Disposition of patients
This open-label, multicenter, parallel-group, randomized controlled trial was conducted between September 1, 2020 and March 31, 2022 at four institutes in Osaka, Japan. The last entry was on September 22, 2021, when the delta variant of SARS-CoV-2 was prevalent in Japan. Twenty-three hospitalized patients who provided informed consent and were screened were randomized into three groups: a control group (n = 7), demeclocycline 150 mg daily group (n = 8), and demeclocycline 300 mg daily group (n = 8) (Fig. Flow diagram.