Scientists have discovered three existing drugs - used for cancer, hepatitis C and for parasitic infections - that they say appear promising against the Zika virus.



The experiments were conducted only in lab-grown human cells in petri dishes, but the results were dramatic. Zika is so devastating that the damage it does has been thought to be irreversible. But the researchers said some of the compounds that the group tested not only allowed cells to live longer in the face of infection - but also in some cases fully recover from them.



The news, reported in Nature Medicine on Monday, is exciting but only a very preliminary step toward a treatment. The researchers will have to test the drugs in animal models to see if they can replicate the results, and if these tests are successful, they will have to start the long process of trying to test the drugs' effectiveness in humans.



Co-author Hongjun Song, director of the stem cell program at Johns Hopkins, said that the drugs "are very effective against Zika in the dish, but we don't know if they can work in humans in the same way."