Psychosocial factors and the response to influenza vaccination in older adults

Changes in depressive symptoms and antibody production following influenza vaccination in adolescents and adults

OBJECTIVE

Psychological distress has been associated with dampened antibody production following vaccination. Questions remain, however, about whether psychological distress influences vaccine response uniformly across the lifespan, and whether changes in distress result in changes in antibody production across the same period.

METHODS

Participants (N = 148; Mage = 32.2 years, SD = 19.7, range = 12-80 years) took part in consecutive vaccine studies during the 2017-2018 and 2018-2019 influenza seasons. Each influenza season, they reported on their depressive symptoms, provided blood samples, and received the standard influenza vaccine. Participants then provided a second blood sample one month later. Antibody titers were examined pre- and post-vaccination.

RESULTS

Analyses examined both within-season and across-season effects of depressive symptoms, age, and their interaction on vaccine response. Within-season analyses revealed that age predicted antibody response during both seasons (2017-2018 and 2018-2019). Neither depressive symptoms nor the interaction with age were associated with antibody response to vaccination within either season. Across the two seasons, age significantly moderated the association between change in depressive symptoms and change in antibody production. For people who were 48 or older, increases in depressive symptoms across the two seasons were associated with a less robust response to the vaccine in the second season relative to the first season. For people younger than 48, changes in depressive symptoms were not significantly related to changes in antibody production.

CONCLUSIONS

These findings highlight the important role of mental health for older adults' vaccine response, which could have clinical relevance for protection against disease.

Psychosocial and behavioural predictors of immune response to influenza vaccination: a systematic review and meta-analysis

High variability of influenza vaccine efficacy requires the identification of modulators of immunisation that may be targeted as adjuvants in health psychology interventions. Psychosocial and behavioural variables such as psychological stress, greater negative and lower positive affectivity, poor sleep, loneliness, and lack of social support, have been associated with abnormal immune and inflammatory responses and negative health outcomes, yet their effects in modulating vaccine efficacy are yet to be fully understood. We conducted an updated systematic review of longitudinal and experimental studies examining the effects of such variables in predicting immune response to influenza vaccine. PubMed, Medline, PsycINFO, CINAHL and Scopus were searched up to November 2022. Twenty-five studies met the inclusion criteria for qualitative synthesis and 16 provided data for meta-analysis. Low positive and high negative affect were associated with low antibodies and weak cell-mediated immunity following vaccination in qualitative synthesis. Literature on sleep disturbance, loneliness and social support was limited and yielded inconsistent results. Psychological stress was associated with poorer antibody response in meta-analysis. In conclusion, findings from this review suggest a need for further longitudinal and experimental studies on these factors to support their inclusion as target variables in vaccine adjuvant interventions.

Depressive symptoms predict antibody titers after a second dose of the SARS-CoV-2 BNT162b2 vaccine among hospital workers in Japan

BACKGROUND

Although factors associated with the antibody response to the BNT162b2 mRNA COVID-19 vaccine have been reported, psychological factors have not been examined. Depression or anxiety may affect vaccine reactions because these factors influence immune responses. This study aimed to determine whether psychological status at the time of vaccination predicts antibody responses.

METHODS

A prospective observational study of the BNT162b2 mRNA COVID-19 vaccine response was carried out among individuals attending for an annual health check-up. Participants included 78 volunteers out of 80 hospital workers in Nagoya, Japan. No participants had been infected with COVID-19 and all gave written informed consent to participate in the study. Blood samples were obtained approximately 28 days after the second dose of the vaccine, and antibody titers of the SARS-CoV-2 spike protein were determined using the SARS-CoV-2 IgG II Quant assay. Participants completed the Japanese version of the hospital anxiety and depression scale (HADS) questionnaire, one day before both vaccinations. Participants also recorded any adverse reactions, such as body temperature and other side effects, every day for two weeks after each dose. The relationships between antibody titers and the predictive factors were analyzed using multiple linear regression analysis, with the antibody titers as the dependent variables, followed by univariate analysis.

RESULTS

Multiple linear regression analysis revealed that no or excessive alcohol intake (p = 0.039), poor results from a health check-up (p = 0.011), a longer duration between the second dose and blood collection (p = 0.039), and increased degree of depressive symptoms (p = 0.041) were significant negative predictors of antibody titers, while body temperature one day after the second dose as a significant positive predictor of antibody titers (p < 0.0005).

CONCLUSION

We identified that depressive symptoms just before the second dose of the BNT162b2 mRNA COVID-19 were an independent negative predictor of antibody responses, in addition to other factors. Our results highlight the importance of mental health at the time of vaccination to achieve the higher antibody responses necessary to acquire humoral immunity.

Severe mental disorders and vaccinations - a systematic review

OBJECTIVES

People with severe mental illnesses (SMI: schizophrenia, depressive disorder, bipolar disorder) have a high risk of being infected by viruses and suffer a more severe infection illness course than the general population. The aim of this literature review was to elucidate rates as well as immunogenicity and side effects of vaccinations in SMI.

METHODS

All studies in the English or German language, which investigated either prevalence rates or effects of vaccinations in the target groups, were systematically searched in the databank PubMed by three independent authors using the PRISMA guidelines and discussed in more detail.

RESULTS

The search found 24 studies reporting epidemiological data and 16 investigating immunogenicity of vaccinations. The results on prevalence rates, antibody production, inflammation response and side effects were inconsistent. About interactions with psychotropic medication, only two studies on clozapine were found.

CONCLUSIONS

Only a few trials with heterogeneous samples have investigated prevalence and effects of vaccinations in SMI. Sex, age and other factors such as somatic comorbidities and special vaccination programmes have not been considered continuously and may influence rates as well. As individuals with SMI might be at special risk, further research on the willingness to be vaccinated as well as efficacy of vaccinations is needed.

Social cohesion and loneliness are associated with the antibody response to COVID-19 vaccination

BACKGROUND

Recent research has suggested that psychosocial factors influence the antibody response to vaccine, including SARS-CoV-2 (COVID-19) vaccines. Here we investigated whether social cohesion and loneliness were predictive of antibody response to a single dose of a COVID-19 vaccine. We also tested if the association between social cohesion and antibody response was mediated by feelings of loneliness.

METHODS

Participants (N = 676) COVID-19 antibody data were extracted from March 2021 wave of the Understanding Society COVID-19 study from the UK. Relevant socio-demographics, health and lifestyle, loneliness, social cohesion indices were also used in a series of hierarchical linear regression to test our main hypotheses.

RESULTS

After controlling for covariates (e.g., age and chronic health conditions), lower social cohesion was associated with a lower antibody response. Further, the association between social cohesion and poorer antibody responses was mediated by loneliness; those reporting lower social cohesion also reported higher loneliness, which in turn was associated with lower antibody response.

CONCLUSION

This study confirms that feelings of 'being in it together' relate to the strength of the antibody response to COVID-19 vaccination, emphasising the importance of the social cohesion agenda during the pandemic.

Immune response to vaccination in adults with mental disorders: A systematic review

BACKGROUND

Mental disorders are associated with immune dysregulation as measured by serum levels of biological markers of immunity. Adults with mental disorders have also been reported to have attenuated post vaccine immune response. The COVID-19 pandemic has invited the need to determine whether individuals with mental disorders exhibit differential immune response following the administration of vaccines for other infections.

METHODS

A systematic search of MEDLINE, Embase, Cochrane, and PsycInfo was conducted from inception to May 2021 investigating vaccine response in persons with mental disorders, as measured by biological markers of immunity (i.e., antibodies, cytokines).

RESULTS

Thirteen articles were identified which evaluated vaccine efficacy in persons with mental disorders. Individuals with major depressive disorder (MDD) or schizophrenia revealed attenuated immune response to vaccination, or no statistical difference compared to control subjects. Individuals with anorexia nervosa or post-traumatic stress disorder (PTSD) displayed no attenuated post-vaccination antibody level. Individuals with insomnia displayed lower levels of antibodies after vaccination, whereas individuals with obstructive sleep apnea (OSA) displayed no difference in vaccine response compared to control subjects.

LIMITATIONS

The limitations of this review include the relatively few articles included (n = 13) and small sample sizes (less than thirty subjects) in the majority of articles.

CONCLUSION

Vaccine response in adults with a mental disorder remains inconclusive. Notwithstanding the heterogeneity and relatively small number of studies, available evidence does suggest attenuated immune response across disparate vaccinations. Future research is required to confirm vaccine efficacy in persons with mental disorders, especially regarding immune responses to COVID-19 vaccination.

SARS-CoV-2 Vaccines: clinical endpoints and psychological perspectives: A literature review

Background

About 270 million cases have been confirmed, and 5.3 million fatalities Worldwide due to SARS-CoV-2. Several vaccine candidates have entered phase 3 of the clinical trial and are being investigated to provide immunity to the maximum percentage of people. A safe and effective vaccine is required to tackle the current COVID-19 waves. There have been reports that clinical endpoints and psychological parameters are necessary to consider vaccine efficacy. This review examines the clinical endpoints required for a successful SARS-CoV-2 vaccine and the influences of psychological parameters on its efficacy.

Methods

The main research question was to find out the clinical endpoints that determine the vaccine efficacy? And what kind of psychological parameters affect the vaccine efficacy? The information was taken from several journals, databases, and scientific search engines like Googe scholar, Pubmed, Scopus, Web of Science, Science direct, WHO website, and other various sites. The research studies were searched using keywords; SAR-CoV-2 vaccine efficacy, psychological effect on SARS-CoV-2 vaccine, SARS-CoV-2 vaccine endpoints.

Results

This review has highlighted various clinical endpoints that are the main determinants of clinical vaccine efficacy. Currently, vaccinations are being carried out throughout the world; it is important to investigate the main determinants affecting vaccine efficacy. We have focused on the clinical endpoints and the influence of psychological parameters that affect the vaccine efficacy in clinical settings. The primary endpoints include the risk of infection, symptoms, and severity of COVID-19, while hospitalization length, supplemental oxygen requirement, and mechanical ventilation are secondary endpoints in the clinical endpoints. Some tangential endpoints were also considered, including organ dysfunction, stroke, and MI. Many psychological associated things have influenced the vaccine efficacy, like the lower antibody titers in the vaccinated people. In addition to that, Short- and long-term stress and sleep deprivation were also found to affect the vaccine efficacy.

Conclusion

The review summarizes the important clinical endpoints required for a successful vaccine candidate. In addition to primary and secondary endpoints, auxiliary endpoints and the disease burden also play an important role in modulating vaccine efficacy. Moreover, the psychological perspective also influences vaccine efficacy. Effective follow-up of participants should follow to examine the clinical endpoints to reach any conclusion about vaccine efficacy.

The effect of sex on responses to influenza vaccines

The poor uptake and limited effectiveness of seasonal influenza vaccines mean that influenza continues to create a significant burden of disease. It has been hypothesized that sex differences are present in responses to seasonal influenza vaccines, and that these differences may contribute to this poor vaccine success. This has led to the suggestion that vaccines should be tailored to an individual's biological sex. However, studies in this field are often low quality. Comprehensive analysis of the available literature reveals that there is insufficient evidence to support sex differences in vaccine immunogenicity, effectiveness, or efficacy. Nonetheless, differences in vaccine safety are consistently observed, with females reporting adverse events following immunization more frequently than males. Bias introduced by gender differences in passive reporting of adverse effects may underlie this phenomenon. Highly controlled studies are required in future before any conclusions can be made about potential sex differences in response to seasonal influenza vaccines.

Well-Being and Cooking Behavior: Using the Positive Emotion, Engagement, Relationships, Meaning, and Accomplishment (PERMA) Model as a Theoretical Framework

The prevalence of psychosocial distress is increasing in the United States. At the same time, the American default lifestyle has steadily displaced household food production with industrial food production, despite increased cultural interest in cooking. An important focus of cooking research to date has been on cooking's association with nutrition and dietary quality. Less focus has been placed on how cooking might foster the qualities that allow for mitigation of psychosocial distress and promote well-being. Rooted in its evolutionary role in the human experience, cooking requires skills and knowledge that have the capacity to encourage aspects of well-being as described by Seligman as flourishing. Evidence for a beneficial role of cooking in psychosocial health exists, but the exploration is limited, potentially due to lack of a theoretical context to explain these benefits. From this perspective, we review the current literature showing the application of Seligman's prominent well-being model, Positive emotion, Engagement, Relationships, Meaning, and Accomplishment (PERMA), to cooking, defined as the activity related to the preparation of food or a meal. We propose that the PERMA model as applied to cooking may function as a theoretical framework to explore psychosocial outcomes associated with cooking. Broader application of this approach may also help to further the application of positive psychology in the developing literature around psychosocial health and nutrition-related chronic diseases.

Social Support and Antibody Responses to Vaccination: A Meta-Analysis

BACKGROUND

Social support and social integration have been linked to lower rates of morbidity and mortality. However, the biological mechanisms responsible for such links need greater attention. Vaccine paradigms provide an integrative window into immune system involvement in the protective influence of social support/integration.

PURPOSE

The main aim of this article was to conduct a meta-analytic review of the association between social support/social integration and antibody responses to vaccines. Exploratory analyses also examined effect sizes and confidence intervals as a function of several factors to inform future research.

METHOD

A literature search was conducted using the ancestry approach and with PsycInfo, Medline, and the Psychology and Behavioral Science Collection by crossing the exact keywords of social support or social integration with vaccine or antibodies. The review identified nine studies with a total of 672 participants.

RESULTS

The omnibus meta-analysis showed that social support/social integration was related to higher antibody levels following vaccination, but the average effect size was small and the lower bound of the confidence interval included zero (Zr = 0.06 [-.04, .15]). These results did not appear to differ much as a function of the operationalization of social relationships, participant age, or follow-up period, although effect sizes appeared larger for studies using a primary antigen.

CONCLUSIONS

These data provide some evidence that social support may be linked to antibody responses to vaccines. However, effect sizes are mostly small and zero overall effect cannot be ruled out. Future studies would benefit from larger sample sizes and greater consideration of methodological issues associated with secondary immune responses to antigen.

A systematic review of the impact of psychosocial factors on immunity: Implications for enhancing BCG response against tuberculosis

BACKGROUND

Tuberculosis (TB) remains an urgent global public health priority, causing 1.5 million deaths worldwide in 2018. There is evidence that psychosocial factors modulate immune function; however, how this may influence TB risk or BCG vaccine response, and whether this pathway can be modified through social protection, has not been investigated. This paper aims to: a) systematically review evidence of how psychosocial factors influence the expression of biomarkers of immunity, and b) apply this general evidence to propose plausible TB-specific pathways for future study.

METHODS

Papers reporting on the impact of psychosocial stressors on immune biomarkers in relation to infectious disease risk were identified through a search of the databases MEDLINE, PsycINFO, Global Health and PsycEXTRA alongside reference list and citation searching of key papers. Data extraction and critical appraisal were carried out using a standardised form. The findings were tabulated and synthesised narratively by infectious disease category, and used to propose plausible mechanisms for how psychosocial exposures might influence immune outcomes relevant to TB and BCG response.

RESULTS

27,026 citations were identified, of which 51 met the inclusion criteria. The literature provides evidence of a relationship between psychosocial factors and immune biomarkers. While the direction and strength of associations is heterogenous, some overarching patterns emerged: adverse psychosocial factors (e.g. stress) were generally associated with compromised vaccine response and higher antibody titres to herpesviruses, and vice versa for positive psychosocial factors (e.g. social support).

CONCLUSIONS

The evidence identifies pathways linking psychosocial factors and immune response: co-viral infection and immune suppression, both of which are potentially relevant to TB and BCG response. However, the heterogeneity in the strength and nature of the impact of psychosocial factors on immune function, and lack of research on the implications of this relationship for TB, underscore the need for TB-specific research.

Is there a difference in the immune response, efficacy, effectiveness and safety of seasonal influenza vaccine in males and females? - A systematic review

INTRODUCTION

Seasonal influenza is an important cause of morbidity and mortality, despite being vaccine-preventable. Sex factors (genes and hormones) seem to impact individuals' susceptibility to infectious diseases and their response to vaccination. However, most vaccine studies do not explicitly assess sex differences in vaccine response, but rather adjust for sex.

METHODS

We conducted a systematic review to analyze immunogenicity, efficacy, effectiveness and/or safety of seasonal influenza vaccine data stratified by sex. We searched PubMed, EMBASE, CINAHL, Web of Science and clinicaltrials.gov for observational studies and phase III/IV trials from January 1990 to June 2018, published in English or French. Two reviewers independently screened all references, then proceeded to data extraction and quality assessment using the Cochrane tools (RoB and ROBINS-I) on included studies.

RESULTS

Of the 5,745 citations retrieved, 46 studies were included in the SR. Overall, 18 studies assessed immunogenicity, 1 estimated efficacy, 6 measured effectiveness and 25 evaluated safety of seasonal influenza vaccine in females and males (four studies reported on two sex-stratified outcomes concomitantly).

CONCLUSION

No clear conclusion could be drawn regarding the effect of sex on the immunogenicity and effectiveness of seasonal influenza vaccine, but higher rates of adverse events following immunization (AEFIs) were reported in females. The heterogeneity of data and studies' low quality prevented us from conducting a meta-analysis. There is a need to emphasize on the appropriate use of the terms sex and gender in biomedical research. Evidence of higher quality is needed to better understand sex differences in response to influenza vaccine.

Factors That Influence the Immune Response to Vaccination

There is substantial variation between individuals in the immune response to vaccination. In this review, we provide an overview of the plethora of studies that have investigated factors that influence humoral and cellular vaccine responses in humans. These include intrinsic host factors (such as age, sex, genetics, and comorbidities), perinatal factors (such as gestational age, birth weight, feeding method, and maternal factors), and extrinsic factors (such as preexisting immunity, microbiota, infections, and antibiotics). Further, environmental factors (such as geographic location, season, family size, and toxins), behavioral factors (such as smoking, alcohol consumption, exercise, and sleep), and nutritional factors (such as body mass index, micronutrients, and enteropathy) also influence how individuals respond to vaccines. Moreover, vaccine factors (such as vaccine type, product, adjuvant, and dose) and administration factors (schedule, site, route, time of vaccination, and coadministered vaccines and other drugs) are also important. An understanding of all these factors and their impacts in the design of vaccine studies and decisions on vaccination schedules offers ways to improve vaccine immunogenicity and efficacy.

The Vaccination Model in Psychoneuroimmunology Research: A Review

This chapter explores the reasoning behind using the vaccination model to examine the influence of psychosocial factors on immunity. It then briefly discusses the mechanics of the vaccination response and the protocols used in psychoneuroimmunology vaccine research, before giving examples from the research literature of the studies examining relationships such as the association between stress and vaccination response. It also explores the ways the vaccination model can be used to answer key questions in psychoneuroimmunology, such as the following: "Does it matter when stressful life events occur relative to when the vaccine is received?" "What are the effects of prior exposure to the antigen?" "Do other psychosocial factors influence vaccine response besides stress?" Finally, it briefly considers the mechanisms underlying psychosocial factors and vaccination response associations and the future research needed to understand these better, and indeed to use current and future knowledge to improve and enhance vaccine responses in key at-risk populations.

Is Insomnia a Risk Factor for Decreased Influenza Vaccine Response?

Healthy young adult college students (N = 133) with Insomnia (n = 65) or No Insomnia (n = 68) were compared on influenza serum antibody levels pre- and four weeks postvaccination. Volunteers underwent structured clinical interviews for sleep disorders to ensure insomnia diagnoses, as well as psychiatric interviews, physical examinations, and drug testing to ensure comorbid health problems were not potential confounds. There were significant time (both groups had increases in antibody levels pre- to postvaccination) and group (Insomnia group had lower HI antibody levels overall) main effects, but the time × group interaction was nonsignificant. Exploratory analyses did find significant PSQI x Time (p < .001) and Insomnia Status × Time (p = .002) interaction effects. Results indicate insomnia may be a risk factor for lowered immunity to the influenza virus.

Depressive symptoms and immune response to meningococcal conjugate vaccine in early adolescence

Research findings in psychoneuroimmunology document reliable, bidirectional linkages among psychological processes, the nervous system, and the immune system. However, available data are based almost entirely on animal and adult human studies; the application to children and adolescents is uncertain. We capitalized on the experimental leverage provided by a routine vaccination to examine the link between mood symptoms and the immune response to a vaccine challenge in early adolescence. One hundred twenty-six 11-year-olds for whom vaccine response data were available were assessed at prevaccination and 4 weeks, 3 months, and 6 months following vaccination; self-report ratings of depression and anxiety as well as measures of psychosocial and somatic risk were assessed prior to vaccine response. Analyses indicated that children's internalizing mood symptoms were associated with elevated and persistently higher antibody responses, with evidence extending to two of the four serogroups. The associations remained after controlling for multiple possible confounders (social class, body mass index, sleep, psychosocial risk, and pubertal status). The observed enhanced vaccine response associated with depressive and anxious symptoms in early adolescence may reflect an important developmental difference in immune system-brain interplay between adults and children, and it underscores the need for further developmental studies of psychoneuroimmunology.

Psychological stress and reproductive aging among pre-menopausal women

BACKGROUND

Life history models suggest that biological preparation for current versus longer term reproduction is favored in environments of adversity. In this context, we present a model of reproductive aging in which environmental adversity is proposed to increase the number of growing follicles at the cost of hastening the depletion of the ovarian reserve over time. We evaluated this model by examining psychological stress in relation to reproductive aging indexed by antral follicle count (AFC), a marker of total ovarian reserve. We hypothesized that stress would be related to (i) higher AFC in younger women, reflecting greater reproductive readiness as well as (ii) greater AFC loss across women, reflecting more accelerated reproductive aging.

METHODS

In a multi-ethnic, community sample of 979 participants [ages 25-45 (mean (standard deviation) = 35.2 (5.5)); 27.5% Caucasian] in the Ovarian Aging study, an investigation of the correlates of reproductive aging, the interaction of age-x-stress was assessed in relation to AFC to determine whether AFC and AFC loss varied across women experiencing differing levels of stress. Stress was assessed by the perceived stress scale and AFC was assessed by summing the total number of antral follicles visible by transvaginal ultrasound.

RESULTS

In linear regression examining AFC as the dependent variable, covariates (race/ethnicity, socio-economic status, menarcheal age, hormone-containing medication for birth control, parity, cigarette smoking, bodymass index, waist-to-hip ratio) and age were entered on step 1, stress on step 2 and the interaction term (age-x-stress) on step 3. On step 3, significant main effects showed that older age was related to lower AFC (b = -0.882, P = 0.000) and greater stress was related to higher AFC (b = 0.545, P = 0.005). Follow-up analyses showed that the main effect of stress on AFC was present in the younger women only. A significant interaction term (b = -0.036, P = 0.031) showed the relationship between age and AFC varied as function of stress. When the sample was divided into tertiles of stress, the average follicle loss was -0.781, -0.842 and -0.994 follicles/year in the low-, mid- and high-stress groups, respectively.

CONCLUSIONS

Psychological stress was related to higher AFC among younger women and greater AFC decline across women, suggesting that greater stress may enhance reproductive readiness in the short term at the cost of accelerating reproductive aging in the long term. Findings are preliminary, however, due to the cross-sectional nature of the current study.

Vulnerability, distress, and immune response to vaccination in older adults

Psychological distress and biobehavioral vulnerability (e.g., arising from being older or sedentary) have independently predicted immune responses to influenza vaccination in older adults. Recent research examining basal inflammatory markers suggests that, rather than having additive effects, distress and vulnerability interact with each other. The present study tested the interactions between distress and age, sex, education, BMI, sleep quality, and physical activity over up to 8 years in older adults (N=134; M age=74 years) who received annual influenza vaccinations. Measured vaccination responses were changes from baseline in antibody to the three vaccine components, interleukin (IL)-6, and β2-microglobulin. As predicted, the most robust effects were interactions between distress and vulnerability. BMI interacted with stable individual differences in distress to predict antibody response (t(132)=3.09, p<0.003), such that only the combination of low BMI and low distress was associated with a more robust antibody response. Likewise, changes in physical activity over time interacted with changes in distress (t(156)=2.96, p<0.004), such that only the combination of increased physical activity and decreased distress was associated with a more robust antibody response. Finally, there was a smaller tendency for age to interact with stable individual differences in distress (t(130)=2.46, p<0.015), such that distress was more strongly associated with post-vaccination IL-6 at older ages. The synergistic effects of distress and other forms of vulnerability are an important direction for future research and a target for interventions to improve immunological health in older adults.

The vaccination model in psychoneuroimmunology research: a review

This chapter explores the reasoning behind using the vaccination model to examine the influence of psychosocial factors on immunity. It then briefly discusses the mechanics of the vaccination response and the protocols used in Psychoneuroimmunology vaccine research, before giving examples from the research literature of the studies examining relationships such as the association between stress and the vaccination response. It also explores the ways the vaccination model can be used to answer key questions in Psychoneuroimmunology, such as: "does it matter when stressful life events occur relative to when the vaccine is received?" "what are the effects of prior exposure to the antigen?" and "do other psychosocial factors influence vaccine response besides stress?" Finally, it briefly considers the mechanisms underlying psychosocial factors and vaccination response associations and the future research needed to understand these better, and indeed to use current and future knowledge to improve and enhance vaccine responses in key at risk populations.

Social relationships and mortality risk: a meta-analytic review

BACKGROUND

The quality and quantity of individuals' social relationships has been linked not only to mental health but also to both morbidity and mortality.

OBJECTIVES

This meta-analytic review was conducted to determine the extent to which social relationships influence risk for mortality, which aspects of social relationships are most highly predictive, and which factors may moderate the risk.

DATA EXTRACTION

Data were extracted on several participant characteristics, including cause of mortality, initial health status, and pre-existing health conditions, as well as on study characteristics, including length of follow-up and type of assessment of social relationships.

RESULTS

Across 148 studies (308,849 participants), the random effects weighted average effect size was OR = 1.50 (95% CI 1.42 to 1.59), indicating a 50% increased likelihood of survival for participants with stronger social relationships. This finding remained consistent across age, sex, initial health status, cause of death, and follow-up period. Significant differences were found across the type of social measurement evaluated (p<0.001); the association was strongest for complex measures of social integration (OR = 1.91; 95% CI 1.63 to 2.23) and lowest for binary indicators of residential status (living alone versus with others) (OR = 1.19; 95% CI 0.99 to 1.44).

CONCLUSIONS

The influence of social relationships on risk for mortality is comparable with well-established risk factors for mortality. Please see later in the article for the Editors' Summary.

Cardiovascular exercise training extends influenza vaccine seroprotection in sedentary older adults: the immune function intervention trial

OBJECTIVES

To determine whether cardiovascular exercise training resulted in improved antibody responses to influenza vaccination in sedentary elderly people who exhibited poor vaccine responses.

DESIGN

Single-site randomized parallel-arm 10-month controlled trial.

SETTING

University of Illinois at Urbana-Champaign.

PARTICIPANTS

One hundred forty-four sedentary, healthy older (69.9 +/- 0.4) adults.

INTERVENTIONS

Moderate (60-70% maximal oxygen uptake) cardiovascular exercise was compared with flexibility and balance training.

MEASUREMENTS

The primary outcome was influenza vaccine response, as measured according to hemagglutination inhibition (HI) anti-influenza antibody titer and seroprotective responses (HI titer > or =40). Secondary measures included cardiovascular fitness and body composition.

RESULTS

Of the 160 participants enrolled, 144 (90%) completed the 10-month intervention with excellent compliance ( approximately 83%). Cardiovascular, but not flexibility, exercise intervention resulted in improvements in indices of cardiovascular fitness, including maximal oxygen uptake. Although not affecting peak (e.g., 3 and 6 weeks) postvaccine anti-influenza HI titers, cardiovascular exercise resulted in a significant increase in seroprotection 24 weeks after vaccination (30-100% dependent on vaccine variant), whereas flexibility training did not.

CONCLUSION

Participants randomized to cardiovascular exercise experienced improvements in influenza seroprotection throughout the entire influenza season, whereas those in the balance and flexibility intervention did not. Although there were no differences in reported respiratory tract infections, the exercise group exhibited reduced overall illness severity and sleep disturbance. These data support the hypothesis that regular endurance exercise improves influenza vaccine responses.

Psychological stress and antibody response to influenza vaccination: a meta-analysis

Vaccination is an important public health strategy for reducing the risk of influenza at the societal level. However, at the individual level, not everyone is protected by vaccination, and increases in antibody titers may fail to reach protective levels. Several recent studies suggest that psychological stress may contribute to these individual differences. Exploring this hypothesis, we conducted a meta-analysis of 13 studies examining the influence of psychological stress on antibody responses following influenza vaccination. The studies were identified through systematic searches in MEDLINE and PsychINFO and included a total of 1158 men and women. In five studies, the increased antibody levels of caregivers following vaccination were compared to those of non-caregivers. The remaining studies focused on associations between self-reported stressful life events or perceived stress and increased antibody titers following vaccination. The meta-analysis revealed a significant negative association between psychological stress and antibody responses to influenza vaccination. While effect sizes were similar across different indicators of stress, antibody responses to the A/H1N1 and B-influenza types appeared to be more sensitive to stress than the A/H3N2 type. It was investigated whether the association between stress and antibody response differed between young and elderly, and the results revealed significant negative associations between stress and peak antibody titers in both age groups. These findings suggest the importance of additional research to explore responsible mechanisms and possible contributions of stress to the public health problem of inadequate responses to vaccination.

Review: Brain—immune communication psychoneuroimmunology of multiple sclerosis

The central nervous system (CNS) and the immune system are two extremely complex and highly adaptive systems. In the face of a real or anticipated threat, be it physical (eg, infection) or psychological (eg, psychosocial stress) in nature, the two systems act in concert to provide optimal adaptation to the demanding internal or environmental conditions. During instances of well being, the communication between these two systems is well tuned and balanced. However, a disturbed crosstalk between the CNS and the immune system is thought to play a major role in a wide series of disorders characterized by a hyporesponsive or hyperresponsive immune system. In multiple sclerosis (MS), a chronic inflammatory and neurodegenerative disease, an excess of inflammatory processes seems to be a hallmark and there is growing evidence for a disturbed communication between the CNS and the immune system as a crucial pathogenic factor. While the exact mechanisms for these phenomena are still poorly understood, the young discipline of psychoneuroimmunology (PNI), which focuses on the mechanism underlying the brain to immune crosstalk, might offer some insights into the existing pathogenic mechanisms. Findings from the field of PNI might also help to gain a better understanding regarding the origin and course of MS clinical symptoms such as fatigue and depression.

Social Support and Health: A Review of Physiological Processes Potentially Underlying Links to Disease Outcomes

Social support has been reliably related to lower rates of morbidity and mortality. An important issue concerns the physiological mechanisms by which support influences such health endpoints. In this review, I examine evidence linking social support to changes in cardiovascular, neuroendocrine, and immune function. Consistent with epidemiological evidence, social support appears to be related to more positive "biological profiles" across these disease-relevant systems. Recent research on immune-mediated inflammatory processes is also starting to provide data on more integrative physiological mechanisms potentially linking social support to health. The implications of these links, along with future research directions are discussed.

Bereavement and marriage are associated with antibody response to influenza vaccination in the elderly

Stressful life events exposure including bereavement, an event commonly experienced by elderly people, social support, marital status, and satisfaction were examined in relation to antibody response to the annual trivalent influenza vaccination in an elderly community sample (N=184). Antibody response was assessed at baseline, and at 1 and 12 months following vaccination. Taking into account baseline antibody titer, overall life events exposure and social support were not associated with response to any of the influenza strains. However, bereavement in the year prior to vaccination was negatively associated with the 1-month response to the A/Panama and B/Shangdong strains. Being married and having higher marital satisfaction was also associated with higher peak responses to the A/Panama influenza strain at 1 month. The positive association between marital satisfaction and A/Panama response was particularly evident in the younger half of the married sample. These associations largely withstood adjustment for potential confounders. Thus, in the elderly, peak antibody response was associated with bereavement and marriage, and not the more general factors, life events and social support, related to antibody response in student samples. This suggests the importance of taking a life course approach to examining relationships between psychosocial factors and immunity, and that interventions to modify the impact of these factors should address those most salient for each age group.

Norman Cousins Lecture. The uses and abuses of psychoneuroimmunology: a global overview

Studies of interactions between the nervous and immune systems that effect immunological and behavioral changes are relevant to our understanding biological issues pertinent to evolution, ethology, ecology, and aging, in addition to our understanding the immune and nervous systems per se. Psychoneuroimmunology also relates to homeland security, science education, and the practice of conventional as well as complementary and alternative medicine. This paper will highlight just some of these global implications of psychoneuroimmunology.