Live attenuated vaccination protects aged chimeric ACE2 mice from severe SARS-CoV-2 pathogenicity in vivo
Fig 9
LAVNsp16 immunized aged animals are protected from homologous or heterologous SARS-CoV-2 challenge.
Aged chACE2 mice were immunized with 7x104 PFU of LAVNsp16. At 21 days postinfection, immunized and naïve mice were challenged with 7x104 PFU virus of either the B.1 (WT, homologous) or the Delta (heterologous) variant. Mice were sacrificed at four days postchallenge, or when predefined welfare endpoints were reached (clinical score ≥ 20) at day 3 (♦). Weight measurements, normalized to the initial bodyweight of wt virus (A) or Delta virus (B) infected animals are shown as mean + /- s.d. Survival rates of animals challenged with wt (C) or Delta (D) virus are shown. Viral loads in bronchoalveolar lavage (BAL) (E) and lung tissue (F) were determined by RT-qPCR and plotted as mean + /- s.d. overlayed by individual data points. Statistical analysis was performed by two-way ANOVA followed by Bonferroni’s correction for multiple comparison.