Humoral immune responses to different doses of bivalent norovirus vaccine in mice / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To investigate the humoral immune response to GⅠ.1/GⅡ.4 norovirus (NoV) virus-like particle (VLP) vaccine of different doses in mice.Methods:The GⅠ.1/GⅡ.4 norovirus vaccine was diluted into four different concentrations, containing 50, 25, 8.3 and 2.8 μg/dose antigens, respectively. Aluminum hydroxide adjuvant was used in the control group. Ten 7-week-old BALB/c mice in each group were immunized intraperitoneally with 0.5 ml vaccine or adjuvant on 0 d and 21 d. Blood samples were collected on 35 d and the histoblood group antigen (HBGA) blocking titers of GⅠ.1 and GⅡ.4 antibodies in serum were detected. The differences in antibody levels between the groups were analyzed by SPSS23.0 software.Results:GⅠ.1 and GⅡ.4 HBGA blocking antibodies in 50, 25 and 8.3 μg/dose groups became positive on 35 d after the first dose vaccination. The geometric mean titers (GMT) of GⅠ.1 and GⅡ.4 HBGA blocking antibodies were 488 (95%CI 249-955) and 489 (95%CI 302-790) in 50 μg/dose group, 278 (95%CI 106-728) and 738 (95%CI 299-1 820) in 25 μg/dose group, 300 (95%CI 158-570) and 486 (95%CI 222-1 068) in 8.3 μg/dose group, respectively. The positive rates of GⅠ.1 and GⅡ.4 blocking antibodies in 2.8 μg/dose group were 40% and 70% and the GMT were 23 (95%CI 10-51) and 85 (95%CI 24-304), respectively. The GⅠ.1 and GⅡ.4 blocking antibodies in the control group were negative. Statistically significant differences in antibody levels were found between 50, 25, 8.3 μg/dose groups and the control group ( P<0.05), as well as in GⅠ.1 blocking antibodies between 50, 25, 8.3 μg/dose groups and 2.8 μg/dose group ( P<0.05). GⅡ.4 antibody level in 25 μg/dose group was statistically different from that in 2.8 μg/dose group ( P<0.05). Conclusions:GⅠ.1/GⅡ.4 norovirus VLP vaccine at (50-8.3) μg/dose could induce humoral immune response in mice.