As the coronavirus SARS-CoV-2 spreads globally, we keep tracking the latest scientific findings and knowledge on the coronavirus and disease (COVID-19). We update this article regularly by searching contents of relevant journals and websites.
Research advance| June 06
The paper was published at Cell and researchers reported the pilot-scale production of an inactivated SARS-CoV-2 vaccine candidate (BBIBP-CorV) that induces high levels of neutralizing antibodies titers in mice, rats, guinea pigs, rabbits and nonhuman primates (cynomolgus monkeys and rhesus macaques) to provide protection against SARS-CoV-2. Two-dose immunizations using 2 μg/dose of BBIBP-CorV provided highly efficient protection against SARS-CoV-2 intratracheal challenge in rhesus macaques, without detectable antibody-dependent enhancement of infection. In addition, BBIBP-CorV exhibits efficient productivity and good genetic stability for vaccine manufacture. These results support the further evaluation of BBIBP-CorV in a clinical trial. Learn More.
In this study, researchers reported the isolation and characterization of 206 RBD-specific monoclonal antibodies derived from single B cells of eight SARS-CoV-2 infected individuals. They identified antibodies with potent anti-SARS-CoV-2 neutralization activity that correlates with their competitive capacity with ACE2 for RBD binding. Surprisingly, neither the anti-SARS-CoV-2 antibodies nor the infected plasma cross-reacted with SARS-CoV or MERS-CoV RBDs, although substantial plasma cross-reactivity to their trimeric Spike proteins was found. Crystal structure analysis of RBD-bound antibody revealed steric hindrance that inhibits viral engagement with ACE2 and thereby blocks viral entry. These findings suggest that anti-RBD antibodies are viral species-specific inhibitors. The antibodies identified here may be candidates for the development of SARS-CoV-2 clinical interventions. Learn More
Research advance| May 26
In this paper published at Nature, researchers reported the isolation of 2 specific human monoclonal antibodies (MAbs) from a convalescent COVID-19 patient. CA1 and CB6 demonstrated potent SARS-CoV-2-specific neutralization activity in vitro against SARS-CoV-2. In addition, CB6 inhibited SARS-CoV-2 infection in rhesus monkeys at both prophylactic and treatment settings. Further structural studies revealed that CB6 recognizes an epitope that overlaps with angiotensin converting enzyme 2 (ACE2)-binding sites in SARS-CoV-2 receptor binding domain (RBD), thereby interfering with the virus/receptor interactions by both steric hindrance and direct interface-residue competition. Their results suggest CB6 deserves further clinical translation. Learn More.
Research advance| May 26
In this study, researchers generated a mouse model expressing human ACE2 (hACE2) using CRISPR/Cas9 knock-in technology. Compared with wild-type C57BL/6 mice, both young and aged hACE2 mice sustained high viral loads in lung, trachea and brain upon intranasal infection. Although fatalities were not observed, interstitial pneumonia and elevated cytokines were seen in SARS-CoV-2 infected- aged hACE2 mice. Interestingly, intragastric inoculation of SARS-CoV-2 was evidenced to cause productive infection and lead to pulmonary pathological changes in hACE2 mice. Overall, this animal model described here provides a useful tool for studying SARS-CoV-2 transmission and pathogenesis, and evaluating COVID-19 vaccines and therapeutics. Learn More.
Research advance| May 22
Prof Wei Chen’s team did a dose-escalation, single-centre, open-label, non-randomised, phase 1 trial of an Ad5 vectored COVID-19 vaccine in Wuhan, China. They found that the Ad5 vectored COVID-19 vaccine is tolerable and immunogenic at 28 days post-vaccination. Humoral responses against SARS-CoV-2 peaked at day 28 post-vaccination in healthy adults, and rapid specific T-cell responses were noted from day 14 post-vaccination. Our findings suggest that the Ad5 vectored COVID-19 vaccine warrants further investigation. Learn More.