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Table 1 Immune responses and viremia in SIV/ML29-infected monkeys and controls

From: An attenuated Lassa vaccine in SIV-infected rhesus macaques does not persist or cause arenavirus disease but does elicit Lassa virus-specific immunity

Animal ID Cell-mediated immunity (IFNγ response) 1 week after vaccinationb Antibody responsec Plasma Viremiad Time of euthanasia after ML29e SIV viral load at set pointf
SIV/ML-1 sca ++++ ++++ 80 pfu/ml Week 8 (M) 105-106
SIV/ML-2 sc ++ ++++ ---- >20 wks (S) 103-104
SIV/ML-3 sc ++ +++ 1000 pfu/ml Week 4 (R) 107-108
SIV/ML-4 sc ++ ++++ ---- >20 wks (M) 105-106
SIV/ML-5 sc +++ +++ ---- >20 wks (S) 104-105
SIV/ML-6 ig +++++ ---- ---- Week 14 (M) 105-106
SIV/ML-7 ig ---- ---- ---- Week 19 (M) 105
SIV/ML-8 ig +++ ---- 20 pfu/ml >20 wks (M) 105-106
SIV/ARM-1 sc ++ ++ ---- Week 16 (R) 107
SIV/ARM-2 sc ++ ++++ ---- >20 wks (S) 104
SIV/ARM-3 sc +++ +++ ---- Week 9 (R) 106-107
ML-1 sc +++ ++++ ---- >20 wks ----
ML-2 sc +++ +++ ---- >20 wks ----
ML-3 sc ++ +++ + >20 wks ----
ML-4 sc +++ +++ + >20 wks ----
ML-5 sc ++ +++ ---- >20 wks ----
  1. a SIV/ML-1 to SIV/ML-5 are macaques that were SIV-infected, then 393 days later, they were ML29-infected via a subcutaneous (sc) route. SIV/ML-6 to 8 were similarly SIV-infected, but then vaccinated with ML29 by an intragastric (ig) route. SIV/ARM-1 to 3 were SIV-infected and inoculated over a year later with LCMV-Armstrong by the subcutaneous route. Monkeys ML-1 through ML-5 were never SIV-infected and were all inoculated sc with ML29 only.
  2. b IFNγ responses for 8 SIV/ML animals, SIV/ARM animals and 5 ML29-vaccinated animals were followed up to 22 weeks. Primary arenavirus-specific responses were measured by IFNγ intracellular staining: maximum staining (+++++) corresponds to 0.4% of CD8+ cells, and minimum staining (+) corresponds to 0.012%. Since staining was negligible for CD4+ lymphocytes, measurements are only shown for CD8+ lymphocytes. (− − −) means non-detectable.
  3. c Arenavirus-specific antibody responses were measured by ELISA. The minimum and maximum optical density readings at 450 nm were 1.2 and 2.9 at 1:100 dilution, respectively. OD higher than 0.5 was considered positive.
  4. d Viremia in plasma of 3 ML29-vaccinated animals refers to the transient presence of infectious ML29 particles detected by conventional plaque assay. By sensitive 2-step co-cultivation assays, none of the other SIV-infected animals had detectable ML29 in plasma or urine. (+) in two non-SIV-infected monkeys means the plasma of these animals had co-cultivation-detectable ML29 in plasma (week 1 for ML-3 and week 2 for ML-4).
  5. e Time of euthanasia for those animals that lost more that 10% of body weight.
  6. f SIV viral loads. Animals were classified as Rapid AIDS progressors (R) with >106 viral particles/ml; Medium, (M) between 105-106 viral particles/ml; and Slow (S) with <105 viral particles/ml.