Activation of the innate immune system is commonly accompanied by a set of behavioural, psychological and physiological changes known as ‘sickness behaviour’. In animals, infection-related sickness symptoms are significantly increased by exposure to psychosocial stress, suggesting that psychological and immune stressors may operate through similar pathways to induce sickness. We used a double-blind, randomised, placebo-controlled design to examine the effect of acute psychological stress on immune and subjective mood responses to typhoid vaccination in 59 men. Volunteers were assigned to one of four experimental conditions in which they were either injected with typhoid vaccine or saline placebo, and then either rested or completed two challenging behavioural tasks. Typhoid vaccine induced a significant rise in participants’ serum levels of interleukin-6 (IL-6) and this response was significantly larger in the stress versus rest conditions. Negative mood increased immediately post-tasks, an effect also more pronounced in the vaccine/stress condition. In the vaccine/stress group, participants with larger IL-6 responses had heightened systolic blood pressure responses to tasks and elevated post-stress salivary levels of the noradrenaline metabolite 3-methoxy-phenyl glycol (MHPG) and cortisol. Our findings suggest that, as seen in animals, psychological and immune stressors may act synergistically to promote inflammation and sickness behaviour in humans.

Evidence suggests that optimism may be protective for health during times of heightened stress, yet the mechanisms involved remain unclear. In a double-blind placebo-controlled study, we recently showed that acute psychological stress and an immune stimulus (Typhim-Vi typhoid vaccine) synergistically increased serum levels of interleukin-6 (IL-6) and negative mood in 59 healthy men. Here we carried out further analysis of this sample to investigate the relationship between dispositional optimism and stress-induced changes in immunity and mood. Volunteers were randomly assigned to one of four experimental conditions in which they received either typhoid vaccine or saline placebo, and then rested or completed two mental tasks. In the stress condition, optimism was inversely related to IL-6 responses, independent of age, BMI, trait CES-D depression and baseline IL-6. This relationship was present across both stress groups (combining vaccine and placebo) and was not present in the vaccine/stress group alone, suggesting that optimism protects against the inflammatory effects of stress rather than vaccine per se. Typhoid vaccine induced a significant increase in participants’ circulating anti-Vi antibody levels. Stress had no effect on antibody responses overall. However, in the vaccine/stress group, there was a strong positive association between optimism and antibody responses, indicating that stress accentuated the antibody response to vaccine in optimists. Across the complete sample, more optimistic individuals had smaller increases in negative mood and less reduction in mental vigour. Together these findings suggest that optimism may promote health, by counteracting stress-induced increases in inflammation and boosting the adjuvant effects of acute stress.

Health literacy is known to affect vulnerable communities such as persons living with HIV/AIDS. The purpose of this review was to provide a current summary of research on the impact of health literacy on the health of persons living with HIV/AIDS and to address future areas of need. Contemporary studies focused on expanding the reach of health literacy in HIV/AIDS to retention in HIV care, use of technology for assessing and intervening to improve health literacy, and health literacy across the globe, for example. A number of studies did not find health literacy to explain health behaviors whereas other studies supported such a relationship. Future issues relevant to health literacy in HIV/AIDS include the aging of the HIV population and associated comorbidities, studies to understand the role of health literacy in specific populations affected by HIV/AIDS, and the continued need to refine the definition and measurement of health literacy.

Background The HIV continuum of care paradigm uses a single viral load test per patient to estimate the prevalence of viral suppression. We compared this single-value approach with approaches that used multiple viral load tests to examine the stability of suppression. Methods The retrospective analysis included HIV patients who had at least 2 viral load tests during a 12-month observation period. We assessed the (1) percent with suppressed viral load (<200 copies/mL) based on a single test during observation, (2) percent with suppressed viral loads on all tests during observation, (3) percent who maintained viral suppression among patients whose first observed viral load was suppressed, and (4) change in viral suppression status comparing first with last measurement occasions. Prevalence ratios compared demographic and clinical subgroups. Results Of 10,942 patients, 78.5% had a suppressed viral load based on a single test, whereas 65.9% were virally suppressed on all tests during observation. Of patients whose first observed viral load was suppressed, 87.5% were suppressed on all subsequent tests in the next 12 months. More patients exhibited improving status (13.3% went from unsuppressed to suppressed) than worsening status (5.6% went from suppressed to unsuppressed). Stable suppression was less likely among women, younger patients, black patients, those recently diagnosed with HIV, and those who missed ≥1 scheduled clinic visits. Conclusions Using single viral load measurements overestimated the percent of HIV patients with stable suppressed viral load by 16% (relative difference). Targeted clinical interventions are needed to increase the percent of patients with stable suppression.

The aim of this study was to examine associations of objectively measured physical activity with daily mood ratings and psychophysiological stress responses. We recruited 40 healthy females (aged 28.7 ± 6.1 yrs) who completed a once-a-day mood rating scale for 7 days, along with a 7-day assessment of physical activity using accelerometers and psychophysiological stress testing. The findings suggest that levels of physical activity as measured using an accelerometer are associated with both depressive symptoms over the past 2 weeks (CES-D) (r = - .33, p = .038) and with daily positive emotional style (r = .49, p = .001). The relationship between physical activity and positive emotional style remained after controlling for age, body mass index, and negative emotional style (t = 3.31, p = .002). Physical activity was not related to any psychophysiological stress responses.