Problematic questions in the development of specific prevention of dengue fever

Dengue fever known from literary sources since the Qin dynasty (265-420) is caused in humans when bitten by Aedes mosquitoes infected with the dengue virus (DENV) and manifests as a flu-like disease. A feverish state can be accompanied by dyspeptic disorders (nausea, vomiting, diarrhea) and a rash. Approximately 1-2% of infections are clinically presented as the most severe form – it is dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) leading to 500 thousand annual hospitalizations with a mortality rate of about 5% in endemic areas.Four genetically removed DENV serotypes (1, 2, 3, and 4) are classified as different types of viruses within the same antigen complex and have almost identical epidemiological features. In 2013 a new serotype DENV-5 was isolated.Until the 1980s in most geographical regions of the world where dengue fever was registered only one or two viral serotypes were detected as an etiological agent of the disease. Over time there is an increase in the cocirculation of four types of viruses which can serve as a key indicator of their global spread. As the “traces” of the four DENV species overlap more and more the threat of severe disease increases due to the phenomenon of antibody-dependent of infection when re-infected with a heterologous viral serotype.Development of specific dengue fever prevention has been underway since 1944 (since the discovery of viral agents of this disease) but the first and so far only licensed in 2015 tetravalent vaccine-Dengvaxia developed by the French pharmaceutical company Sanofi Pasteur has been effective in varying degrees of protection against infection with each of the viral serotypes and in addition dangerous for previously seronegative people. Research aimed at obtaining a safe and effective vaccine is continuing. Neutralizing monoclonal antibodies are a necessary tool for studying the antigenic structure of viral immunogens as base of prevention preparates against dengue fever

MONOCLONAL ANTIBODIES AND RECOMBINANT PROTEINS OF FILOVIRUSES: IMMUNOCHEMICAL PROPERTIES AND EVALUATION OF THEIR EFFICIENCY FOR IMMUNE DIAGNOSTICS OF MARBURG AND EBOLA VIRUSES

A panel of monoclonal antibodies (MAbs) against VP35, VP40 and NP viral proteins of Marburg and Ebola viruses, as well as recombinant VP35, VP40 and NP proteins were generated and tested for their capacity to specific immune reactions. Monoclonal antibodies to appropriate viral proteins effectively recognized the VP35, VP40 and NP recombinant proteins, thus allowing to develop a variant of a MAb-based ELISA analysis with different types of biotin-labeled MAbs, using these antibodies for capturing viral and recombinant antigens of Marburg and Ebola viruses. These techniques were able to detect viral and recombinant proteins in a concentration range between 1 and 150 ng/ml. We conclude that the recombinant VP35, VP40 and NP proteins of filoviruses, as well as MAbs against these viral proteins represent a promising tool for a new generation of immunodiagnostic kits and studying immunological features of filovirus infection

Are Hamsters a Suitable Model for Evaluating the Immunogenicity of RBD-Based Anti-COVID-19 Subunit Vaccines?

Currently, SARS-CoV-2 spike receptor-binding-domain (RBD)-based vaccines are considered one of the most effective weapons against COVID-19. During the first step of assessing vaccine immunogenicity, a mouse model is often used. In this paper, we tested the use of five experimental animals (mice, hamsters, rabbits, ferrets, and chickens) for RBD immunogenicity assessments. The humoral immune response was evaluated by ELISA and virus-neutralization assays. The data obtained show hamsters to be the least suitable candidates for RBD immunogenicity testing and, hence, assessing the protective efficacy of RBD-based vaccines