Evaluation of humoral and cellular immunity of mice immunized with inactivated SARS-CoV-2 vaccine against Delta strain
10.13200/j.cnki.cjb.004475
- VernacularTitle:SARS-CoV-2灭活疫苗免疫小鼠后对Delta株病毒的体液及细胞免疫效果评价
- Author:
XU Kangwei
- Publication Type:Journal Article
- Keywords:
Inactivated vaccine;
SARS-CoV-2;
Humoral immunity;
Cellular immunity
- From:
Chinese Journal of Biologicals
2025;38(05):521-525
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the humoral and cellular immune effects of BALB/c mice immunized with prototype inac-tivated SARS-CoV-2 vaccine against Delta strain virus, and to provide a reference for evaluating the protective effect ofexisting vaccines against variant strains and developing safer and more effective vaccines.MethodsFemale BALB/c micewere intraperitoneally immunized with inactivated SARS-CoV-2 vaccine twice at an interval of 14 days, and mice immu-nized with PBS were used as control group, with 10 mice in each group. Serum samples were collected on the 7th, 14th,21st, 28th, 35th and 42nd days after the initial immunization. The binding antibody titers against the S and N proteins ofDelta strain virus were detected by indirect ELISA, and the neutralizing antibody titers against Delta strain virus weredetected by microneutralization test. On the 42nd day after the initial immunization, the spleen of mice was taken for Elispottest to evaluate the cellular immunity level.ResultsThe S protein-binding antibody was detected 7 days after the initialimmunization, and the antibody titer increased further after the boosting immunization, reaching a geometric mean titer(GMT) of 89 144 on the 21st day. However, the level of N protein-binding antibody was lower after the initial immunization,and increased rapidly after the boosting immunization, which was comparable to the level of S protein-binding antibody. Onthe 7th and 14th day after the initial immunization, the seroconversion numbers of neutralizing antibodies were 4/10 and 8/10, while all the antibodies showed seroconversion after the boosting immunization, with the GMT of neutralizing antibodiesof 391. On the 42nd day after the initial immunization, the average spots of IFNγ and IL-2 in the vaccine group were signifi-cantly more than those in the control group(t = 8. 094 and 13. 08, respectively, each P < 0. 000 1).ConclusionTwo timesimmunization with inactivated SARS-CoV-2 vaccine can effectively stimulate humoral and cellular immunity against Deltastrain virus in mice.
