Effect of GS-441524 in combination with the 3C-like protease inhibitor GC376 on the treatment of naturally transmitted feline infectious peritonitis.

Objectives: The main objectives of this study were to investigate the efficacy of the nucleotide analog GS-441524 in combination with the 3C-like protease inhibitor GC376 for the treatment of naturally aquired feline infectious peritonitis (FIP) and to test whether their combination shortens the dosing period and improves the cure rate. Methods: In total, 46 FIP-affected cats were enrolled in this experiment, including 36 with wet FIP (29 with abdominal effusion, six with thoracic effusion, and one with thoracic+abdominal effusion), and 10 with dry FIP. The cats were aged from 3 to 96 months. Thoracic+abdominal effusion, lymph-node puncture fluid and perirenal puncture fluid was collected from the affected cats for qPCR testing, and all 46 cats were positive for feline coronavirus (FCoV). The cats divided into different dose groups, all treated for 4 weeks: group 1 (GS-441524, 5 mg/kg.sc.q.24 h; GC376, 20 mg/kg.sc.q.12 h), group 2 (GS-441524, 2.5 mg/kg.sc.q.24 h; GC376, 20 mg/kg.sc.q.12 h), group 3 (GS-441524, 2.5 mg/kg.sc.q.24 h; GC376, 10 mg/kg.sc.q.12 h), and group 4 (GS-441524, 5 mg/kg.sc.q.24 h; GC376, 10 mg/kg.sc.q.12 h). Results: After the 4-week combination treatment, 45 of the 46 (97.8%) cats survived, and 43 of those became clinically normal. Two cats required longer (7 to 12 weeks) treatment to achieve full recovery. As of writing (10 months after completion of the trial), all 45 cats were alive and no relapse was observed. Conclusions and relevance: GS-441524 combined with GC376 can be safely and effectively used to treat FIP and reduces the treatment period to 4 weeks, with an excellent cure rate.

Serological survey of SARS-CoV-2 for experimental, domestic, companion and wild animals excludes intermediate hosts of 35 different species of animals.

The pandemic SARS-CoV-2 has been reported in 123 countries with more than 5,000 patients died from it. However, the original and intermediate hosts of the virus remain unknown. In this study, 1,914 serum samples from 35 animal species were used for detection of SARS-CoV-2-specific antibodies using double-antigen sandwich ELISA after validating its specificity and sensitivity. The results showed that no SARS-CoV-2-specific antibodies were detected in above samples which excluded the possibility of 35 animal species as intermediate host for SARS-CoV-2. More importantly, companion animals including pet dogs (including one dog the SARS-CoV-2 patient kept and two dogs which had close contact with it) and cats, street dogs and cats also showed serological negative to SARS-CoV-2, which relieved the public concerns for the pets as SARS-CoV-2 carriers.