A polyvalent vaccine was prepared from 078: K 80 (B-), 0125: K 70 (B15) and 080: K 61 (B7) and divided into two parts, the first was heat-inactivated and the second was a formalinized 2ed vaccine. The vaccinal dose was one ml. adminsitered either by oral or intramnscular route for both types of vaccine.
The birds challenged, 15-days after the administration of the second vaccinal dose, either by homologous or heterologous strains.
E. coli aglutinating antibodies were detected in the serum of birds with a titres up to 480 following heat inactivated vaccine and up to 320 following formalinized one.
The serum of test group showed a higher titres of antibodies up to 800 following challenge, while no change accurred after herologous challenge.