ABSTRACT
The emergence of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) variants and "anatomical escape" characteristics threaten the effectiveness of current coronavirus disease (COVID-19) vaccines. There is an urgent need to understand the immunological mechanism of broad-spectrum respiratory tract protection to guide broader vaccines development. In this study, we investigated immune responses induced by an NS1-deleted influenza virus vectored intranasal COVID-19 vaccine (dNS1-RBD) which provides broad-spectrum protection against SARS-CoV-2 variants. Intranasal delivery of dNS1-RBD induced innate immunity, trained immunity and tissue-resident memory T cells covering the upper and lower respiratory tract. It restrained the inflammatory response by suppressing early phase viral load post SARS-CoV-2 challenge and attenuating pro-inflammatory cytokine (IL-6, IL-1B, and IFN-{gamma}) levels, thereby reducing excess immune-induced tissue injury compared with the control group. By inducing local cellular immunity and trained immunity, intranasal delivery of NS1-deleted influenza virus vectored vaccine represents a broad-spectrum COVID-19 vaccine strategy to reduce disease burden.
Subject(s)
COVID-19 , Coronavirus InfectionsABSTRACT
Antibody therapeutics for the treatment of COVID-19 has been highly successful while faces a challenge of the recent emergence of the Omicron variant which escapes the majority of existing SARS-CoV-2 neutralizing antibodies (nAbs). Here, we successfully generated a panel of SARS-CoV-2/SARS-CoV cross-neutralizing antibodies by sequential immunization of the two pseudoviruses. Of which, nAbs X01, X10 and X17 showed broadly neutralizing breadths against most variants of concern (VOCs) and X17 was further identified as a Class 5 nAb with undiminished neutralization against the Omicron variant. Cryo-EM structures of three-antibody in complex with the spike proteins of prototyped SARS-CoV-2, Delta, Omicron and SARS-CoV defined three non-overlapping conserved epitopes on the receptor-binding domain (RBD). The triple antibody cocktail exhibited enhanced resistance to viral escape and effective protection against the infection of Beta variant in hamsters. Our finding will aid the development of both antibody therapeutics and broad vaccines against SARS-CoV-2 and emerging variants.
Subject(s)
COVID-19ABSTRACT
Objective: To describe the temporal risk characteristics of coronavirus disease 2019 (COVID-19) in Gansu province.
ABSTRACT
COVID-19 patients develop hypolipidemia. However, it is unknown whether lipid levels have improved in recovered patients. In this study, a 3-6 month follow-up study was performed to examine serum levels of laboratory values in 107 discharged COVID-19 patients (mild = 59; severe/critical = 48; diagnoses on admission). 61 patients had a revisit chest CT scan. A Wilcoxon signed-rank test was used to analyze changes in laboratory values. LDL-c and HDL-c levels were significantly higher at follow-up than at admission in severe/critical cases (p < 0.05). LDL-c levels were significantly higher at follow-up than at admission in mild cases (p < 0.05). With adjustment of the factor of traditional Chinese medicine, LDL-c and HDL-c levels were significantly improved at follow-up than at admission in severe/critical cases (p < 0.05). Increases in HDL-c significantly correlated with increases in numbers of white blood cells (p<0.001) and decreases in levels of C-reactive protein (p < 0.05) during patients recovery. Residue lesions were observed in CT images in 69% (42 of 61) of follow-up patients. We concluded that improvements of LDL-c, HDL-c and incomplete absorption of lung lesions were observed at follow-up for recovered patients, indicating that a long-term recovery process could be required.