Table 3.

Lung Virus Titers of MA-CA04–Infected Nude Mice Treated With the Indicated Neuraminidase and/or Polymerase Inhibitors^a

Group	Treatmentb	Virus Titer, Mean Log10 PFU ± SD/g
		Day 3	Day 7	Day 14	Day 21	Day 28
5-day treatment
1	Control	7.7 ± 0.3	7.1 ± 0.2	6.7 ± 0.3	NAc	NAc
2	OS	8.0 ± 1.0	6.9 ± 0.4	6.4 ± 1.0	NAc	NAc
3	LAO	7.9 ± 0.1	7.7 ± 0.5	6.8 ± 0.3	NAc	NAc
4	FA20	6.6 ± 1.4	6.9 ± 0.3	7.3 ± 0.3	4.8, 7.1, NAc	NAc
5	FA30	5.6 ± 0.4d	7.0 ± 0.2	7.1 ± 0.5	6.8 ± 0.1	NAc
6	OS + FA20	5.0 ± 0.4d,e	5.3 ± 1.5d	6.6 ± 0.3	6.7, NAc	NAc
7	LAO + FA20	6.9 ± 0.4e	4.2 ± 0.4d,e	7.2 ± 0.3	6.8 ± 0.8	NAc
8	OS + FA30	7.0 ± 0.3f	4.5 ± 0.2d,e	6.6 ± 0.3	6.6 ± 0.4	7.4, NA, NAc
9	LAO + FA30	7.1 ± 0.3f	6.2 ± 0.3e	7.0 ± 0.1	7.0 ± 0.4	7.3, 7.2, NAc
28-day treatment
10	Control	7.7 ± 0.3	7.4 ± 0.2	6.6, 7.2, NAc	NAc	NAc
11	OS	8.0 ± 1.0	6.7 ± 0.7	NAc	NAc	NAc
12	LAO	7.9 ± 0.1	7.6 ± 0.5	6.1, NA, NAc	NAc	NAc
13	FA20	6.6 ± 1.4	5.2 ± 1.0d	6.2 ± 0.2	6.2 ± 0.2	5.9 ± 0.8
14	FA30	5.6 ± 0.4d	6.1 ± 0.6	6.3 ± 0.1	5.8 ± 0.5g	6.3 ± 0.2
15	OS + FA20	5.0 ± 0.4d,e	5.4 ± 0.7	6.2 ± 0.4	6.6 ± 0.6	6.1 ± 0.9
16	LAO + FA20	6.9 ± 0.4	6.3 ± 0.3e,h	3.4 ± 0.4d,e,g	6.0 ± 0.4	6.1 ± 0.8
17	OS + FA30	7.0 ± 0.3f	6.2 ± 0.2h	4.7 ± 1.7d,e,g	5.8 ± 0.3	6.3 ± 0.1
18	LAO + FA30	7.1 ± 0.3f	6.3 ± 0.1e	5.7 ± 0.5g	6.6 ± 0.9	6.2 ± 0.2g

Abbreviations: FA20, low-dose favipiravir (20 mg/kg); FA30, high-dose favipiravir (30 mg/kg); LAO, laninamivir octanoate; OS, oseltamivir phosphate; NA, not applicable; PFU, plaque-forming units; SD, standard deviation.

^aMice were intranasally infected with 10⁴ PFU of virus.

Three mice from each group were euthanized on days 3, 7, 14, 21, and 28 postinfection.

^bTreatment details are shown in Table 2.

^cAnimal(s) succumbed to infection before the day of sampling.

^dVirus titers were significantly lower than in untreated animals;

^eVirus titers in animals treated with combination therapy were significantly lower than in those treated with monotherapy.

^fVirus titers after combination therapy were higher than those after FA30 monotherapy.

^gVirus titers in the 28-day treatment group were significantly lower than those in the respective 5-day treatment group.

^hVirus titers after the 28-day treatment were higher than after the 5-day treatment.