Toxicity Evaluation of a VLP-Based Vaccine Аgainst Human Rotavirus Infection Following a Single Administration in Rats: Serum Biochemistry and Histopathological Examination of Organs and Injection Site

Virus-like particle (VLP) - based vaccines exhibit outstanding clinical, epidemiological, and immunological efficacy and specificity. The novel technology used for producing their active component without incorporating live viruses enables both injectable and non-injectable (e.g., intranasal) administration, emphasizing the need for a comprehensive safety assessment. This study is part of a preclinical toxicological evaluation program aimed at assessing the safety profile of the “Gam-VLP-rota” vaccine candidate targeting human rotavirus infection. The goal of this extended toxicology study was to confirm the safety of a single intramuscular administration of the vaccine in Sprague-Dawley rats. The study focused on identifying possible adverse effects both acutely (within 24 hours post-administration) and after a 14-day recovery period, aiming to detect delayed toxicological signs. Toxicological endpoints included evaluation of target organs, coagulation parameters, hematology, clinical biochemistry, necropsy findings, and histopathological analysis. This article presents a segment of the results, including changes in serum biochemical parameters after a single immunization and histological examination of internal organs and the injection site in rats. Keywords: VLP; vaccines; preclinical studies; vaccine safety; toxicological chemistry.