Figure 2. The protective effects against CVB3-induced acute myocarditis by co-immunization of chitosan-pAIM2 and chitosan-pVP1. Seven days after 3LD₅₀ CVB3 challenge at week 2 after the last immunization, the protect effects were evaluated in mice. (A) Body weight loss. (B) Representative M-mode echocardiograms. (C) Left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) from echocardiographic data. (D) Serum CK, CK-MB activity. (E) The representative heart section was shown for each group (magnification: 100 ×). (F) Myocardial histopathological scores. (G) Viral titers in the heart tissues were measured by plaque assays. Data are from one representative experiment of 3 performed and presented as the mean ± SD (n = 10). *P < 0.05, **P < 0.01, ***P < 0.001. (H) The survival rate of mice was observed until day 28 following a lethal dose of CVB3 (5LD₅₀) infection. Data are from one representative experiment of 3 performed and presented as the mean ± SD (n = 12). ***P < 0.001.