Abstract
A method is described for producing monovalent and polyvalent vaccines from culture filtrates of K. aerogenes. With a single injection, each monovalent vaccine protected mice against lethal i.p. challenge by > 30 capsular types; polyvalent vaccines containing 2-12 monovalent components protected against 46-61 of the 77 capsular types of K. aerogenes. One vaccine with 12 components, administered in 2 doses, induced full protection against 71 types and protected half of the mice challenged with the other 6 types.