TABLE 1.

Representative plate maps of synergistic combination testing against LASV and JUNV pseudoviruses^a

^aVero cells were treated with the indicated concentrations of a single drug or a two- or three-drug combination of arbidol (Arb), amodiaquine (Amo), and aripiprazole (Ari) before infection with LASV (A) or JUNV (B) pseudovirus. Triple A refers to the combination of the three drugs. Data are expressed as a percentage of infected cells treated with the solvent control. At 24 h postinfection, luciferase activity was measured. The concentration of each drug alone providing ∼50% inhibition of infection is shaded blue. The concentration of each drug needed in the pairwise combinations to produce ∼50% inhibition of infection is shaded green. The concentration of each drug needed in the three-drug cocktail to yield ∼50% inhibition of infection is shaded yellow. The data show that the concentration of each drug required to inhibit LASV and JUNV pseudovirus infection shifts to the left (i.e., decreases) from a single drug to the two-drug and three-drug combinations. Summary fractional inhibitory concentration (FIC) scores for the drugs against LASV (C) and JUNV (D) are shown. Z-factors for each assay were 0.76 and 0.56, respectively, and the signal-to-noise ratios were 22,546 and 34,059 for LASV and JUNV, respectively. For LASV, the 1× concentrations of Arb, Amo, and Ari were 11, 8, and 12 μM, respectively. For JUNV, the 1× concentrations of Arb, Amo, and Ari were 8, 12, and 5 μM, respectively. Obs, observed; Exp, expected; n/a, not applicable.