.  Experimental Ct and computed VR values using the 2-ΔΔCT approximation are shown in supplementary material Table S2. Given this range of estimates, for the next step we approximated the in vivo plausible range of SARS-CoV-2 replication inhibition per cycle due to TDF between 90% (namely high inhibition) and 60% (namely moderate inhibition) approximating the inhibition resulting from a plausible range of 12-36h for the viral cycle [21] .