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The live attenuated human rotavirus vaccine strain RIX4414 (Rotarix®) is used worldwide to prevent severe rotavirus-induced diarrhea in infants. This strain was attenuated through the cell culture passaging of its predecessor, human strain 89-12, which resulted in multiple genomic mutations. However, the specific molecular reasons underlying its attenuation have remained elusive, primarily due to the absence of a suitable reverse genetics system enabling precise genetic manipulations. Therefore, we first completed the sequencing of its genome and then developed a reverse genetics system for the authentic RIX4414 virus. Our experimental results demonstrate that the rescued recombinant RIX4414 virus exhibits biological characteristics similar to those of the parental RIX4414 virus, both in vitro and in vivo. This novel reverse genetics system provides a powerful tool for investigating the molecular basis of RIX4414 attenuation and may facilitate the rational design of safer and more effective human rotavirus vaccines. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Most drugs that cause adverse events are difficult to identify in critically ill patients undergoing polypharmacy. We share our experience in identifying the causative drug among four suspect drugs administered during emergency treatment. We present the case of a 93‐year‐old man who was admitted for the treatment of cerebrovascular events. The patient was initially prescribed dual antiplatelet therapy with aspirin and clopidogrel along with lansoprazole, Hange‐koboku‐toh, and elobixibat. On day 36 after admission, the patient was found to have developed agranulocytosis. To improve his cerebrovascular prognosis, we first discontinued medications other than the anticoagulant medicines and initiated filgrastim. We discontinued clopidogrel 9 days after the discontinuation of the other medicines considering his low white blood cell count. One day after the discontinuation of clopidogrel, the agranulocytosis was alleviated. Considering the time course, clopidogrel, lansoprazole, Hange‐koboku‐toh, and elobixibat were suspected as the culprit medicines. This case highlights the considerable challenges encountered in clinical practice when attempting to identify the drugs responsible for agranulocytosis, particularly in patients on intensive medication therapy. [ABSTRACT FROM AUTHOR]

Vaccine development for herpes simplex virus 2 (HSV‐2) has been attempted, but no vaccines are yet available. A plasmid‐based reverse genetics system for Rotavirus (RV), which can cause gastroenteritis, allows the generation of recombinant RV containing foreign genes. In this study, we sought to develop simian RV (SA11) as a vector to express HSV‐2 glycoprotein D (gD2) and evaluated its immunogenicity in mice. We generated the recombinant SA11‐gD2 virus (rSA11‐gD2) and confirmed its ability to express gD2 in vitro. The virus was orally inoculated into suckling BALB/c mice and into 8‐week‐old mice. Serum IgG and IgA titers against RV and gD2 were measured by ELISA. In the 8‐week‐old mice inoculated with rSA11‐gD2, significant increases in not only antibodies against RV but also IgG against gD2 were demonstrated. In the suckling mice, antibodies against RV were induced, but gD2 antibody was not detected. Diarrhea observed after the first inoculation of rSA11‐gD2 in suckling mice was similar to that induced by the parent virus. A gD2 expressing simian RV recombinant, which was orally inoculated, induced IgG against gD2. This strategy holds possibility for genital herpes vaccine development. [ABSTRACT FROM AUTHOR]

The emergence of unusual G9P[8]-E2 human rotaviruses in the Tokyo metropolitan area, Japan, in 2018 has been reported. During rotavirus strain surveillance in different regions of Japan (Mie, Okayama, and Chiba prefectures), G9P[8]-E2 strains were detected in children with diarrhea from all three prefectures. Here, we characterized the whole genome of seven representative G9P[8]-E2 strains. In the full-genome-based analysis, the seven study strains exhibited a unique genotype configuration with the NSP4 gene of genogroup 2 in a genogroup 1 genomic backbone: G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1. This genotype constellation was shared by the Tokyo G9P[8]-E2 strains. Phylogenetic analysis showed that all 11 genes, except NSP4, of the seven study strains appeared to have originated from co-circulating Wa-like G9P[8]-E1 strains. In contrast, NSP4 appeared to have originated from the co-circulating DS-1-like G2P[4]-E2 strains. Thus, G9P[8]-E2 strains appear to be derived through reassortment between G9P[8]-E1 and G2P[4]-E2 strains in Japan. Notably, the seven study G9P[8]-E2 strains and Tokyo G9P[8]-E2 strains were revealed to have 11-segment genomes almost indistinguishable from one another in their sequences (99.3-100%), indicating all these G9P[8]-E2 strains had a common origin. To our knowledge, this is the first description of the rapid spread of G9P[8]-E2 strains across a country.