Fig. 5: Candidate vaccine protects G129 mice against organ infection and injury.

a Body weight measured up to 28 dpi, expressed as the mean percentage of initial weight ± standard deviation; N = 5 mice/group. b Testis weight at day 28 post-infection. c Testis image. d Viral titer in various organs of mice was measured by qRT-PCR (relative expression). e Viremia after challenge measurements by qRT-PCR (relative expression) were performed on days 2, 5, and 8 post-infection. f–i Brains in distinct regions (midbrain and cerebral cortex) from ZIKV-infected was processed for histological staining with hematoxylin and eosin (HE). f Representative uninfected animals with no abnormalities observed. g White arrows indicate necrotic areas in sham-immunized animals. h and i Vaccinated groups show no abnormalities. j–m Histological analysis of the testis from ZIKV-infected G129 mice. j Abnormalities were not observed from uninfected G129 mice. k Disrupted seminiferous tubules with disorganized cells (large black arrows) and various degenerating germinal epithelial cells (black arrows) were observed inside the seminiferous tubules of ZIKV-infected testes. Additionally, intratesticular varicoceles/congestion (white arrow) and lymphocyte infiltration (small black arrows) were present in the interstitial areas of sham ZIKV-infected G129 testes. l and m Normal seminiferous tubules with different steps of germinal epithelial cells (arrow) in order and normal intratesticular capillary (arrow) in immunization G129 mice testis. The 4 μm-thick sections were stained with HE and images were captured with Slide Digitizer-3D Histech scanner. The number of animals per group was: only EDIII-20 µg, n = 8 (females), Sham (PBS) n = 4 (2 females, 2 males), EDIII-QβVLP-20 µg, n = 15 (11 females, 4 males), and EDIII-QβVLP-50 µg, n = 15 (11 females, 4 males). Data were analyzed by Kruskal–Wallis, and post-hoc by Dunn in b, d, e. *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001.