A patient begins an antiviral that reduces their daily productive viral replication by 70% each day (i.e., viral output each day is 30% of the previous day). If the baseline plasma viral load is 1,000,000 copies/mL, what is the expected viral load after 3 days of therapy?

• A. 27,000 copies/mL (1,000,000 × 0.30³ = 1,000,000 × 0.027).
• B. 2,700 copies/mL assuming a compounded 90% reduction per day as antiviral potency increases over time.
• C. 300,000 copies/mL because a 70% reduction over three days is 1,000,000 × 0.30.
• D. 70,000 copies/mL because each day the virus is reduced by 70% and then you subtract a cumulative fixed 30,000 copies per day from the baseline.

Answer: (A)