Rapid preparation and application of high titer neutralizing antiserum against SARS-CoV-2

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.