Low-dose mucosal SIV challenge has same kinetics as high-dose challenge.

2004 MAY 5 - (NewsRx.com & NewsRx.net) -- Repeated low-dose mucosal simian immunodeficiency virus SIVmac239 challenge results in the same viral and immunological kinetics as high-dose challenge.

According to published research from the United States, "Simian immunodeficiency virus (SIV) challenge of rhesus macaques provides a relevant model for the assessment of human immunodeficiency virus (HIV) vaccine strategies. To ensure that all macaques become infected, the vaccinees and controls are exposed to large doses of pathogenic SIV. These nonphysiological high-dose challenges may adversely affect vaccine evaluation by overwhelming potentially efficacious vaccine responses.

"To determine whether a more physiologically relevant low-dose challenge can initiate infection and cause disease in Indian rhesus macaques, we used a repeated low-dose challenge strategy designed to reduce the viral inoculum to more physiologically relevant doses," said Adrian B. McDermott and colleagues at the University of Wisconsin-Madison. "In an attempt to more closely mimic challenge with HIV, we administered repeated mucosal challenges with 30, 300, and 3,000 50% tissue culture infective doses (TCID[subscript]50) of pathogenic SIVmac239 to six animals in three groups.

"Infection was assessed by sensitive quantitative reverse transcription-PCR and was achieved following a mean of 8, 5.5, and 1 challenges in the 30, 300, and 3,000 TCID[subscript]50 groups, respectively," reported the researchers. "Mortality, humoral immune ...