Table 2.

Protection against a lethal ECTV challenge when a combination of Dryvax (DVX) and BCV are given as pre- and post-exposure prophylaxis to A-strain mice.^a Mice were administered Dryvax (2.5 × 10⁵ PFU/mouse) and co-administered an initial dose of BCV (or vehicle) via oral gavage at 10 mg/kg on T = −4, 0, 2, or 4 days followed by 2.5 mg/kg doses of BCV given on Days 2, 4, 6, 8, 10, 12, and 14 following the initial dose. At T = 0 days, mice were challenged via the IN route with 40 PFU (20× LD₅₀) of ECTV.

Group	# of mice	Vaccine		Antiviral		Treatment (T=, day)	ECTV	Day of Death (rtc)b	MTD ± SEMb	Mortality (%)
		DVXb	Veh	BCVb	Veh
1	10		+		+	−4	+	7,7,8,8,8,9,9,10,10,10	8.6 ± 0.4	100
2	10	+			+	−4	+	42	42	10⁎
3	10	+		+		−4	+			0⁎
4	10		+	+		−4	+	26,27	26.5 ± 0.5⁎	20⁎
5	10	+			+	0	+	8,8,8,8,8,8,8,8,9,13	8.6 ± 0.5	100
6	10	+		+		0	+			0⁎
7	10		+	+		0	+	53,15	34 ± 19⁎	20⁎
8	10	+			+	2	+	7,7,8,8,8,8,8,8,9,9,	8 ± 0.2	100
9	10	+		+		2	+	9,10,10,10,10	9.8 ± 0.2⁎	50⁎
10	10		+	+		2	+			0⁎
11	10	+			+	4	+	7,7,8,8,8,8,8,8,8,9	7.9 ± 0.2	100
12	10	+		+		4	+	10,10,12,12,12,14,15,29	14.3 ± 2.2⁎	80
13	10		+	+		4	+	9,11,11,11,12,12,13,20	12.4 ± 1.2⁎	80
14	10	+			+	0	−			0⁎
15	10	+		+		0	−			0⁎
16	10		+	+		0	−			0⁎
17	10		+		+	0	−			0⁎
18	5	N/A	N/A	N/A	N/A	N/A	N/A			0⁎

^⁎P < 0.05 compared to controls.

^aProtocol is described in the legend of Fig. 4.

^bDVX, Dryvax; BCV, Brincidofovir; MTD, mean time to death; SEM, standard error of mean; rtc, relative to challenge.