Fig. 5

Protective immunogenicity of E2ZJ in piglets. Twenty-five piglets were randomly divided into 5 groups (E, F, G, H and L, n = 5). Groups E to G were respectively immunized with a single dose of E2ZJ at 5 μg, 15 μg or 30 μg. Group H was immunized with a single dose of 60 μg of Non-ZJ E2. Group L was injected with PBS as control. a Detection of CSFV-specific antibodies in pig sera with ELISA. Serum samples from pigs immunized with different antigens after days post vaccination were collected to detect the CSFV-specific antibodies using the IDEXX HerdChek® CSFV Antibody Test Kit. b, c Detection of CSFV neutralizing antibody in pig sera. Neutralization titer was determined against 100 TCID₅₀ of CSFV HZ08 strain (b) and Shimen strain (c). PBS: the group was injected with PBS only. d Rectal temperatures of the piglets after challenge with CSFV Shimen strain. Non-ZJ E2 was a CSFV E2 candidate vaccine expressed in HEK293 expression system other than baculovirus. Experiments were performed in triplicate and data are shown as mean ± SD. Statistical significance is indicated as (ns) (P > 0.05): *(P < 0.05); **(P < 0.01)