CLDN5 and COVID-19: The authors declare that the expression of the von Willebrand factor increases in the decidua endothelium and in the chorionic villi of the placenta derived from women with COVID-19, being higher in severe cases; Claudin-5 and VE-cadherin expression decreased in the decidua and chorionic villi of the placenta of women with severe COVID-19 but not in those with mild disease.