British Cold Study
The British Cold Study (BCS) was a prospective viral challenge study conducted from 1986-1989 among healthy volunteers ages 18-54 years (mean 33.6; SD 10.6). This study primarily focused on psychological stress and its association with common cold susceptibility. Measures of psychological stress included major stressful life events, perceived stress, and negative affect. However, the study included measures of other variables (administered before viral-exposure) as well, including medical history, common cold history, mental health, extraversion, self-esteem, locus of control, social networks and supports, and white blood cell counts.
Participants were 153 men and 246 women who were residents of Great Britain and who volunteered to participate in trials at the Medical Research Council’s Common Cold Unit (CCU) in Salisbury, England. All were judged to be in good health after clinical and laboratory examination on their arrival at the unit. Participants were reimbursed for their travel expenses and were provided with meals and accommodations during the study. At baseline, participants completed an in-person health evaluation to assess study eligibility (see Human Subjects for information on additional inclusion and exclusion criteria).
After completing baseline psychosocial questionnaires and biological assessments (immune assessments and measurement of cotinine [a biochemical indicator of smoking] in serum) participants were administered nasal drops containing one of 5 respiratory viruses: rhinovirus (RV) type 2 (n=86), RV9 (n=126), RV14 (n=92), respiratory syncytial virus (RSV, n=40), or coronavirus type 229E (n=55). Starting 2 days before viral challenge and continuing through 6 days after challenge, each participant was examined in quarantine daily by a clinician using a standard checklist of respiratory signs and symptoms. Approximately 28 days after challenge, participants’ own physicians collected a second serum sample, which was sent to the CCU for serological testing. The definition of a clinical illness in this study was based on the combination of infection (based on viral shedding and/or 4X increase in antibody titers to the challenge virus) and physician diagnosis based on daily cold symptom protocols.
It is important to emphasize that the BCS used definitions of illness that were similar but not identical to the definitions used in the four Pittsburgh studies (i.e., PCS1, PCS2, PMBC, and PCS3). In common with the other studies, a cold diagnosis required that participants be infected with the challenge virus (with all studies using the same criteria to determine infection) and meet a set of specified illness criteria (see Assessment of Infection and Colds). However, whereas the primary illness criteria used in the four Pittsburgh studies were based on objective measurements (mucus weights and nasal clearance function), the illness criterion used in the BCS was a physician’s diagnosis based on daily physical examinations and clinical interviews. Although some other individual markers of disease were assessed in this study (see Clinical Interview and Observations and Tissue Counts), they did not provide sufficient (equivalent) data to use either the Jackson Criteria or the Objective Criteria for illness used in the other studies.