One hundred eighty three infants were intracutaneously inoculated 6 months after the epidemic with A/Asia/57 influenza vaccine with the titer of 300 cc A. 2 times in a 2-week interval in A Group each 0.1 cc 2 times, in the other B Group 0.1 cc and 0.2 cc 2 times, in order to assess the grade of antibody production and side ffects.
The results were as follows;
1) Over 4 times increase of antibody titer was recognized after 4 weeks; HI in all cases of A and B Group of 73 infants investigated, CF in 34 out of 39 cases (87.2%)
2) No significant difference was observed between the shift of HI titer in 48 infants having suffered from influenza during the last epidemic and hat after the vaccination in the same infants.
3) Over one hundred twenty eight times HI titer was demonstrated 17 weeks after the vaccination in all of the 19 cases obviously infected by influenza, whereas a decrease till 64 times was noted in 3 cases probably non-infected.
4) No relationship was recongnized between the rise of HI and CF iter after the vaccination. Over one half of the cases regarded as infected and non-infected during the epidemic or the cases developing no influenzalike disease demonstrated over 8 times great a CF titer in 17 weeks.