This Phase 2, open label, randomized study will investigate the virologic benefit, clinical efficacy, safety, and tolerability of amantadine and ribavirin with oseltamivir (TCAD) versus oseltamivir monotherapy for the treatment of all strains of influenza A in immunocompromised adult and pediatric subjects.

Inclusion Criteria:

• Confirmed influenza A by rapid antigen testing
• Immunocompromised as defined by recent solid organ or hematopoietic transplant, chronic graft vs. host disease, taking at least 2 immunosuppressants, undergoing chemotherapy, taking high dose chemotherapeutics, HIV positive
• Clinical diagnosis of influenza
• Onset of illness within 5 days
• Male and female subjects agree to contraception through 24 weeks after last dose

Exclusion Criteria:

• Received more than 1 dose of antiviral agents
• Critically ill
• Creatinine clearance less than 80 mg/mL
• Females who are pregnant and males whose female partners are pregnant
• Received live attenuated virus vaccine within 3 weeks