The Effect of Immunization Against Influenza on an Epidemic of Respiratory Illness in Children

It is suggested that the influenza virus A epidemic in and around Boston in late January, February and early March of 1953 was effectively controlled among children in a private pediatric practice by vaccination, and with a minimum of systemic reaction. In a group of 128 children immunized from 1 month to 4.3 years previously, 1 developed what was apparently a moderate or severe form of influenza. In a group of 161 children previously immunized and recently given a booster injection, 1 developed what apparently was a moderate form of influenza. None of 241 patients receiving two doses of 0.03 ml of influenza virus vaccine A and B intradermally and 0.5 ml subcutaneously at weekly intervals just before the epidemic developed an infection. There were 7 patients with influenza among a group of 61 children who received only one small (0.03 ml) intradermal dose of influenza vaccine; 6 of these became ill within 7 days and the other, 11 days after the injection. Twenty-one of one hundred twenty-two children, not given influenza virus A vaccine immunizations, became ill with a moderate or severe form of influenza during this epidemic.