This publication presents an algorithm for selecting immunodominant epitopes that are regions of influenza virus proteins used in vaccination in 2023-2024 for use in immunodiagnostics. Using various remote access programmes, an algorithm for searching for immunodominant epitopes was implemented based on the analysis of the amino acid sequence of virus proteins included in vaccines marketed in the Republic of Belarus. This is a stage before synthesis of peptides for laboratory diagnostics of cellular response of immunity system to virus vaccine. That in the future will allow to use only suitable peptides for diagnostics of postvaccinal immune response. Thus, a different set of peptides allows to detect the response of the immunity system to the surface proteins of viruses from vaccines "Grippol", "Vaxigripp Tetra", "Influvak Tetra" or to other proteins of influenza viruses in case of disease. Which is an additional test after evaluation of the humoral response in the form of neutralising antibodies to haemagglutinin.