[Comparative study of parenteral and oral immunization to influenza in a large clinical trial. 1. Results of clinico-epidemiologic studies].

360 volunteers were recruited for the investigation from a homologous collective. 174 were immunized parenterally with "Influmun" from SSW Dresden, GDR. 176 volunteers were immunized twice orally with an interval of 60 days with an influenza vaccine inactivated by x-ray using enteric-coated capsules. In an interval of six months ARI-symptoms were investigated. Between 13th and 17th week 1988 an increased ARI-morbidity in the Greifswald-region was observed in which influenza A viruses were involved. In comparison with 312 non-immunized persons of the same age, sex and living area the immunized volunteers of the two groups showed 83.4% less sickness days. 30 persons of the non-immunized group got ill for totally 217 days, whereas only nine persons of the two immunized groups were put on the sicklist for totally 36 days. No significant differences concerning the occurrence and duration of acute respiratory infections (ARI) between the two differently immunized groups could be observed.