RESUMO
The prevalence of SARS-CoV-2 variants of concern (VOCs) is still escalating throughout the world. However, the level of neutralization of the inactivated viral vaccine recipients' sera and convalescent sera against all VOCs, including B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta), and B.1.1.529 (Omicron) remains to be lack of comparative analysis. Therefore, we constructed pseudoviruses of five VOCs using a lentiviral-based system and analyzed their viral infectivity and neutralization resistance to convalescent and BBIBP-CorV vaccinee serum at different times. Our results show that, compared with the wild-type strain (WT), five VOC pseudoviruses showed higher infection, of which B.1.617.2 and B.1.1.529 variant pseudoviruses exhibited higher infection rates than wild-type or other VOC strains, respectively. Sera from 10 vaccinated individuals at the 1, 3 and 5-month post second dose or from 10 convalescent at 14 and 200 days after discharge retained neutralizing activity against all strains but exhibited decreased neutralization activity significantly against the five VOC variant pseudoviruses over time compared to WT. Notably, 100% (30/30) of the vaccinee serum samples showed more than a 2.5-fold reduction in neutralizing activity against B.1.1.529, and 90% (18/20) of the convalescent serum samples showed more than 2.5-fold reduction in neutralization against B.1.1.529. These findings demonstrate the reduced protection against the VOCs in vaccinated and convalescent individuals over time, indicating that it is necessary to have a booster shot and develop new vaccines capable of eliciting broad neutralization antibodies.
RESUMO
The SARS-CoV-2 variants B.1.617.1 (Kappa) contain multiple mutations in the spike protein. However, the effect of B.1.617.1 lineage-related mutants on viral infectivity and inactivated-virus vaccine efficacy remains to be defined. We therefore constructed 12 B.1.617.1-related pseudoviruses and systematically studied the effects of mutations on virus infectivity and neutralization resistance to convalescent and inactivated virus vaccine sera. Our results show that the B.1.617.1 variant exhibited both higher infectivity and neutralization resistance in sera at 1 or 3 months after vaccination of 28 individuals and at 14 and 200 days after discharge of 15 convalescents. Notably, 89% of vaccines and 100% of the convalescent serum samples showed more than 2.5-fold reduction in neutralization against one single mutation: E484Q. Besides, we found a significant decrease in neutralizing activity in convalescent patients and BBIBP-CorV vaccines for B.1.1.529. These findings demonstrate that inactivated-virus vaccination or convalescent sera showed reduced, but still significant, neutralization against the B.1.617.1 variant.
RESUMO
The biology major has developed rapidly in recent years. Biology is a science that penetrates every aspect of human life and is one of the core majors in most agricultural colleges and universities. However, many teachers lack practical experience in the subject. To overcome this problem, in recent years, we have been trying to introduce new reforms into our teaching. This article provides some insight into the way that biology majors have been reformed, which will help educators in agricultural colleges and universities. At present, teachers implement the "Industrial Innovation and Entrepreneurship Talent Cultivation" (IIETC) model, but it is not clear whether this helps biology majors to master the course and improve their practical skills. In this study, the IIETC model is outlined, and the academic achievement and satisfaction of students taught under the IIETC model are assessed. A T-test is used to examine potential differences between IIETC and traditional teaching models. In-depth interviews and questionnaires were given to two groups of students who followed different teaching models as part of an exploratory study. The aim was to explore how effective IIETC is at helping biology majors master the course and improve students' wellbeing. Our results show that compared with traditional teaching methods, the IIETC model has a significant positive impact on the academic performance and happiness of biology students. Students trained under the IIETC model were more active and scored more highly in their final exams. They were more likely to feel that they had achieved success and happiness through the course (P = 0.03). The outcomes of this research reveal a novel teaching reform that improved students' enthusiasm for innovation and entrepreneurship during the ongoing COVID-19 pandemic. The effects are very encouraging and deserve further exploration and expansion in future work.