Researchers discovered that a virus infecting the dangerous fungus Aspergillus fumigatus actually helps the fungus survive and cause worse infections in humans. By removing the virus from fungal strains, scientists found that the fungus became weaker and less able to cause disease in mice. Importantly, treating infected mice with an antiviral drug (ribavirin) reduced the viral load and helped the mice survive, suggesting a new approach to treating serious fungal infections.