Hyperimmune intravenous immunoglobulin containing high titers of pandemic H1N1 hemagglutinin and neuraminidase antibodies provides dose-dependent protection against lethal virus challenge in SCID mice

Table 1 Antibody titers and protection

Sample (dilution)	HI GMT			MN GMT			% survival
	In vitro^a	In vivo		In vitro^a	In vivo
		Day 3^b	Day 32^c		Day 3^b	Day 32^c
H-IVIG (undiluted)	1280	163	33	3420	349	34	100
H-IVIG (1:2)	640	143	26	1710	190	15	95
H-IVIG (1:4)	320	63	14	855	95	11	90
H-IVIG (1:8)	160	35	8	428	48	6	76
H-IVIG (1:16)	80	21	6	214	24	5	63
IVIG (undiluted)	70	6	7	60	5	5	50
Buffer control	n.a.	5	5	n.a.	5	5	40

^ain vitro titer of neat samples determined prior to i.p. injection; titers of diluted H-IVIG are calculated accordingly.
^bmouse serum titers 3 days after passive transfer; i.e. at the time of challenge.
^cmouse serum titers 32 days after passive transfer; i.e. 29 days after challenge.
HI, hemagglutination inhibition; MN, microneutralization; GMT, geometric mean titer; n.a., not applicable.
Note: IVIG was a pooled preparation from 5 different IVIG lots; 2 different lots of H-IVIG were used separately. Data shown are combined data from 2 independent experiments.

ISSN: 1743-422X