Abstract: The present inventors have conducted intensive studies on an antibody which controls HIV in an administration group with a high probability over a long period of time with one or several times of single-agent administration. As a result, the present inventors have surprisingly found that, when an SW-1C10 antibody, which is obtained by producing an antibody gene reported as 1C10 in silkworms, is singly administered only a few times, the viral load in the blood is suppressed to the detection limit or lower at an early stage in all of individuals to which the antibody has been administered, and moreover, the viral RNA load in the blood is maintained at the detection limit or lower for a long time of 12 weeks. Also, the yield of the antibody in silkworms is approximately several hundreds ?g per cocoon, or several ?g per 1 mg of cocoon, and studies to increase the productivity more than this level have not been conducted heretofore.