Self-prescribed Ivermectin use is associated with a lower rate of seroconversion in health care workers diagnosed with COVID, in a dose-dependent response Célia Pedroso; Sara Vaz; Eduardo Martins Netto; Daniele Souza; Felice Deminco; Rafaela Mayoral; Eliana Menezes; Ana Patricia Amancio da Cunha; Andres Moreira-Soto; Jan Felix Drexler; Carlos Brites;