Preclinical and clinical development of preventive rotavirus vaccines: special considerations

INTRODUCTION . Vaccination is recognised as the only effective method for preventing rotavirus disease. Rotavirus remains a leading cause of death in young children, mainly, in developing countries. Currently, oral rotavirus vaccines for infant immunisation are available worldwide, and novel types of rotavirus vaccines are also under development, in particular, in the Russian Federation. However, there are no regulations or guidelines helping developers to design an optimal preclinical and clinical programme for rotavirus vaccines. AIM. This study aimed to analyse and summarise global experience in planning and conducting preclinical and clinical studies of rotavirus vaccines in order to provide recommendations for national vaccine developers. DISCUSSION. This study presents an analysis of the available data (and, specifically, the data obtained for the past five years) on all rotavirus vaccines used in the world that have been clinically proven to be effective in preventing severe rotavirus gastroenteritis and reducing the number of hospital admissions due to acute intestinal infections. The effectiveness of rotavirus vaccines varies in different regions of the world and may be lower in developing countries for various reasons. The safety profile of oral rotavirus vaccines is generally considered favourable. Nevertheless, there are still some concerns regarding intestinal intussusception in infants following vaccination. To address the abovementioned problems, researchers, including those in Russia, are developing novel types of rotavirus vaccines, predominantly focusing on inactivated (subunit or recombinant) preparations. For planning and conducting preclinical studies of a rotavirus vaccine, it is advisable to adopt general approaches that involve assessing the acute and chronic toxicity, immunogenicity, and safety pharmacology of the rotavirus vaccine and the virus-neutralising activity of vaccination-induced antibodies. Clinical trials of a rotavirus vaccine should assess its effectiveness in preventing rotavirus gastroenteritis of any severity, hospitalisation, and acute viral intestinal infections of any aetiology in the target age group of young children. Furthermore, it is important to confirm the safety of the rotavirus vaccine and demonstrate the absence of mutual interference with the immunogenicity of the rotavirus vaccine and other vaccines co-administered in the vaccination schedule. CONCLUSIONS . Preclinical studies of rotavirus vaccines may use standard and generally accept­ed approaches. However, planning and conducting clinical trials requires specific considerations associated with both the nature of rotavirus infection and the national infant vaccination schedule.