Recently the Jiji News reported the following:
The Health Minister announced on the 11th that they had been formally decided on one-dose vaccination regarding the vaccination for the new influenza, except for the age group below the high school student. Up to this moment, the principle was to go for two-dose vaccination. Based on the result obtained from the clinical trial on immunity, one-dose or two-dose had hardly showed any difference, as such specialists came to the conclusion that one-dose vaccination would be enough. The vaccination schedule could be moved up by this decision. But, as there was the possibility of vaccinating the healthy adults who all along were outside the vaccination schedule, on top of the delay in actual vaccination, they might be lacking behind in coping with the arrival of the peak of the new influenza. According to the Ministry of Health, Labour and Welfare, people who had chronic disease, pregnant women, senior citizens, and guardians of baby below one-year-old would be vaccinated once. Children of less than 13-year-old would receive twice because there was a possibility that they were without the basic immunity, also, people who had chronic disease and their immune status had deteriorated might receive twice depending on the doctor's judgment. Moreover, the junior high school and the high school student would now go ahead with two-doze vaccination, but by the end of December upon the release of the clinical trial result, a decision would be made on whether one-dose vaccination would suffice.
From the above we can see that Japan is fine-tuning its vaccination strategy in response to the new type influenza.