TABLE 5.

Results of challenge study 2 for viremia in flavivirus-naive and DEN1mutF-immunized monkeys after challenge with 10⁶ PFU of wt DEN1WP

Monkey	Peak virus titer in sera (10−2)a
	RT-PCR	Plaque titration
642	2.2 (5) [1-5]	1.1 (4) [1-4]
CE40	1.1 (2) [1-2]	1.5 (3) [1-3]
CE8B	7.0 (3) [1-3]	2.5 (3) [1-3]
CE8C	7.2 (3) [1-3]	1.0 (3) [1-3]
KWDb	ND	ND
KGTc	ND	ND

^aPeak titer on any day of the study. For the RT-PCR assay, units are PFU equivalents per milliliter. For plaque titration, units are PFU per milliliter. Monkeys were infected on day 0 with 10⁶ PFU of DEN1WP, injected subcutaneously in the subscapular area. Virus in serial serum samples was detected and measured either by a quantitative, validated RT-PCR or by direct plaque formation on LLCMK2 cells. Values in parentheses are total number of days of viremia; values in brackets are days of the study on which viremia was observed. ND, not detected.

^bImmunized with DEN1mutF at 10⁵ PFU 17 months prior to challenge.

^cImmunized with DEN1mutF at 10³ PFU 17 months prior to challenge.