biostudies-literatureUnknown99(11)Bessey TKVarious vaccines, like polio, measles, and rotavirus, have been developed by serial-passaging in cell culture. Live oral rotavirus vaccines have been shown to be generally safe, but mechanisms of attenuation are not known. We have used a new, entirely plasmid-based reverse genetics system to artificially generate the novel human rotavirus vaccine strain CDC-9 (G1P[8]) and analyze the effect of the mutations within the VP4 gene on adaptation in vitro and attenuation in vivo. We demonstrated that out of the 6 amino acid mutations that appeared after serial passaging in Vero cells, mutations of wild-type CDC-9 P11 at VP4 AA331 and AA385 each or in combination were associated with increased replication in vitro comparable to cell-culture adapted CDC-9 P45. Neonatal rats inJournal of virologye0106725https://www.ebi.ac.uk/biostudies/studies/S-EPMC12645992biostudies-literatureMutations of two amino acids in VP5 mediate the attenuation of human rotavirus vaccine: evidence from in vitro and in vivo studies.PMC12645992Greenberg HBJais PHJiang BBessey TKWang YSanchez-Tacuba LMoon S-SfalseMutations of two amino acids in VP5 mediate the attenuation of human rotavirus vaccine: evidence from in vitro and in vivo studies.Various vaccines, like polio, measles, and rotavirus, have been developed by serial-passaging in cell culture. Live oral rotavirus vaccines have been shown to be generally safe, but mechanisms of attenuation are not known. We have used a new, entirely plasmid-based reverse genetics system to artificially generate the novel human rotavirus vaccine strain CDC-9 (G1P[8]) and analyze the effect of the mutations within the VP4 gene on adaptation in vitro and attenuation in vivo. We demonstrated that out of the 6 amino acid mutations that appeared after serial passaging in Vero cells, mutations of wild-type CDC-9 P11 at VP4 AA331 and AA385 each or in combination were associated with increased replication in vitro comparable to cell-culture adapted CDC-9 P45. Neonatal rats in2025-01-01T00:00:00Z2025 Nov2026-05-20T03:22:35.949Z2026-05-20T03:14:32.2ZS-EPMC126459924106002710.1128/jvi.01067-25