Novel H5 clade 2.3.4.6 viruses with both α-2,3 and α-2,6 receptor binding properties may pose a pandemic threat

Table 2 Virus replication and seroconversion in guinea pigs

Virus stain	Replication in guinea pigs^a							Seroconversion of the guinea pigs in transmission studies
	Virus titers in organs(log₁₀EID₅₀/mL)						Seroconversion (positive/total)^d	Seroconversion: positive/total (HI titers)^e
	Nasal wash^b	Lung	trachea	spleen	kidney	brain	Seroconversion (positive/total)^d	Inoculated	Contact
DK/EC/1111/11	4.8 ± 0.3	3.5 ± 0.2	1.2 ± 0.2	- ^c	-	-	2/2	3/3(40,40,40)	0/3
GS/EC/1112/11	4.4 ± 0.7	3.2 ± 0.4	1.0 ± 0.1	-	-	-	2/2	3/3(80,40,40)	3/3(20,20,20)
Dkk1203	4.2 ± 1.6	2.8 ± 0.5	0.8 ± 0.1	-	-	-	2/2	3/3(80,80,40)	0/3
DkQ1	4.3 ± 1.3	2.7 ± 0.3	0.8 ± 0.2	-	-	-	2/2	3/3(80,40,40)	0/3
HD/05	-	1.0 ± 0.2	-	-	-	-	0/2
CA/04	5.4 ± 0.4	4.5 ± 0.3	2.8 ± 0.4	-	-	-	2/2	3/3(160,320,320)	3/3(80,160,160)

^aGroups of four guinea pigs were slightly anesthetized and intranasally inoculated with 10⁶EID₅₀ of test virus in a 300 μL volume, 150 μL per nostril. Two animals from each group were euthanized on day 3 pi and samples, including nasal wash, lung, trachea, spleen, kidney and brain, were collected for virus titration in eggs. The remaining two animals were observed for two weeks and sera were collected at the end of the observation period.
^bData shown are log₁₀EID₅₀/mL.
^cvirus was not detected in the undiluted sample.
^dSeroconversion was confirmed by hemagglutination inhibition (HI) assay.
^eSera were collected from guinea pigs on day 14 pi and treated overnight with Vibrio cholera receptor-destroying enzyme. Seroconversion was confirmed by hemagglutination inhibition (HI) assay.