EN
Vaccines against C. perfringens type C necrotic enteritis, pleuropneumonia, atrophic rhinitis, enterotoxic E. coli infections, erysipelas, Streptococcus suis infection, M. hyopneumoniae infection, dysentery, salmonellosis, porcine proliferative enteritis, leptospirosis were classified in relation to high, medium and low efficacy. The differences were referred to properties of the etiological agent and pathogenesis of the disease. The importance for vaccine efficacy of the pathogenicity factors such as adhesions, toxins and resistance to antibacterial activity of the host, was stressed.