high cost of H1N1 swine flu vaccine in Japan

I am a doctor, working for a clinic in Osaka. I see many patients every day. Today I saw one of my patients, who suffers from a pulmonary disease. He said he couldn’t afford a H1N1 swine flu vaccine, because it is too expensive. A flu vaccine costs 3,600 yen, 40 dollars a shot. One report said that 61% of people, whose annual income was below five million yen, thought they could afford it if it cost 2,000 yen or less.

I know it is free in other developing countries. Why is the cost so high in Japan? I think it is not ethical that one’s economical condition determines the medical service that one can take.