Fig. 5. A vaccine based on updated spike antigen S* prevents transmission of VOC Delta.
Effect of YF-S0* vaccination on viral transmission to non-vaccinated contact hamsters (n = 6 per group). Index hamsters were either sham vaccinated (n = 6) or vaccinated (n = 6) with a single dose of 104 PFU of YF-S0* and infected intranasally on day 21 with 105 TCID50 of VOC Delta. Two days after infection, index animals were paired and co-housed with each one naïve sentinel for 2 days. Index and sentinel animals were sacrificed each 4 days after infection or start of exposure, respectively. A Schematic of transmission experiment. B, C, Viral loads in hamster lungs 4 days after infection quantified by quantitative RT-qPCR (B) and virus titration (C). D Cumulative lung pathology scores from H&E-stained slides of lungs for signs of damage. Data for sentinels (purple circles; right) are each shown direct adjacent to their respective donor groups (left). Bar graphs denote median ± IQR. Dashed line represents the lower limit of quantification. Differences between groups were analyzed using nonparametric Kruskal–Wallis test uncorrected for ties.