Fig. 3
Detection of the virulence and protective effects of the RH-Δompdc strain in mice. a Attenuated virulence of the RH-Δompdc strain in mice was observed. Mice (n = 8) infected with 100 RH-WT tachyzoites (i.p.) all died within 10 days, and mice (n = 8) infected with 106 or 2 × 106 RH-Δompdc tachyzoites (i.p.) all survived. b RH-Δompdc immunization provided protection against RH-WT infection. After being immunized with PBS or 1 × 106 or 2 × 106 RH-Δompdc (i.p.) for 30 days, the mice were challenged with 100 RH-WT tachyzoites (i.p.). The mice in the PBS group (n = 7) all died within 9 days after the challenge, while the mice in the 1 × 106 and 2 × 106 RH-Δompdc immunization groups (n = 7) showed survival rates of 71.4 and 100%, respectively. Results are representative of three independent experiments. Data were analyzed by survival curves: log-rank (Mantel–Cox) test. Asterisks indicate significant difference at ***P < 0.001. Abbreviations: i.p., intraperitoneal injection; PBS, phosphate-buffered saline