The present invention aims to produce a safe and reliable medical composition, which efficiently boosts nonspecific immunity of antigen-presenting cells and thereby promotes an antitumor activity. To produce the medical composition, antigen-presenting cells such as dendritic cells are exposed to an activating reagent containing baculoviruses. Then, the antigen-presenting cells are separated from the activating reagent. The antigen-presenting cells are optionally cultured after the separation. Furthermore, an absence of the baculoviruses in the composition are optionally checked. The medical composition produced by the present invention is expected to have an outstanding therapeutic effect.
