INTRODUCTION: Rotovirus infection (RVI) caused by the dsRNA-containing virus from genus Rotavirus, Reoviridae family, belonging to group A (RVA), is the cause of severe diarrhea in human and other mammalian species. Vaccination is the most effective way to reduce the incidence of RVI. At present, the effectiveness of using gnotobiotic piglets as a universal model for reproducing human rotavirus infection and assessing the quality of RVI vaccine preparations has been experimentally proven. OBJECTIVES: Evaluation of immunogenic activity of the cloned RVA Wa strain in the new-born Vietnamese potbellied piglets trial. MATERIAL AND METHODS: Development of viral preparations of the cloned human Wa strain PBA, development of human RVA rVP6, ELISA, polymerase chain reaction with reverse transcription, immunization and experimental infection of newborn piglets. RESULTS: The article presents the results of the experiment on double immunization of newborn piglets with native virus preparations with the infection activity 5.5 lg TCID(50)/ml, 3 cm(3) per dose, HRV with adjuvant 500 microg per dose and mock preparation (control group) followed with experimental inoculation of all animals with virulent virus strain Wa G1P[8] human RVA with infectious activity of 5.5 lg TCID(50)/ml in 5 cm(3) dose. Development of clinical signs of disease and animal death were observed only in control group. RT-PCR system to detect RVA RNA in rectal swabs, samples of small intestine and peripheral lymph nodes was developed. ELISA based on obtained human RVA rVP6 was developed and results on RVA-specific IgG-antibodies in serum samples of experimental piglets are presented. CONCLUSION: In the course of the research, a high immunogenic activity of the native and purified virus of the cloned Wa RVA strain Wa was established and the possibility of its use as the main component of the RVI vaccine was confirmed. The possibility of using conventional newborn pigs instead of gnotobiotic piglets as an experimental model was demonstrated.