Antigenic mapping reveals sites of vulnerability on α-HCoV spike protein.

Understanding the antigenic signatures of all human coronaviruses (HCoVs) Spike (S) proteins is imperative for pan-HCoV epitopes identification and broadly effective vaccine development. To depict the currently elusive antigenic signatures of α-HCoVs S proteins, we isolated a panel of antibodies against the HCoV-229E S protein and characterized their epitopes and neutralizing potential. We found that the N-terminal domain of HCoV-229E S protein is antigenically dominant wherein an antigenic supersite is present and appears conserved in HCoV-NL63, which holds potential to serve as a pan-α-HCoVs epitope. In the receptor binding domain, a neutralizing epitope is captured in the end distal to the receptor binding site, reminiscent of the locations of the SARS-CoV-2 RBD cryptic epitopes. We also identified a neutralizing antibody that recognizes the connector domain, thus representing the first S2-directed neutralizing antibody against α-HCoVs. The unraveled HCoVs S proteins antigenic similarities and variances among genera highlight the challenges faced by pan-HCoV vaccine design while supporting the feasibility of broadly effective vaccine development against a subset of HCoVs.

Epidemiological and clinical characteristics of SARS-CoV-2 Omicron variant

The COVID-19 pandemic continues to rage worldwide and the SARS-CoV-2 Omicron variant has now replaced the Delta variant as the leading epidemic strain.Omicron, as one of the SARS-COV-2 variants, incorporates the most critical mutations of the Alpha and Delta variants, and is characterized by having multiple mutation sites, high viral load, stronger infectivity and immune escape, which significantly reduced the protective effect of the vaccine.However, compared with the previous SARS-CoV-2 strains, the Omicron variant is less likely to infect lung tissue, it usually causes mild clinical symptom with reduced hospitalization rate, severe disease rate and fatality rate.Three doses of allogeneic vaccine can offer better tolerance and immunogenicity, and improve the protective effect of the vaccines.The application of small-molecule antiviral drugs and neutralizing antibodies can significantly reduce the hospitalization rate and mortality rate.In this paper, the epidemiological and characteristics of the Omicron variant were reviewed in order to provide reference for clinical diagnosis and treatment of the disease.