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The Omicron variant of SARS-CoV-2 has rapidly become the dominant infective strain and the focus efforts against the ongoing COVID-19 pandemic. Here we report an extensive set of structures of the Omicron spike trimer by its own or in complex with ACE2 and an anti-Omicron antibody. These structures reveal that most Omicron mutations are located on the surface of the spike protein, which confer stronger ACE2 binding by nearly 10 folds but become inactive epitopes resistant to many therapeutic antibodies. Importantly, both RBD and the closed conformation of the Omicron spike trimer are thermodynamically unstable, with the melting temperature of the Omicron RBD decreased by as much as 7{degrees}C, making the spiker trimer prone to random open conformations. An unusual RBD-RBD interaction in the ACE2-spike complex unique to Omicron is observed to support the open conformation and ACE2 binding, serving the basis for the higher infectivity of Omicron. A broad-spectrum therapeutic antibody JMB2002, which has completed Phase 1 clinical trial, is found to interact with the same two RBDs to inhibit ACE2 binding, in a mode that is distinguished from all previous antibodies, thus providing the structural basis for the potent inhibition of Omicron by this antibody. Together with biochemical data, our structures provide crucial insights into higher infectivity, antibody evasion and inhibition of Omicron.
RESUMO
Objective@#To investigate the status and influencing factors of health literacy of middle school students in Yinchuan City, to provide reference for health literacy improvement of middle school students in this region.@*Methods@#Using stratified cluster sampling method, 2 003 middle school students from three districts of Yinchuan were investigated to complete the questionnaire survey.The survey included basic characteristics, health literacy and screen time status.@*Results@#The total score of Chinese Adolescent Interactive Health Literacy Questionnaire was(101.3±17.5). The proportion of high, medium and low level of health literacy were 25.0%, 51.2% and 23.9% respectively;the proportion of long screen time exposure among middle school students was 52.5%. The health literacy level of junior middle school students, middle school students with father or mother education level of high school or above and appropriate screen time were higher than those of the corresponding group（χ 2=49.90，14.59，16.53，46.73，P<0.01）. Logistic regression analysis showed that education group, grade, father s or mother s education level and long screen time exposure were associated with middle school students health literacy level(P<0.05).@*Conclusion@#The health literacy level of middle school students in Yinchuan City needs to be further improved and targeted health education should be carried out from school, family and society.
