The Mimivirus infects amoebas (where it was first discovered), and poses no threat to human beings. Its structure is that of a polygon covered with fibrils (hairs) that, when included in the measurement of the virus, can double its apparent size.he Mimivirus infects amoebas (where it was first discovered), and poses no threat to human beings. Its structure is that of a polygon covered with fibrils (hairs) that, when included in the measurement of the virus, can double its apparent size.