[The protective effect of an EDTA-sodium-extract-vaccine obtained from swine-pathogenic E. coli in a field trial. 2. Communication: Immunization of weanling piglets (author's transl)].

Pentavalent EDTA-Sodium-extract vaccines and monovalent EDTA-Sodium-extract vaccines obtained from swine-pathogenic E. coli were used to test their antiepizootic effect in industrial pig farms, 2929 piglets after weaning were included in this field trial, 1309 were immunized partly orally, partly i.m., 1620 piglets received placebos accordingly. By means of oral immunization the pentavalent vaccine was capable of reducing the morbidity of the vaccinated animals significantly. Intramuscular immunization with the pentavalent vaccines produced significant differences in morbidity too. A monovalent vaccine obtained from E. coli O149 and E. coli O8 was shown to be equally effective, whereas a monovalent vaccine obtained from E. coli O115 was ineffective. But in this stock there were infections with O149 but none with O115 or O8.