A double-blind prospective design was used to investigate the immediate and prolonged psychological effects of a specific viral infection, and the role of immune activation in mediating these effects. Subjects were 240 female teenager girls who were vaccinated with rubella vaccine. Based on analysis of levels of antibodies to rubella, subjects were divided into two groups. An experimental group (n = 60), which included subjects who were initially seronegative and were infected following vaccination, and a control group (n = 180), which included subjects who were already immune to rubella before vaccination. Compared with the control group and to their own baseline, low socioeconomic status (SES) subjects within the experimental group showed a significant increase in the severity of depressed mood, social and attention problems, and delinquent behavior. Ten weeks post-vaccination there were no differences between the experimental and control groups in serum levels of interleukin-1β, interferon-γ, soluble interleukin-2 receptors (sIL-2r), and cortisol. However, a significant negative correlation was found between fatigue-related symptoms and sIL-2r levels in the experimental (r = -0.325), but not the control group (r = -0.046). These findings suggest that viral infection can produce prolonged behavioral, emotional and cognitive problems mainly in subjects belonging to the low SES.
Bibliographical noteFunding Information:
We are indebted to Dr P. Ben-Ishai and epidemiological nurses of the Israeli Ministry of Health, for their diligent work in guidance and coordination of the immunization procedures; to Mrs Y. Danilov from the Israeli Ministry of Education; to Dr N. Yirmiya, for her useful suggestions throughout the study; to Ms M. Gorfine for her help in data analysis; to Dr J. Weidenfeld, for his help in analysing cortisol levels; to the educational staff of the participating schools and the other agencies that permitted us access to their pupils and to the study subjects themselves for their cooperation and perseverance. This study was supported by grants from the Volkswagen Foundation, the Milton Rosenbaum Endowment Fund for Research in Psychiatric Sciences, the Hadassah-Hebrew University Medical School Mutual Foundation, and Hadassah Medical Center grant No. 513.007/5.