Sequential immunization with inactivated SARS-CoV-2 vaccines induces humoral immune responses against Wuhan-Hu1 and Omicron variants
10.3760/cma.j.cn/112866-20230106-00002
- VernacularTitle:新冠灭活疫苗序贯免疫对Wuhan-Hu1和Omicron变异株的体液免疫反应
- Author:
Xiuli SHEN
1
;
Yanling HAO
;
Shuhui WANG
;
Ying LIU
;
Li REN
;
Dan LI
;
Meiling ZHU
;
Jing LI
;
Wenqi TANG
;
Bin LI
;
Yiming SHAO
Author Information
1. 中国疾病预防控制中心性病艾滋病预防控制中心 传染病预防控制国家重点实验室，北京 102206
- Keywords:
Inactivated Omicron vaccine;
Omicron variants;
BA.4/5;
BF.7;
Neutralizing antibodies;
Humoral immune response
- From:
Chinese Journal of Experimental and Clinical Virology
2023;37(2):121-127
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the ability of sequential immunization regimen inducing neutralizing antibodies against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) Wuhan-Hu1 and Omicron variants in mice.Methods:Groups of 6-8-week-old BALB/c mice were primed with two doses of Wuhan-Hu-1 inactivated vaccine, and then boosted with Omicron or Wuhan-Hu-1 inactivated vaccine, respectively. Binding antibodies were tested by enzyme linked immunosorbent assay; and neutralizing antibodies against Wuhan-Hu1 and Omicron variants were analyzed by vesicular stomatitis virus pseudovirus assay system; SARS-CoV-2 specific cellular immune responses were quantified by enzyme-linked immunosorbent spot assay.Results:IgG antibodies against Wuhan-Hu1, Delta and Omicron RBD were enhanced after the second dose of Wuhan-Hu1 inactivated vaccine. Compared with Wuhan-Hu1 inactivated vaccine, the group boosted with Omicron inactivated vaccine improved Wu-RBD and Omic-RBD specific IgG antibodies 1.41 and 1.26 times, and serum neutralizing antibodies against BA.1, BA.2, BA.4/5 and BF.7 were elevated 4.5, 3.4, 12.1 and 6.5 folds, respectively, by sequential immunization. After booster immunization with inactivated Wuhan-Hu1 or Omicron vaccines, Wu-RBD IgA titer was significantly higher than that of one dose inactivated Wuhan-Hu1 vaccine ( P=0.005 7, P=0.006 1). Conclusions:Neutralizing antibodies against Omicron variants were enhanced by sequential immunization with Omicron inactivated vaccine. Specific IgA was significantly enhanced after the third dose of inactivated vaccine.
