A novel bicistronic DNA vaccine with enhanced protective immune response against Bacillus anthracis through DNA prime-protein boost vaccination approach

Anthrax: A narrative review

Bacillus anthracis is a zoonotic bacterium, majorly responsible for causing human anthrax and the possibility of the outbreak spreading globally. Herbivorous animals serve as the inherent reservoir for the disease, whereas all endothermic species are vulnerable. Humans contract the disease inadvertently by contact with diseased animals or animal products or through the consumption or handling of infected flesh. There is no such reported data indicating the transmission of anthrax from human to human, which further does not guarantee the bacterium's mutations and new transmission route. Nevertheless, it can lead to various infections, including endophthalmitis, bacteremia, cutaneous infection, central nervous system infection, and pneumonia. Therefore, it is crucial to examine the present epidemiological situation of human anthrax in densely populated nations, including the altered symptoms, indications in people, and the method of transmission. This article highlights the current diagnostic methods for human anthrax, further examines the available therapy options and future perspectives in treatment protocol. This narrative review resulted from a simple search strategy on "PubMed", "ScienceDirect", "ClinicalTrials.gov" and web reports using "AND" as Boolean operator with search keywords, i.e., "Anthrax" AND "Infection", "Anthrax" AND "Pandemic", "Anthrax" AND "Infectious disease", "Anthrax" AND "Vaccine", "Anthrax" AND "Diagnosis" shows minimal narrative literature in between 2024 and 2005. Furthermore, this narrative review highlights the potential approaches for detecting anthrax infection, establishing suitable protocols for prevention, and focusing on the current epidemiology and available therapeutics, vaccine and its future developmental strategies for the prevention of infectious disorder.

Production and evaluation of three kinds of vaccines against largemouth bass virus, and DNA vaccines show great application prospects

Largemouth bass virus (LMBV) infections has resulted in high mortality and economic losses to the global largemouth bass industry and has seriously restricted the healthy development of the bass aquaculture industry. There are currently no antiviral therapies available for the control of this disease. In this study, we developed three types of vaccine against LMBV; whole virus inactivated vaccine (I), a subunit vaccine composed of the major viral capsid protein MCP (S) as well as an MCP DNA vaccine(D), These were employed using differing immunization and booster strategies spaced 2 weeks apart as follows: II, SS, DD and DS. We found that all vaccine groups induced humoral and cellular immune responses and protected largemouth bass from a lethal LMBV challenge to varying degrees and DD produced the best overall effect. Specifically, the levels of specific IgM in serum in all immunized groups were elevated and significantly higher than those in the control group. Moreover, the expression of humoral immunity (CD4 and IgM) and cellular immunity (MHCI-α) as well as cytokines (IL-1β) was increased, and the activity of immunity-related enzymes ACP, AKP, LZM, and T-SOD in the serum was significantly enhanced. In addition, the relative percent survival of fish following an LMBV lethal challenge 4 weeks after the initial immunizations were high for each group: DD(89.5 %),DS(63.2 %),SS(50 %) and II (44.7 %). These results indicated that the MCP DNA vaccine is the most suitable and promising vaccine candidate for the effective control of LMBV disease.

Heterologous Prime-Boost Immunization with DNA Vaccine and Modified Recombinant Proteins Enhances Immune Response against Trueperella pyogenes in Mice

Trueperella pyogenes (T. pyogenes) is a crucial opportunistic pathogen normally causing mastitis, abscesses and pneumonia in economically important ruminants. Although only one commercial vaccine of T. pyogenes is currently obtainable, its immunoprotective effect is limited. Pyolysin (PLO) is the most predominant virulence factor highly expressed in T. pyogenes and is an excellent target for the development of novel vaccines against T. pyogenes. In this study, we designed a heterologous prime-boost vaccination scheme combining a DNA vaccine pVAX1-PLO and a subunit vaccine His-PLO to maximize host responses in mice. Humoral and cellular immune responses and protective effects were evaluated in mice to compare the immunogenicity induced by different immunization schemes. Compared to the PBS-control group, in vivo immunization results showed that better immune responses of mice immunized with the pVAX1-PLO plasmids and His-PLO proteins were induced. The residual bacterial burdens from the liver and peritoneal fluid were remarkably decreased in the immunized mice compared with the PBS group. Notably, the heterologous prime-boost vaccination groups significantly enhanced host humoral and cellular immune responses and protected mice from different virulent T. pyogenes strains infection. Conclusively, this study provides a favorable strategy for the further development of next-generation vaccines against T. pyogenes infections.