This study compares two treatments, IV BCV and IV CDV, for adenovirus (AdV) infection in patients who have had an allogeneic hematopoietic cell transplant (allo-HCT). Adenovirus is a virus that can cause infections, especially in people with weakened immune systems. The study will see how well each treatment works to clear the virus from the blood. Participants will be treated for up to 12 weeks or until the virus is no longer detectable. Even after treatment ends, participants will be followed for 24 weeks to monitor their health.

• Participation involves weekly visits and follow-ups for 24 weeks.
• The study will provide the assigned treatment, but no other form of compensation is mentioned.
• There are potential risks if allergic to the treatments or have certain medical conditions.