Fig. 5: Dalbavancin shows significant anti-SARS-CoV-2 effects in rhesus macaque model.

a Schematic of rhesus macaque model of SARS-CoV-2 infection. Macaques were randomly assigned to either the saline group (n = 3) or dalbavancin group (n = 3, administrated by intravenous infusion over 0.5 h) and inoculated with SARS-CoV-2 (1 × 10⁷ TCID₅₀) via intratracheal (300 μL) and intranasal (200 μL) administration. At 7 dpi, animals from each group were euthanized and necropsied for virological and pathological assays. b Dalbavancin concentration analysis in serum of rhesus macaques infected with SARS-CoV-2. Dalbavancin was administered twice (two arrows, first 60 mg/kg, second 30 mg/kg) for 7 d. Dalbavancin showed a long half-life in serum. Means ± SD are shown. c Top, radiographs collected from each animal taken on 0 and 5 dpi. Areas of pulmonary infiltration are marked with a red circle. Middle, lungs from vehicle- or dalbavancin-treated monkeys. Dalbavancin-treated animals showed no visible pathological changes (red arrows). Bottom, histological analysis was performed on seven lung lobes from three animals per treatment group and representative images were chosen. Severe subpleural interstitial pneumonia and congestion were observed in three out of three vehicle-treated animals. Minimal (2/3) and moderate (1/3) subpleural interstitial pneumonia was observed in three dalbavancin-treated animals. Scale bars, 250 μm. d Left: Dalbavancin reduced viral loads in tissues collected from all seven lung lobes at 7 dpi from rhesus macaques infected with SARS-CoV-2. Right: Dalbavancin reduced virus titers in tissues collected from all seven lung lobes at 7 dpi from rhesus macaques. The seven lung lobe tissues (0.03 g) of one monkey were mixed and homogenized for virus titer test. Statistical significance was measured by two-tail t-test compared with control group.