The invention can be used in medicine and veterinary science to create a drug which can be used effectively in oral from in the treatment of a plurality of viral infections, such as influenza, herpes and cytomegalovirus. The modified peptides with antiviral properties and the method for the production thereof are characterized in that the main active agent is a mixture (ensemble) of oligopeptides that are the products of protein hydrolysis and the charges of the molecules of which are changed to an opposite charge, and that in order to produce said oligopeptides, first the partial hydrolysis of a protein-containing raw material is carried out, then a process of chemical modification of the sum of the resultant oligopeptides is carried out with the charge of the molecules thereof being changed to an opposite charge a composition consisting of the resultant oligopeptides is used as the antiviral agent. This sum of modified oligopeptides is capable of inhibiting the activity of the importin-beta heterodimer of a cell and inhibiting the replication of viruses with a replication cycle that is dependent on the functions of the nucleus. The ensemble of modified oligopeptides, based on a dynamic, self-organizing system, is effective in the treatment of viral infections, such as influenza, herpes and animal disease viruses, at all stages in the development of the infectious process when other drugs are ineffective. The agent has a broad spectrum of action and low toxicity, is suitable for industrial production and is effective at all stages in the replication cycle of viruses with a replication cycle that is dependent on the cellular nucleus.Изобретение может быть использовано в медицине и ветеринарии для создания препарата, эффективного при пероральном использовании в лечении многих вирусных инфекций, таких как грипп, герпес, цитомегаловирус. Суть изобретения: модифицированные пептиды с антивирусными свойствами и способ их получения, отличающиеся тем, что в качестве основно
