A therapeutic method of reducing or eliminating viral infections in vivo includes subjecting a virally infected patient to one of a variety of strong magnetic fields. A static magnetic field has a magnetic field intensity of at least about 5 nanoTesla sufficient to be effective to disrupt viral metabolism. An alternating magnetic field has a magnetic field intensity of at least 0.1 nanoTesla sufficient to be effective to disrupt viral metabolism. A method of disrupting viral metabolism includes subjecting an infected patient or a mixture of live host cells and virus to the alternating magnetic field. A virus disruption apparatus includes a magnetic field generator of static or alternating magnetic fields. The magnetic field generator is selected from a Magnetic Resonance Imaging device, at least one permanent magnet, at least one superconducting magnet, at least one solenoid, and any combination thereof.