ABSTRACT
The research, development and application of corona virus disease 2019 (COVID-19) vaccine play an important role against the global pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. There are 11 candidate vaccines that have been issued for emergency use list (EUL) by WHO, which have been shown effective protection with safety against infection, severe diseases and death in clinical trials and real world. They have become powerful weapons for human beings to prevent infection and transmission of SARS-CoV-2. In this paper, the efficacy and safety of COVID-19 vaccines were briefly reviewed. Copyright © 2022, Chinese Journal of New Drugs Co. Ltd. All right reserved.
ABSTRACT
Objective To prepare antiserum against S protein of SARS-CoV-2 and preliminarily develop a method for determination of antigen content in inactivated SARS-CoV-2 vaccine. Methods Goats and rabbits were immunized with recombinant S protein of SARS-CoV-2, and the obtained antisera were determined for titer by indirect ELISA and neutralization assay and for specificity by Western blot, then purified by protein G resin affinity chro-matography. A sandwich ELISA for determination of antigen content of inactivated SARS-CoV-2 vaccine was developed by using purified goat antibody as capture antibody and purified rabbit antibody as detection antibody. Results The titer of antiserum of goats after immunization for 4 times reached 220 000 by ELISA and 1 536 by neutralization assay, while that of rabbits after immunization for 3 times reached 220 000 by ELISA and 4 096 by neutralization assay. Both goat and rabbit antibodies showed specific binding to the S protein of SARS-CoV-2. A double antibody sandwich ELISA method for determination of antigen content was successfully developed by using the purified antibodies, which showed a good linearity with a R2 value of more than 0. 99. Conclusion High titer goat and rabbit antisera against S protein of SARS-CoV-2 were prepared successfully, and double antibody sandwich ELISA method for determination of antigen content of inactivated SARS-CoV-2 vaccine was preliminarily developed. © 2021 Changchun Institute of Biological Products. All rights reserved.
ABSTRACT
Transmission of infectious respiratory diseases through airborne dispersion of viruses poses a great risk to public health. In several major diseases, one of the main modes of transmission is through respiratory droplets. Virus laden respiratory droplets and aerosols can be generated during coughing, sneezing and speaking. These droplets and aerosols can remain suspended in air and be transported by airflow posing a risk of infection in individuals who might come in contact with them. With this background, in this work, we present a numerical framework for simulation of dispersion of respiratory sputum droplets using implicit large-eddy simulations. A combination of discrete Lagrangian droplet model and fully compressible Navier-Stokes flow solver is employed in this study. The method is applied to analyze cases such as droplet dispersion during speech and cough under different environmental settings. Furthermore, the performance of the numerical framework is evaluated through strong and weak scaling analysis. © 2021 ACM.
ABSTRACT
Objective To prepare high titer neutralizing antiserum against SARS-CoV-2. Methods SPF rabbits were immunized with RBD protein of SARS-CoV-2, expressed in 293 cells, as an immunogen. The prepared antiserum was determined for titer by ELISA and microneutralization test, and distributed to several manufacturers for development of inactivated SARS-CoV-2 vaccine for determination of titer. Results After 3 times of immunization, the antiserum titer reached more than 1 600 000, while the neutralizing titer was 8 192. The geometric mean titer (GMT) determined by microneutralization test in five manufacturers was 6. 950. Conclusion High titer neutralizing antiserum against SARS-CoV-2 was successfully prepared and distributed to several manufacturers of inactivated SARS-CoV-2 vaccine candidate for virus identification and adventitious virus agent test, which broke through the technical bottleneck restricting the rapid development of SARS-CoV-2 vaccine. © 2020 Changchun Institute of Biological Products. All rights reserved.