Table 4.

Lethality of N. nivea venom and its neutralization by antivenoms used in Africa.

i.v. LD50 a (µg/g)	s.c. LD50 a (µg/g)	Antivenom	Antivenom Protein Concentration (mg/mL)	Challenge Dose	ED50 b (µL)	ER50 c (mg/mL)	Potency d (mg/mL)	Normalized Potency e (n-P)	Reference
1.11 (0.73–1.69)	2.42 (2.10–2.79)	VAPAV	130.68 ± 2.83 #	2.5	74.61	0.86 (0.61–1.20)	0.51	3.90	Current study
0.84 (0.57–1.04)	-	SAIMR	118.4	2.0	17.81	1.70 (1.49–1.94)	0.94	7.94	[16]
0.45 (0.43–0.47)	-	Antivipmyn-Africa	32	3.0	57.11	0.47 (0.47–0.48)	0.31	9.69	[17]
3.55 (95% CI: NA)	-	VACSERA	NA	NA	Not effective				[18]

Abbreviation: i.v., intravenous; s.c., subcutaneous; LD₅₀, median lethal dose; ED₅₀, median effective dose; ER₅₀, median effective ratio; NA, not available. ^a LD₅₀, the dose of venom (μg) per gram of mouse body weight at which 50% of mice died. ^b ED₅₀, the dose of antivenom (μL) at which 50% of mice survived. ^c ER₅₀, the ratio of venom (mg) to the volume of antivenom (ml) at which 50% of mice survived. ^d Potency, the amount of venom (mg) completely neutralized per ml antivenom (mg/mL). ^e Normalized potency, the amount of venom (mg) completely neutralized per g antivenom protein (mg/g). ^# Protein concentration of VAPAV is as previously reported for the same sample [19].