The variety of responses within a community to infection with Australia (hepatitis B) antigen.

There is a striking difference in the response of individuals to infection with HBV. Some individuals develop hepatitis, others form antibody which may persist for a long period, and others may become persistent carriers of Australia antigen. These responses may give some indication of the immune status of an individual and of populations relative to this agent. As such, it could provide a guide to the use of vaccines against hepatitis in areas of common occurrence of the disease. We have completed a survey of a community in northern Greece for the three factors. A very large percentage of the population have evidence of exposure and this varies with age and sex. Many responded by forming high titers of antibody but a considerable percentage developed hepatitis and/or became carriers. Some appeared to have complex. Most developed antibody against the prevalent antigenic type (ay) but in many cases antibody against the rare antigenic type (ad) appears to have been formed. Host characteristics appear to have influenced the nature of the response to the infection. The effects of vaccines on carriers is not known and conceivably could be detrimental (i.e. by formation of complexes). It would be important to learn more of the biology of Au in populations and individuals in connection with the widespread use of vaccines.