Q fever vaccines: present status and application in man.

Of three Q fever vaccine candidates available at present, i.e., phase I corpuscular untreated, soluble, and phase I corpuscular chloroform-methanol treated vaccines, the first two were tested on hundreds of subjects exposed to Q fever. Based on their sufficient immunogenicity (which depends also on the tests employed) and low reactogenicity (providing that subjects with previous contact with Coxiella (C.) burnetii are excluded from vaccination) these two vaccines can be recommended for vaccination of humans at risk. Further studies are required, however, to answer definitively which vaccine type is the most suitable, and facing the problem of C. burnetii strain heterogeneity, to decide whether a monovalent vaccine will be sufficient or a polyvalent vaccine will be necessary.