Shigella flexneri/sonnei bivalent live vaccine (freeze-dried) (Shigella FS vaccine)

A bivalent oral yeast vaccine displaying Nocardia seriolae FHA and LMBV MCP confers protection in largemouth bass (Micropterus salmoides).

Lu Jianfei J, Gu Boge B, Yu Pengzhen P, Chen Jiong J

Largemouth bass ranavirus (LMBV) and Nocardia seriolae are major pathogens affecting largemouth bass (Micropterus salmoides), causing significant economic losses. In this study, recombinant yeasts expressing the fibronectin-binding protein A (FHA) of N. seriolae or the major capsid protein (MCP) of LMBV were constructed using the yeast surface display (YSD) system. Based on these recombinant strains, a bivalent oral yeast-based vaccine was developed and its protective efficacy was systematically evaluated. Oral administration of the vaccine induced specific antibodies against FHA and MCP in serum, as well as increased the transcription levels of adaptive immune genes (IgM, IgT, MHC-II) and innate immune genes (IL-1β, TNF-α, IFN-1, Mx2) in the hindgut, liver, and spleen. Importantly, the bivalent oral vaccine provided significant protection against both pathogens in largemouth bass, with relative percent survival (RPS) values of 56.7% against N. seriolae and 63.3% against LMBV. Meanwhile, the oral vaccine reduced pathogen loads and alleviated histopathological lesions. In summary, these findings suggest that the bivalent oral vaccine developed in this study could serve as a promising strategy for controlling N. seriolae and LMBV infections in largemouth bass aquaculture.

Correction: Economic evaluation of including the EV71 vaccine in the national immunization program: a modeling study in Guangxi, China.

He Quan Q, Liao Xiaoting X, Deng Linlin L, Su Zhengqin Z et al.

[This corrects the article DOI: 10.3389/fpubh.2026.1842766.].

Barriers to oral healthcare for autistic children in China.

Wang Xing X, Huang Xuchen X

Targeting conserved interaction surfaces of alphavirus nsP4 supports the rational design of live-attenuated vaccine candidates.

Yang Xiaoyao X, Väljaots Evelin E, Li Kaiyu K, Naumenko Krystyna K et al.

Alphaviruses are emerging arboviruses that pose a growing threat to global public health; however, effective interventions remain limited. Recent structural studies of the chikungunya virus (CHIKV) replicase core revealed that the viral RNA-dependent RNA polymerase nsP4 interacts with both nsP1 and nsP2 and is predicted to engage viral RNA. The conservation and multifunctionality of nsP4 make it a challenging but promising target for rational attenuation. Here, we evaluated 58 structure-guided mutations in nsP4 predicted to disrupt interactions with nsP1, nsP2, or viral RNA using a trans-replicase system. Sixteen selected mutations were further analyzed in a CHIKV-o'nyong-nyong virus chimera and Semliki Forest virus (SFV). Most mutants were viable but showed varying degrees of attenuation in mammalian and mosquito cells. Viruses carrying mutations in predicted RNA-interaction sites frequently acquired pseudoreversions and/or second-site compensatory changes, whereas those harboring mutations affecting nsP1 or nsP2 interfaces were more genetically stable. Three substitutions representing defects in nsP1 interaction (F164A), predicted RNA interaction (K174S), and nsP2 interaction (D393A) were further characterized in authentic CHIKV and displayed attenuation consistent with that observed in SFV. In vivo, all three variants showed reduced pathogenicity in the SFV mouse model, with F164A being avirulent, immunogenic, and conferring complete protection against lethal challenge. In a CHIKV mouse model, these mutations attenuated disease and reduced serum virus titers and inflammatory cell infiltration. Together, these findings provide a molecular framework for the rational design of live-attenuated alphavirus vaccine candidates and support broader evaluation of nsP4-based attenuation. Alphaviruses are an increasing global health concern, with hundreds of thousands of chikungunya cases reported worldwide in 2025; however, vaccine options remain limited, and no specific antiviral treatment is available. Recent structural studies have revealed conserved functional interfaces in the viral RNA polymerase nsP4, but their value for attenuation had not been systematically explored. Here, using structure-guided mutagenesis, validation in multiple viral systems, and in vivo analysis, we show that selected nsP4 mutations can strongly attenuate replication and pathogenicity while preserving immunogenicity. These findings identify conserved nsP4 interfaces as a shared vulnerability of alphaviruses and provide a molecular framework for the rational design of broadly applicable live-attenuated vaccines while also highlighting nsP4 as a functionally constrained target relevant to antiviral development.