Non-Glycosylated SARS-CoV-2 Omicron BA.5 Receptor Binding Domain (RBD) with a Native-like Conformation Induces a Robust Immune Response with Potent Neutralization in a Mouse Model.

The Omicron BA.5 variant of SARS-CoV-2 is known for its high transmissibility and its capacity to evade immunity provided by vaccine protection against the (original) Wuhan strain. In our prior research, we successfully produced the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein in an E. coli expression system. Extensive biophysical characterization indicated that, even without glycosylation, the RBD maintained native-like conformational and biophysical properties. The current study explores the immunogenicity and neutralization capacity of the E. coli-expressed Omicron BA.5 RBD using a mouse model. Administration of three doses of the RBD without any adjuvant elicited high titer antisera of up to 7.3 × 105 and up to 1.6 × 106 after a booster shot. Immunization with RBD notably enhanced the population of CD44+CD62L+ T cells, indicating the generation of T cell memory. The in vitro assays demonstrated the antisera's protective efficacy through significant inhibition of the interaction between SARS-CoV-2 and its human receptor, ACE2, and through potent neutralization of a pseudovirus. These findings underscore the potential of our E. coli-expressed RBD as a viable vaccine candidate against the Omicron variant of SARS-CoV-2.

The Immunogenicity of DENV1-4 ED3s Strongly Differ despite Their Almost Identical Three-Dimensional Structures and High Sequence Similarities.

The development of a dengue (DENV) vaccine remains challenging due to the heteroserotypic infection, which can result in a potentially deadly hemorrhagic fever or dengue shock syndrome, and only a tetravalent vaccine can overcome this issue. Here, we report the immunogenicity of DENV envelope protein domain 3 (ED3) from all four DENV serotypes (DENV1-4) in Swiss albino and BALB/c mice models. Firstly, we observed that despite having very similar sequences and structures, both the humoral and cellular immunogenicity of ED3s varied significantly, with strength ranging from DENV2 ED3 (2ED3)~3ED3 > 1ED3 > 4ED3, which was assessed through anti-ED3 IgG titers, and DENV1 ED3 (1ED3) > 2ED3~3ED3 > 4ED3 as determined by monitoring T-cell memory (CD44+CD62L+ T cells with IL-4 and IFN-γ expression). Secondly, anti-1ED3 sera cross-reacted with 2ED3 and 3ED3; anti-2ED3 and anti-3ED3 sera cross-reacted with each other, but anti-4ED3 was completely serotype-specific. The lack of reciprocity of anti-1ED3's cross-reaction was unanticipated. Such disparity in the ED3 responses and cross-reaction might underlie the appearance of hemorrhagic fever and dengue shock syndrome. Hence, the development of an ED3-based tetravalent subunit vaccine would require understanding the aforementioned disparities.

How indebted farmers perceive and address financial risk in environmentally degraded areas in Bangladesh.

In Bangladesh, the recent uncontrolled growth of industries near farmland and unplanned urbanization made the agricultural sector the most vulnerable and a massive threat to the food security of the country. Agricultural farms near to industrial zones face high production costs (poor air-water-soil quality, high labor cost) and low-profit margin (poor crop yield and crop loss due to frequent natural hazards). The government policy in this matter is not proper due to a lack of information. As a consequence, many of these farm owners adopt agricultural credit by themselves to manage the production cost. Basically, credit itself creates some other financial risks and the farmers needed to adopt different measures to handle these financial risks. In-depth research on this matter is important to improve the situation by providing relevant information that policymakers can plan an efficient policy framework. However, previous literature has overlooked this area of research. In this study, the researcher collected data on 400 rice farmers (debtors) from six different districts in greater Dhaka division (most degraded area in Bangladesh) and adopted probit model to analyze the influential factors affecting farmers' financial risk management adoption decision and to identify the correlations between these decisions. The empirical findings indicate that education, access to technologies, household income, savings, and distance from the industrial areas are the major factors that affect farmer's adoption choice and most of the farmers are risk-averse. Moreover, the adoption choice of one risk management tool may motivate farmers to adopt another.