TABLE 1.

Viremia in monkey sera after primary and secondary DENV-2 infections as estimated by viral isolation and RT-PCR

Monkey	Strain used for primary inoculation	Passage historya	Viremia on the indicated day afterb:
			Primary infection										Secondary infection
			1	2	3	4	5	6	7	8	9	10	1	2	3	4	5	6	7	8	9	10
I	DENV-2 A15	4 MB, 2 C6/36			×, +	×, +	×, +	×	×											×
II	DENV-2 A15	4 MB, 2 C6/36		×	×	×, +	×, +	×													×
III	DENV-2 A15	4 MB, 2 C6/36	×	×	×, +	×, +	×, +	×
IV	DENV-2 Jamaica	3 M, 5 C6/36			×, +	×, +	×, +												×
V	DENV-2 I348600	? M, 5 C6/36			×, +	×, +	×, +	×	×											×

^aMB, mouse brain; M, mosquitoes; C6/36, C6/36-HT cells.

^b×, positive by RT-PCR; +, positive by viral isolation. Days of inoculation and challenge were considered day zero.