Olive baboons: a non-human primate model for testing dengue virus type 2 replication

SummaryObjectiveThis study evaluated the use of a non-human primate, the olive baboon (Papio anubis), as a model of dengue infection. Olive baboons closely resemble humans genetically and physiologically and have been used extensively for assessing novel vaccine formulations.MethodsTwo doses of dengue virus type 2 (DENV-2) were tested in baboons: 103 and 104 pfu. Similarly, African green monkeys received the same quantity of virus and acted as positive controls.ResultsFollowing exposure, high levels of viremia were detected in both animal species. There was a trend to detect more days of viremia and more homogeneous viral titers in animals receiving the low viral dose. In addition, baboons infected with the virus generally exhibited positive virus isolation 1 day later than African green monkeys. Humoral responses consisting of antiviral and neutralizing antibodies were detected in all animals after infection.ConclusionsWe conclude that baboons provide an alternative non-human primate species for experimental DENV-2 infection and we recommend their use for further tests of vaccines, administering the lowest dose assayed: 103 pfu