 0.964 (0.798-0.998), Maccura was 0.893 (0.706-0.972), and eDiagnosis was 0.857 (0.664-0.953). CONCLUSIONS: All commercial RT-qPCR diagnostic kits for SARS-CoV-2 passed the BDS performance verification, except for Kinghawk (batch No:20200608113) which failed to detect the LoD of 500 copies/mL. Da An and Liferiver have excellent clinical diagnostic specificity and sensitivity. This study can provide guidance for the selection or optimization of RT-qPCR diagnostic test kits for SARS-CoV-2.

Progress in understanding COVID-19: insights from the omics approach.

Sequencing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome is a crucial task for controlling the ongoing coronavirus disease (COVID-19) pandemic. However, elucidating the pathological mechanisms of SARS-CoV-2 in humans has been challenging. A comprehensive analysis of the molecular characteristics of SARS-CoV-2 and molecular changes in COVID-19 patients may have practical significance in developing assays for the detection of SARS-CoV-2 and formulating clinical treatment strategies against COVID-19. The omics approach for studying biochemical mechanisms can be used to elucidate the molecular characteristics and pathophysiology of SARS-CoV-2. The omics-scale research on COVID-19 has been carried out rapidly, bringing hope for developing a robust diagnostic assay, discovering reliable biomarkers to assess disease progression, and developing therapeutic drugs and vaccines. In this review, we summarize, from an omics perspective, the strategies for the detection of SARS-CoV-2 antigens and antibodies against the virus, the metabolomic and proteomic changes in COVID-19 patients, and the progress of research on anti-SARS-CoV-2 drugs with their potential clinical applications.

Serological detection of 2019-nCoV respond to the epidemic: A useful complement to nucleic acid testing.

Corona Virus Disease 2019 (COVID-19) has spread rapidly to more than 215 countries, with over 11.91 million reported cases and more than 540,000 deaths. Rapid diagnosis remains a bottleneck for containing the epidemic. We used an automated chemiluminescent immunoassay to detect serum IgM and IgG antibodies to the 2019-nCoV in 742 subjects, so as to observe the dynamic process of antibody production in COVID-19 disease and seroepidemiology in different populations. Patients with COVID-19 were reactive (positive) for specific antibodies within 3-15 days after onset of symptoms. Specific IgM and IgG levels increased with the progression of the disease. The areas under the receiver operating characteristic curves for IgM and IgG were 0.984 and 1.000, respectively. This antibody detection assay had good sensitivity and specificity. The understanding of the dynamic serological changes of COVID-19 patients and the seroepidemiological situation of the population will be helpful to further control the epidemic of COVID-19.