Abstract: | The comparative study of the dynamics of morphological changes in tissues of guinea pigs after the subcutaneous injection of chemical, live and combined vaccines against Q fever during the period from 12 hours to 90 days was made. All vaccines under study were shown to produce a pronounced local damaging effect. Two periods were tentatively discriminated in the dynamics of changes: the early phase (till 48 hours) and the late phase (days 2-90). At the early stage the most pronounced changes were registered after the injection of the combined vaccine. At the late phase the use of the chemical and combined vaccines was accompanied by the appearance of secondary hemorrhages into newly formed connective tissue. Starting from day 30, practically no deviation from the normal state of tissues were registered at the site of injection. |