Influenza viruses continue to undergo antigenic drift and shift, resulting in the need to update existing vaccines annually. Therefore, the development of a universal influenza vaccine has become an urgent global need. This paper reviews the functions of common antigenic targets of influenza vaccines and their advantages and disadvantages in universal vaccine design. We also summarize the common design strategies for universal influenza vaccines, which mainly include the immunofocusing strategy, multi-target combination strategy, T-cell strategy, computationally optimized broadly cross-reactive antigenic strategy (COBRA), and artificial intelligence strategy. In addition, we also sort out the latest research progress of universal influenza vaccines under different technological routes. This will help researchers better grasp the latest developments of universal influenza vaccines.

Hepatitis E virus (HEV) is a zoonotic pathogen and the main cause of acute viral hepatitis in China, resulting in a significant burden on public health. Developing a highly efficient in vitro culture system for HEV is crucial for understanding the determinants of HEV infection in humans and other animals, the pathogenic mechanisms, as well as the screening and evaluation of antiviral drugs. In this paper, the research progress on HEV in vitro culture systems is reviewed to provide a convenient reference for further research on HEV, aiding comprehensive efforts toward the widespread prevention and control of related diseases.

Objective: Establish an in vivo evaluation model focused on the attachment and entry stages of Hendra virus infection for protective immunity assessment. Methods: A golden hamster infection model based on recombinant Hendra-F/G pseudovirus was developed, and a luciferase luminescence assay was used to assess the optimal pseudoviral challenge in terms of route of infection, dose and detection time. The biodistribution of the pseudovirus in infected organs was evaluated using the IVIS spectral CT system. The protective effect of antibody prophylaxis was evaluated by measuring the luminescence intensity of pseudoviruses. Results: Intraperitoneal injection was identified as the optimal route of infection, and the optimal time of detection was 6 h post-challenge. Our model simulates the infection of the brain and lungs by live viruses, with the strongest infection occurring in the abdomen, especially in the intestinal organs. The dose of pseudovirus was linearly correlated with luminescence intensity. The infection model was able to differentiate the protective effect of monoclonal antibodies, with complete protection in the high-dose group. Conclusions: The recombinant Hendra-F/G pseudovirus hamster model allows the effective evaluation of prophylactic monoclonal antibodies, providing a crucial tool for studying Hendra virus infection and control strategies.

The high case fatality rate, cross-species transmission, and ongoing evolution of H5 avian influenza viruses pose an imminent threat of an influenza pandemic, particularly with the currently predominant clade 2.3.4.4b lineage. Existing seasonal influenza vaccines and licensed H5 vaccines provide limited cross-protection against H5 viruses, underscoring an urgent need for the development of broadly protective H5 vaccines. In this study, we analyzed all human-infected H5 hemagglutinin (HA) sequences using bioinformatics approaches and subsequently designed a novel H5 influenza vaccine through algorithm optimization. The predicted structure of this vaccine closely resembles that of the wild-type H5 HA trimer. In animal studies, the algorithm-optimized H5 mRNA vaccine not only induced high levels of neutralizing antibodies against multiple clade 2.3.4.4b H5 viruses but also elicited cross-neutralizing antibodies against clade 2.3.4.4 and clade 2.2.1 H5 viruses, as well as robust cellular immune responses. These findings highlight the potential of algorithm-based approaches in developing broadly protective vaccines against pandemic viruses and suggest that this vaccine candidate could serve as a strategic stockpile for preventing H5 influenza pandemics.