A cohort of cancer patients with no reported cases of SARS-CoV-2 infection: the possible preventive role of Methylene Blue

We report the case of a cohort of 2500 French patients treated among others with methylene blue for cancer care. During the COVID-19 epidemics none of them developed influenza-like illness. Albeit this lack of infection might be by chance alone, it is possible that methylene blue might have a preventive effect for COVID-19 infection. This is in line with the antiviral activity of Chloroquine, a Methylene blue derivative. Both Chloroquine and Methylene blue have strong antiviral and anti- inflammatory properties probably linked to the change in intracellular pH and redox state.