Fig. 4: Vaccines’ protection from a challenge with the Omicron BA.1 VOC. | npj Vaccines

Fig. 4: Vaccines’ protection from a challenge with the Omicron BA.1 VOC.

From: Cross-protection and cross-neutralization capacity of ancestral and VOC-matched SARS-CoV-2 adenoviral vector-based vaccines

Fig. 4

BALB/c mice were immunized with CoroVaxG.3-O.FR (a and c) or with a prime/boost scheme (b and c). Sera from vaccinated mice was used in an ELISA to assess IgG levels against Wu-1 Spike (a and b) and Omicron BA.1 Spike (c). Transgenic mice vaccinated at day −42 with a priming dose and at day −28 with a booster dose were challenged with Omicron at day 0. At day +3 postchallenge, 6-7 mice of each group were euthanized and all the organs were removed (d). Samples of nasal washes (e and f) and lungs (g and h) were used to assess viral load by qPCR of gE (e and g) and sgE (f and h). The rest of the mice were followed to assess weight changes after the challenge (i). Samples of lungs at day 3 after the challenge were analyzed to obtain the pathology score (j), for expression of N protein (k) and CD3 + T cells (l). The presence of syncytial cells in the lungs of unvaccinated (m) and vaccinated mice (n) is shown (arrowheads). Samples of brains at day 3 postchallenge were analyzed to obtain the pathology score (o), for expression of N protein (p) and CD3 + T cells (q). Number of mice analyzed: unvaccinated mice at day 3 (n = 7), while for vaccinated mice we analyzed n = 6 for the boost with CoroVaxG.3 and n = 7 for the other two groups of boosted mice; at day 14 for all groups (n = 6); 3 naïve mice were assessed for viral load and histological studies. Differences between experimental groups of animals for gE and sgE were analyzed by ANOVA with Bonferroni a posteriori and Kruskal-Wallis test with Dunn´s multiple comparisons a posteriori, respectively. Two-way ANOVA with Dunnett a posteriori was used for analyzing changes in body weight. Data is presented as mean standard error of mean (SEM). p < 0.05, **p < 0.01 and ***p < 0.001. The box plots in ac, el and oq show the median, 25th and 75th percentiles, and the whiskers show the range.

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