The invention relates to the use of monoclonal antibodies which are specific for CD28 and activate the T lymphocytes of several up to all subgroups without the occupation of an antigen receptor of the T lymphocytes and which therefor activate said lymphocytes in an antigen unspecific manner or the invention relates to the use of an analogue thereof for producing a pharmaceutical composition in the form of a preparation or a preparation packet for treating virus infections in humans or lower warm-blooded animals having infected T lymphocytes. The pharmaceutical composition additionally contains a virus inhibitor. The invention also relates to a corresponding pharmaceutical composition and a treatment plan including the pharmaceutical composition.
