rDEN4delta30-200,201

rDEN4delta30-200,201 is a live attenuated dengue virus type 4 (DENV-4) vaccine candidate specifically designed to further attenuate the rDEN4Δ30 parent virus. It contains alanine substitutions at amino acid positions 200 and 201 of the NS5 proteins, which were introduced to decrease hepatotoxicity. In clinical trials, the vaccine infected all vaccinees and was well tolerated without inducing alanine aminotransferase (ALT) elevations. Although virus was not recovered from the serum of any vaccinee, moderate levels of neutralizing antibody were induced in all volunteers. The restricted replication of rDEN4Δ30-200,201 previously documented in animal models was confirmed in humans, making it a promising candidate for inclusion in a tetravalent dengue virus vaccine.