Japanese encephalitis virus infection in South-East Asia: An immuno-epidemiological twist

Background:Japanese encephalitis (JE) is one of the most important zoonotic diseases in a cosmopolitan manner.  Japanese encephalitis virus (JEV) infection represents at least 70 % of emerging diseases caused by the mosquito-borne  JEV. Nearly 20-30% of case fatality corroborated in JEV infections with 30-50% neurologic and psychiatric disorders. A strong epidemic distribution is observed mainly in South-East Asia, demonstrating typical seasonal characteristics and occasional outbreaks. Depending on the genetic diversity, geographical distribution, and emerging natures of JEV, the disease surveillance, and immunization strategies are also varied. Uncontrolled population growth, haphazard agro-animal farming, and ecological imbalance steer the emergence and reemergence of JEV occurrences. Some murine models elucidate the immunological phenomena of JEV infections, the more detailed pathogenesis depending on the genetic variation is yet to be well defined. And the immune-epidemiological traits also address significant concerns regarding the effective vaccines and immunotherapeutics against JEV infections. Therefore, we summarized some critical notions on molecular epidemiology, immunogenicity, and genetic variance of JEV in South-East Asia

Development of seasonal influenza virus-like particle (VLP) vaccines using insect cell-based baculovirus expressing system

[[abstract]]Intro: Influenza viruses are highly infectious and cause widespread respiratory diseases. Moreover, it could pose a noteworthy epidemic and pandemic threat to public health. Vaccination is the most cost-effective intervention to prevent influenza and its complications. Currently, most commercial influenza vaccines are produced using embryonic chicken eggs (ECE), which is hard to scale up efficiently and could potentially reduce vaccine efficacy due to gene mutations in HA genes. In addition, the egg-based technology is associated with some jeopardy of allergic reactions and there is a risk of disrupted egg supply when avian influenza outbreaks erupt. To overcome the dependency on ECE, developments of influenza vaccines based on efficient and robust production platforms are urgently needed. Methods: Several potential vaccine production systems already have shown potential as replacers, including a virus-like particle (VLP) platform. In the current study, using a Baculovirus Expression System (BES), we engineered HA, NA, and M1 genes of influenza A/H1N1, A/H3N2, B/Yamagata-like, and B/Victoria-like virus strains (A/Hawaii/70/2019, A/Minnesota/41/2019, B/Brisbane/09/2014 & B/Brisbane/63/2014) to produce VLP vaccine antigens H1N1-VLP, H3N2-VLP, Yamagata-VLP, Victoria-VLP, respectively. Then functional and antigenic features were determined, including hemagglutination assay, protein composition, size, and morphology of the VLP antigens. Findings: We found that these recombinants VLPs contained influenza HA, NA, and M1 with functional activity, resembled influenza virions in morphology and size, and were structurally intact. We compared the immunogenicity of in-house VLP antigens and commercial recombinant HA (rHA) vaccines in mice. Results revealed that our recombinant VLP antigens are highly immunogenic and produced higher hemagglutination inhibition and virus neutralization antibody titers than the commercial rHA vaccine. Conclusion: The insect cell-based seasonal influenza VLP vaccine antigens are more immunogenic than rHA antigens. Further animal challenge studies are worth to conduct