Reporting in the Journal of the American Medical Association , a team of researchers from five universities argue that stress can lessen a person's immune response and that change can make them more susceptible to infectious diseases. They also say that increased stress may lessen the effectiveness of certain vaccines and can confound some studies of certain illnesses that affect the immune system, such as AIDS and autoimmune diseases. The JAMA paper points to the important role that compounds known as cytokines play in regulating the immune response. In some cases, they stimulate the release of other compounds essential for inflammation. In other cases, they maintain the balance of other components of the human immune response.
Researchers know that psychological stress can alter the level of certain hormones.
These alterations induced by stress are responsible for the changes in cytokine concentrations since stress hormones alter the synthesis and the release of the cytokines, the authors explained. Glaser suggests that while in vitro tissue cultures have taught us much about the immune response, that system may function differently in the whole animal, or person. The researchers pointed to recent research involving vaccinations for Hepatitis B and for influenza. They showed that stress could suppress T-cell responses and lower antibody levels, two factors necessary to develop a strong immunity to these diseases. Our inference is that a poor immunological response to vaccination has medical consequences.