Since January 2020, Elsevier has established a COVID-19 resource center on its public news and information website, Elsevier Connect, providing free English and Mandarin information about the novel coronavirus. Elsevier has granted permission to make all COVID-19-related research available in PubMed Central and other public repositories, allowing unrestricted reuse and analysis with acknowledgment of the original source. The article also discusses the repurposing of chloroquine and hydroxychloroquine as potential antiviral treatments for COVID-19. Following in vitro studies showing chloroquine's activity against SARS-CoV-2, clinical trials in China reported positive results, indicating that chloroquine could reduce the severity and duration of symptoms in patients with COVID-19 pneumonia. The authors highlight the rationality of using chloroquine for intracellular infections, citing its effectiveness in treating malaria and other intracellular bacterial infections. They also emphasize the potential of hydroxychloroquine, which shares similar mechanisms of action with chloroquine, for treating SARS-CoV-2. The optimal dosage for SARS-CoV-2 will need further assessment, but the authors suggest a loading dose followed by a maintenance dose.Since January 2020, Elsevier has established a COVID-19 resource center on its public news and information website, Elsevier Connect, providing free English and Mandarin information about the novel coronavirus. Elsevier has granted permission to make all COVID-19-related research available in PubMed Central and other public repositories, allowing unrestricted reuse and analysis with acknowledgment of the original source. The article also discusses the repurposing of chloroquine and hydroxychloroquine as potential antiviral treatments for COVID-19. Following in vitro studies showing chloroquine's activity against SARS-CoV-2, clinical trials in China reported positive results, indicating that chloroquine could reduce the severity and duration of symptoms in patients with COVID-19 pneumonia. The authors highlight the rationality of using chloroquine for intracellular infections, citing its effectiveness in treating malaria and other intracellular bacterial infections. They also emphasize the potential of hydroxychloroquine, which shares similar mechanisms of action with chloroquine, for treating SARS-CoV-2. The optimal dosage for SARS-CoV-2 will need further assessment, but the authors suggest a loading dose followed by a maintenance dose.