Field Trials of Live Influenza Vaccine Carried out in November 1964

Abstract

Field trials of live influenza vaccine, produced in our laboratory, were carried out in Osaka in November 1964. Febrile reactions were observed in 262 out of 13, 894 persons (1.9%) and mean maximal fever was 37.6°C. Mean incubation period and duration of fever were 20.1 and 12.5 hours respectively. Persons needed to stay away from work or school were 101 (0.7%) and mean period to be away from work was 1.4 days. Lassitude, headache, rhinorrhea, pharyngeal pain and cough were observed in 3.0%, 4.5%, 1.6%, 1.7% and 1.8% respectively. No differences were observed in clinical reactions between adults and children. Four fold or higher HI antibody response was observed in 31 out of 73 susceptible persons (44%).