Background: With the goal of understanding how the virus behaves is necessary a development of animal models and adapted viral strains that are able to infect immunocompetent animals and can cause symptoms in animals similar to human symptoms. Methodology/Principal Findings: Our methodology was basically a pass strain of dengue type 1 or serotype 1 (DENV -1) several times in brain of newborn mice and inoculation of this virus in immunocompetent mice C57Black/6, (WT) and for comparison as well as in immunodeficient animals IFN -/- (susceptible to virus) as iNOS-/- (resistant to virus) and...