Parallel profiling of antigenicity alteration and immune escape of SARS-CoV-2 Omicron and other variants.

SARS-CoV-2 variants have evolved a variety of critical mutations, leading to antigenicity changes and immune escape. The recent emerging SARS-CoV-2 Omicron variant attracted global attention due to its significant resistance to current antibody therapies and vaccines. Here, we profiled the mutations of Omicron and other various circulating SARS-CoV-2 variants in parallel by computational interface analysis and in vitro experimental assays. We identified critical mutations that lead to antigenicity changes and diminished neutralization efficiency of a panel of 14 antibodies due to diverse molecular mechanisms influencing the antigen-antibody interaction. Our study identified that Omicron exhibited extraordinary potency in immune escape compared to the other variants of concern, and explores the application of computational interface analysis in SARS-CoV-2 mutation surveillance and demonstrates its potential for the early identification of concerning variants, providing preliminary guidance for neutralizing antibody therapy.

Rapid Development of SARS-CoV-2 Spike Protein Receptor-Binding Domain Self-Assembled Nanoparticle Vaccine Candidates.

The coronavirus disease pandemic of 2019 (COVID-19) caused by the novel SARS-CoV-2 coronavirus resulted in economic losses and threatened human health worldwide. The pandemic highlights an urgent need for a stable, easily produced, and effective vaccine. SARS-CoV-2 uses the spike protein receptor-binding domain (RBD) to bind its cognate receptor, angiotensin-converting enzyme 2 (ACE2), and initiate membrane fusion. Thus, the RBD is an ideal target for vaccine development. In this study, we designed three different RBD-conjugated nanoparticle vaccine candidates, namely, RBD-Ferritin (24-mer), RBD-mi3 (60-mer), and RBD-I53-50 (120-mer), via covalent conjugation using the SpyTag-SpyCatcher system. When mice were immunized with the RBD-conjugated nanoparticles (NPs) in conjunction with the AddaVax or Sigma Adjuvant System, the resulting antisera exhibited 8- to 120-fold greater neutralizing activity against both a pseudovirus and the authentic virus than those of mice immunized with monomeric RBD. Most importantly, sera from mice immunized with RBD-conjugated NPs more efficiently blocked the binding of RBD to ACE2 in vitro, further corroborating the promising immunization effect. Additionally, the vaccine has distinct advantages in terms of a relatively simple scale-up and flexible assembly. These results illustrate that the SARS-CoV-2 RBD-conjugated nanoparticles developed in this study are a competitive vaccine candidate and that the carrier nanoparticles could be adopted as a universal platform for a future vaccine development.

Clinical and radiologic features of the first cured Coronavirus disease 2019 (COVID-19) patient in Guangzhou City, China.

To determine changes in clinical and radiologic findings associated with Coronavirus disease 2019 (COVID-19) from diagnosis to recovery, we retrospectively reviewed the diagnosis and treatment records of the first patient cured of COVID-19 in Guangzhou. A 55-year-old woman from Wuhan was admitted to the hospital isolation ward with the chief complaint of "cough for 11 days and once fever 8 days ago" on January 22, 2020. COVID-19 was laboratory confirmed by reverse transcription polymerase chain reaction (RT-PCR) assay, and she received conventional antiviral therapy, such as moxifloxacin, traditional Chinese medicine, and arbidol. Repeat chest-computed tomography (CT) scans were performed on days 13 and 19 of her illness. The former showed radiologic findings, including ground-glass opacities (GGOs), which revealed viral pneumonia; the latter revealed that the previous lesions had been significantly absorbed. The lesions on CT scans were consistent with the changes in the course of disease. Some drugs, such as traditional Chinese medicine and arbidol, might play an important role in the recovery of COVID-19 patients. This study provides some new insights into the formulation of a timely and effective diagnostic and therapeutic strategy to cure patients with COVID-19.