Vulnerability, distress, and immune response to 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.

Vaccine-preventable hospitalisations in adult mental health service users: a population study

BACKGROUND

Vaccine-preventable conditions cause preventable illness and may increase mortality in people living with mental illness. We examined how risks of hospitalisation for a wide range of vaccine-preventable conditions varied by age and sex among mental health (MH) service users.

METHODS

Linked population data from New South Wales (NSW), Australia were used to identify vaccine-preventable hospitalisations (VPH) for 19 conditions from 2015 to 2020. Adult MH service users (n = 418 915) were compared to other NSW residents using incidence rates standardised for age, sex and socioeconomic status. Secondary analyses examined admissions for COVID-19 to September 2021.

RESULTS

We identified 94 180 VPH of which 41% were influenza, 33% hepatitis B and 10% herpes zoster. MH service users had more VPH admissions [adjusted incidence rate ratio (aIRR) 3.2, 95% CI 3.1-3.3]. Relative risks were highest for hepatitis (aIRR 4.4, 95% CI 4.3-4.6), but elevated for all conditions including COVID-19 (aIRR 2.0, 95% CI 1.9-2.2). MH service users had a mean age of 9 years younger than other NSW residents at first VPH admission, with the largest age gap for vaccine-preventable pneumonias (11-13 years younger). The highest relative risk of VPH was among MH service users aged 45-65.

CONCLUSIONS

MH service users have increased risk of hospitalisation for many vaccine-preventable conditions. This may be due to reduced vaccination rates, more severe illness requiring hospitalisation, greater exposure to infectious conditions or other factors. People living with mental illness should be prioritised in vaccination strategies.

The nutrition and immunity (nutrIMM) study: protocol for a non-randomized, four-arm parallel-group, controlled feeding trial investigating immune function in obesity and type 2 diabetes

Introduction

Individuals with obesity and/or type 2 diabetes are at higher risk of infection and have worse prognoses compared to healthy individuals. Several factors may influence immune responses in this population, including high adiposity, hyperglycemia, and unhealthy dietary habits. However, there is insufficient data on the independent or clustered contribution of these factors to obesity-related immune dysfunction, especially accounting for dietary intake. This study aims to establish the independent contribution of obesity and hyperglycemia to immune dysfunction independent of diet in adults with and without obesity with or without type 2 diabetes.

Methods

The Nutrition and Immunity (nutrIMM) study is a single-centre, non-randomized, four-arm, parallel-group, controlled feeding trial. It will enroll adults without obesity (Lean-NG) and with obesity and three metabolic phenotypes of normoglycemia, glucose intolerance, and type 2 diabetes. Participants will be assigned to one of four groups and will consume a standard North American-type diet for 4 weeks. The primary outcomes are plasma concentration of C-reactive protein and concentration of ex-vivo interleukin-2 secreted upon stimulation of T cells with phytohemagglutinin.

Discussion

This will be the first controlled feeding study examining the contribution of obesity, hyperglycemia, and diet on systemic inflammation, immune cell phenotype, and function in adults of both sexes. Results of this clinical trial can ultimately be used to develop personalized dietary strategies to optimize immune function in individuals with obesity with different immune and metabolic profiles.

Clinical trial registration

ClinicalTrials.gov, identifier NCT04291391.

The roles of inflammation, affect, and interoception in predicting social perception

"Sickness behavior" is an orchestrated suite of symptoms that commonly occur in the context of inflammation, and is characterized by changes in affect, social experience, and behavior. However, recent evidence suggests that inflammation may not always produce the same set of sickness behavior (e.g., fatigue, anhedonia, and social withdrawal). Rather, inflammation may be linked with different behavior across contexts and/or across individuals, though research in this area is under-developed to-date. In the present study (n = 30), we evaluated the influence of affective context and individual differences in difficulty detecting bodily sensations (i.e., interoceptive difficulty) on social perception following an inflammatory challenge. Inflammation was induced using the influenza vaccine and inflammatory reactivity was operationalized as changes in circulating levels of interleukin-6 (IL-6) before the vaccine and approximately 24 h later. Twenty-four hours after administration of the influenza vaccine, we manipulated affective context using a well-validated affect misattribution task in which participants made trustworthiness judgments of individuals with neutral facial expressions following the rapid presentation of "prime" images that were positive or negative in affective content. Interoceptive difficulty was measured at baseline using a validated self-report measure. Results revealed significant interactions between inflammatory reactivity to the influenza vaccine and affective context on social perception. Specifically, individuals with greater inflammatory reactivity were more biased by affective context when judging the trustworthiness of neutral faces. In addition, interoceptive difficulty and affective context interacted to predict social perception such that individuals with greater interoceptive difficulty were more biased by affective context in these judgments. In sum, we provide some of the first evidence that inflammation may amplify the saliency of affective cues during social decision making. Our findings also replicate prior work linking interoceptive ability to the use of affect-as-information during social perception, but in the novel context of inflammation.

Health behaviors are largely not predictive of adverse events following influenza vaccination

BACKGROUND

Identifying health behaviors associated with adverse events following immunization (AEFI) could identify intervention targets for AEFI prevention.

METHODS

University employees receiving an influenza vaccination (n = 1301) completed a series of online surveys for health behaviors including sleep, exercise, dietary intake, and smoking habits, and emotional state (baseline), and for indications of AEFI (three days post-vaccination) and influenza-like illness (ILI) symptoms (fortnightly follow-up for 4 months).

RESULTS

29.9% of participants reported an AEFI and 46.0% reported experiencing ILI during follow-up. Multivariate logistic regression revealed usual sleep duration was associated with AEFI (odds ratio 1.20, 95% confidence interval 1.03-1.41), increasing with each hour of sleep. ILI was associated with reporting AEFI (1.70, 1.24-2.33), increasing BMI (1.03, 1.00-1.06) and survey response frequency (1.13, 1.04-1.22), and decreased with better usual sleep quality (0.96, 0.92-1.00) and with increasing age (0.98, 0.96-1.00). Sex stratification revealed no significant predictors of AEFI for either sex; in women, experiencing AEFI increased likelihood of ILI (1.88, 1.25-2.85) and in men, survey completion frequency increased ILI likelihood (1.19, 1.05-1.36).

CONCLUSIONS

Our study suggests modifying health behaviors would not alter AEFI risk and reactogenicity may signal weaker immunogenicity but confirmation through objective measures is warranted.

The Relationship between Mental Disorders and the COVID-19 Pandemic—Course, Risk Factors, and Potential Consequences

In this review the authors discuss that COVID-19 has already had a direct impact on the physical health of many people and that it appears to have put at risk the mental health of large populations. In this review, we also discuss the relationship between mental disorders and the SARS-CoV-2 infection. We convey the disorders’ risk factors and the more serious mental disorder consequences of COVID-19. People with mental health disorders could be more susceptible to the emotional responses brought on by the COVID-19 epidemic. The COVID-19 pandemic may adversely influence the mental health of patients with already diagnosed mental disorders. For the aim of dealing better with the psychological problems of people afflicted by the COVID-19 pandemic, new psychological procedures are required.

Body Mass Index and Antibody Persistence after Measles, Mumps, Rubella and Hepatitis B Vaccinations

Overweight and obesity may cause a reduced response to vaccination. The purpose of the present research was to study the relationship between current body mass index (BMI) and antibody persistence after vaccination against measles, mumps, and rubella (MMR) and hepatitis B virus (HBV) given during childhood, as per the current vaccination schedule. The study was conducted on 2185 students at the School of Medicine, University of Padua, Italy. The mean age of the participants was 20.3 years. After adjusting for sex, age at first dose of vaccine administered, age at last dose, and age at study enrollment, no significant association was found between lack of serologic protection and BMI for either the HBV vaccine or each component of the MMR vaccine. For the first time, the absence of this relationship was demonstrated for the MMR vaccine. Given the evidence currently available, further research on BMI and vaccines in general remains desirable.

Effects of Exercise and Physical Activity Levels on Vaccination Efficacy: A Systematic Review and Meta-Analysis

Objective: We examined whether different intensities of exercise and/or physical activity (PA) levels affected and/or associated with vaccination efficacy. Methods: A systematic review and meta-analysis was conducted and registered with PROSPERO (CRD42021230108). The PubMed, EMBASE, Cochrane Library (trials), SportDiscus, and CINAHL databases were searched up to January 2022. Results: In total, 38 eligible studies were included. Chronic exercise increased influenza antibodies (standardized mean difference (SMD) = 0.49, confidence interval (CI) = 0.25−0.73, Z = 3.95, I2 = 90%, p < 0.01), which was mainly driven by aerobic exercise (SMD = 0.39, CI = 0.19−0.58, Z = 3.96, I2 = 77%, p < 0.01) as opposed to combined (aerobic + resistance; p = 0.07) or other exercise types (i.e., taiji and qigong, unspecified; p > 0.05). PA levels positively affected antibodies in response to influenza vaccination (SMD = 0.18, CI = 0.02−0.34, Z = 2.21, I2 = 76%, p = 0.03), which was mainly driven by high PA levels compared to moderate PA levels (Chi2 = 10.35, I2 = 90.3%, p < 0.01). Physically active individuals developed influenza antibodies in response to vaccination in >4 weeks (SMD = 0.64, CI = 0.30−0.98, Z = 3.72, I2 = 83%, p < 0.01) as opposed to <4 weeks (p > 0.05; Chi2 = 13.40, I2 = 92.5%, p < 0.01) post vaccination. Conclusion: Chronic aerobic exercise or high PA levels increased influenza antibodies in humans more than vaccinated individuals with no participation in exercise/PA. The evidence regarding the effects of exercise/PA levels on antibodies in response to vaccines other than influenza is extremely limited.

Emotional Distress, Targeted Rejection, and Antibody Production After Influenza Vaccination in Adolescence

OBJECTIVE

The purpose of this study was to explore how both ongoing emotional distress and the experience of a targeted rejection over the past 6 months are associated with adolescents' antibody response to influenza virus vaccination. We predicted that experiencing a targeted rejection would amplify the hypothesized negative association between emotional distress and antibody response after vaccination.

METHODS

Adolescent participants (N = 148) completed two study visits (mean [standard deviation] days between visits = 27.4 [1.8]). At the first visit, they provided blood samples, were administered the seasonal (2018-2019) quadrivalent influenza vaccine (Fluzone, Sanofi Pasteur), completed questionnaires, and participated in a semistructured interview. At the second visit, they provided another blood sample. Hemagglutination-inhibition assays were conducted to determine prevaccination and postvaccination antibody titers. Targeted rejection experiences were coded from adolescents' interviews.

RESULTS

The emotional distress by targeted rejection interaction predicted antibody response to the two A strains and the composite of all vaccine strains (b values = -0.451 to -0.843, p values < .05), but not the two B strains. Results suggested that, among adolescents who experienced a targeted rejection over the past 6 months, emotional distress was negatively associated with vaccine response (however, this finding did not reach statistical significance). Conversely, among adolescents who did not experience a targeted rejection, emotional distress was positively associated with vaccine response (b = 0.173, p = .032).

CONCLUSIONS

The current study highlights the importance of evaluating both acute life events and ongoing distress as they relate to adaptive immune functioning in adolescence.

Inflammatory reactivity to the influenza vaccine is associated with changes in automatic social behavior

Recent evidence suggests differential patterns of social behavior following an inflammatory challenge, such that increases in inflammation may not uniformly lead to social withdrawal. Indeed, increases in inflammation have been associated with enhanced self-reported motivation to approach a specific close other, and greater neural sensitivity to positive social cues. However, no known studies have examined the association between inflammation in response to an inflammatory challenge and social behavior in humans, nor has past research examined specifically how approach and withdrawal behavior may differ based on whether the target is a close other or stranger. To address this, 31 participants (ages 18-24) received the influenza vaccine to elicit a low-grade inflammatory response. The morning before and approximately 24 h after the vaccine, participants provided a blood sample and completed a computer task assessing automatic (implicit) approach and withdrawal behavior toward a social support figure and strangers. Greater increases in the inflammatory cytokine interleukin-6 (IL-6) in response to the vaccine were associated with an increase in accuracy in avoiding strangers and a decrease in accuracy in approaching them. Increases in IL-6 were also associated with a decrease in reaction time to approach a support figure, but only when controlling for baseline IL-6 levels. There were no associations between change in IL-6 and changes in self-reported motivation to engage in social behavior with either close others, or strangers. Together, these findings reveal that increases in inflammation following the influenza vaccine are associated with automatic social behavior, especially behavior suggesting avoidance of unfamiliar social targets and ease in approaching a support figure. These data add to the growing literature suggesting that the association between inflammation and social behavior includes both social withdrawal and social approach, depending on the specific target.

COVID-19 vaccination for people with severe mental illness: why, what, and how?

Psychiatric disorders, and especially severe mental illness, are associated with an increased risk of severe acute respiratory syndrome coronavirus 2 infection and COVID-19-related morbidity and mortality. People with severe mental illness should therefore be prioritised in vaccine allocation strategies. Here, we discuss the risk for worse COVID-19 outcomes in this vulnerable group, the effect of severe mental illness and psychotropic medications on vaccination response, the attitudes of people with severe mental illness towards vaccination, and, the potential barriers to, and possible solutions for, an efficient vaccination programme in this population.

Psychological and Behavioral Predictors of Vaccine Efficacy: Considerations for COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine candidates are being evaluated, with the goal of conferring immunity on the highest percentage of people who receive the vaccine as possible. It is noteworthy that vaccine efficacy depends not only on the vaccine but also on characteristics of the vaccinated. Over the past 30 years, a series of studies has documented the impact of psychological factors on the immune system's vaccine response. Robust evidence has demonstrated that stress, depression, loneliness, and poor health behaviors can impair the immune system's response to vaccines, and this effect may be greatest in vulnerable groups such as the elderly. Psychological factors are also implicated in the prevalence and severity of vaccine-related side effects. These findings have generalized across many vaccine types and therefore may be relevant to the SARS-CoV-2 vaccine. In this review, we discuss these psychological and behavioral risk factors for poor vaccine responses, their relevance to the COVID-19 pandemic, as well as targeted psychological and behavioral interventions to boost vaccine efficacy and reduce side effects. Recent data suggest these psychological and behavioral risk factors are highly prevalent during the COVID-19 pandemic, but intervention research suggests that psychological and behavioral interventions can increase vaccine efficacy.

COVID-19, mental health and psychological first aid

Crises such as the global pandemic of COVID-19 (coronavirus) elicit a range of responses from individuals and societies adversely affecting physical and emotional well-being. This article provides an overview of factors elicited in response to COVID-19 and their impact on immunity, physical health, mental health and well-being. Certain groups, such as individuals with mental illness, are especially vulnerable, so it is important to maximise the supports available to this population and their families during the pandemic. More broadly, the World Health Organization recommends 'Psychological First Aid' as a useful technique that can help many people in a time of crisis.

Early life stress sensitizes individuals to the psychological correlates of mild fluctuations in inflammation

BACKGROUND

Early life stress (ELS) has been linked to health disparities across the human lifespan, particularly increased risk for depression and its recurrence. In this study we explore two plausible and competing pathways through which ELS may lead to depression via inflammation.

METHODS

Participants (ages 18-22; n = 41) completed the Early Trauma Inventory as a measure of ELS. Participants then completed consecutive daily diaries of mood and other sickness behavior for the 7 days prior to and 7 days after receiving the annual influenza vaccine. Circulating concentrations of plasma interleukin-6 (IL-6) were measured immediately before and 24 hr after vaccination.

RESULTS

ELS was not associated with the magnitude of change in IL-6 from pre- to post-vaccine, however, exposure to ELS moderated the association between change in IL-6 from pre- to post-vaccine and changes in both cognitive difficulty and depressed mood. Individuals exposed to greater ELS showed greater psychological sensitivity to increases in IL-6.

CONCLUSIONS

Exposure to ELS may increase sensitivity to peripheral inflammation in the central nervous system. Future studies elaborating on the impact of ELS on the sensitivity of specific neural circuits and cells to inflammation are needed.

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.

Acute exercise decreases vaccine reactions following influenza vaccination among older adults

Although valuable and effective in decreasing disease burden, influenza vaccination has low rates of efficacy, especially in those at most risk. Studies have shown that acute exercise can improve vaccine responses, most consistently with weaker antigens. Here we examined the effect of resistance exercise on the acute and longer-term responses to influenza vaccination among healthy older adults. Forty-six participants (47.8% male, mean 73.4 ± 6.6 years) were randomised to perform one 45-min moderate-intensity resistance exercise session or sit quietly prior to the receipt of influenza vaccination. Acute exercise reduced vaccine reactions but had no effect on either antibody responses or development of influenza-like symptoms during six months of follow-up. Psychosocial and behavioural characteristics were examined for potential associations with the responses to vaccination. Participants (n = 36) vaccinated in the previous year had higher baseline antibody titres but not follow-up titres nor more frequent experience of influenza-like symptoms over 6 months compared to those unvaccinated in the previous year. These findings provide further support for the ability of acute exercise to reduce vaccine reactions and suggest risk factors for vaccine responses for future exploration.

Longitudinal Associations Among Older Adults' Neurocognitive Performance, Psychological Distress, and Self-Reported Cognitive Function

Subjective cognitive complaints increase with age. Although subjective cognitive difficulties have been linked to cognitive impairment and psychological distress, some studies have failed to establish a link between subjective cognitive complaints and present or future cognitive impairment. The present study examined the interactive, longitudinal effects of age, psychological distress, and objective cognitive performance on subjective cognitive function. Older adults (N=147, Mage = 74.17) were assessed biannually for up to six years. Subjective cognitive function, psychological distress, and neuropsychological testing were obtained at each assessment. In multilevel models with single predictors, age, poorer average task-switching and poorer memory predicted worse subjective cognitive functioning. Both average levels and within-person deviations in distress predicted worse subjective cognitive function. There were two significant interactions: one between average distress and chronological age, and the other between average memory and within-person distress. Task switching performance and distress had an additive effect on subjective cognitive function. Both individual differences (i.e., between-person differences) and fluctuations over time (i.e., within-person changes) contributed to worse subjective cognitive function. Psychological distress may help explain the relationship between objective cognitive performance and subjective cognitive function and should be assessed when patient concerns about cognitive functioning arise.

Reduced immunity to measles in adults with major depressive disorder

BACKGROUND

Depression can impair the immunogenicity of vaccine administration in adults. Whereas many vaccinations are administered in childhood, it is not known whether adolescent or adult onset depression is associated with impairments in the maintenance of protection of childhood vaccines. This study tested the hypothesis that individuals with adolescent or adult onset mood disorders would display compromised immunity to measles, a target of childhood vaccination.

METHODS

IgG antibodies to measles were quantified using a solid phase immunoassay in volunteers with bipolar disorder (BD, n = 64, mean age of onset = 16.6 ± 5.6), currently depressed individuals with major depressive disorder (cMDD, n = 85, mean age of onset = 17.9 ± 7.0), remitted individuals with a history of MDD (rMDD, n = 82, mean age of onset = 19.2 ± 8.6), and non-depressed comparison controls (HC, n = 202), all born after the introduction of the measles vaccine in the USA in 1963.

RESULTS

Relative to HC, both the cMDD group (p = 0.021, adjusted odds ratios (OR) = 0.47, confidence interval (CI) = 0.24-0.90), and the rMDD group (p = 0.038, adjusted OR = 0.50, CI = 0.26-0.97) were less likely to test seropositive for measles. Compared with unmedicated MDD participants, currently medicated MDD participants had a longer lifetime duration of illness and were less likely to test seropositive for measles.

CONCLUSIONS

Individuals with adolescent or adult onset MDD are less likely to test seropositive for measles. Because lower IgG titers are associated with increased risk of measles infection, MDD may increase the risk and severity of infection possibly because of impaired maintenance of vaccine-related protection from measles.

Within-subject associations between inflammation and features of depression: Using the flu vaccine as a mild inflammatory stimulus

BACKGROUND

Inflammation plays a role in mood and behavior that may be relevant to identifying risk factors and treatment for depression and other stress-related illnesses. The purpose of this study was to examine whether fluctuations in inflammation following a mild immune stimulus were associated with changes in daily reported features of depression for up to a week in a healthy sample of young adults.

METHODS

Forty-one undergraduate students completed daily diaries of mood, feelings of social disconnection, sleep, and physical symptoms for one week before and after receiving the seasonal influenza vaccine. Circulating plasma interleukin-6 (IL-6) was measured via blood samples taken immediately before and one day after vaccination.

RESULTS

There was a significant increase in circulating IL-6 from pre- to post-intervention (p = .008), and there was significant variability in the magnitude of IL-6 change. Greater increases in IL-6 were associated with greater mood disturbance on post-vaccine days, specifically depressed mood and cognitive symptoms.

CONCLUSIONS

Minor increases in inflammation were associated with corresponding increases in features of depression, and these associations occurred in the absence of any physical symptoms. The influenza vaccine could be used to probe causal relationships with a high degree of ecological validity, even in high-risk and vulnerable populations, to better understand the role of inflammation in the pathogenesis of depression.

Altered populations of natural killer cells, cytotoxic T lymphocytes, and regulatory T cells in major depressive disorder: Association with sleep disturbance

A subset of individuals with major depressive disorder (MDD) have impaired adaptive immunity characterized by a greater vulnerability to viral infection and a deficient response to vaccination along with a decrease in the number and/or activity of T cells and natural killer cells (NKC). Nevertheless, it remains unclear which specific subsets of lymphocytes are altered in MDD, a shortcoming we address here by utilizing an advanced fluorescence-activated cell sorting (FACS) method that allows for the differentiation of important functionally-distinct lymphocyte sub-populations. Furthermore, despite evidence that sleep disturbance, which is a core symptom of MDD, is itself associated with alterations in lymphocyte distributions, there is a paucity of studies examining the contribution of sleep disturbance on lymphocyte populations in MDD populations. Here, we measured differences in the percentages of 13 different lymphocytes and 6 different leukocytes in 54 unmedicated MDD patients (partially remitted to moderate) and 56 age and sex-matched healthy controls (HC). The relationship between self-reported sleep disturbance and cell counts was evaluated in the MDD group using the Pittsburgh Sleep Quality Index (PSQI). The MDD group showed a significantly increased percentage of CD127^low/CCR4⁺ T_reg cells, and memory T_reg cells, as well as a reduction in CD56⁺CD16^- (putative immunoregulatory) NKC counts, the latter, prior to correction for body mass index. There also was a trend for higher effector memory CD8⁺ cell counts in the MDD group versus the HC group. Further, within the MDD group, self-reported sleep disturbance was associated with an increased percentage of effector memory CD8⁺ cells but with a lower percentage of CD56⁺CD16^- NKC. These results provide important new insights into the immune pathways involved in MDD, and provide novel evidence that MDD and associated sleep disturbance increase effector memory CD8⁺ and T_reg pathways. Targeting sleep disturbance may have implications as a therapeutic strategy to normalize NKC and memory CD8⁺ cells in MDD.

Cytomegalovirus serostatus, inflammation, and antibody response to influenza vaccination in older adults: The moderating effect of beta blockade

Cytomegalovirus (CMV) has been implicated as a factor in immunosenescence, including poor antibody response to vaccination and higher immune activation and inflammation. Some people may be more or less vulnerable to the negative effects of CMV. The present investigation tested the effects of beta-blocker use and chronological age on the associations between CMV and immunity in adults aged 60-91 (N=98; 69% CMV seropositive) who were administered the trivalent influenza vaccine for up to 5years. Peak antibody response, corrected for baseline, and spring (persistent) antibody response, corrected for peak, were assessed, as well as beta-2 microglobulin (β2μ) and interleukin-6 (IL-6). In multi-level models with years at Level 1 and people at Level 2, CMV serostatus did not predict peak antibody response, but there was a 3-way interaction between CMV serostatus, age, and beta-blockers. Age was negatively associated with peak antibody, but only among adults who were CMV seropositive and taking beta-blockers. CMV seronegative adults who were not taking beta-blockers had the highest antibody persistence. CMV serostatus was not associated with β2μ or IL-6. Results suggest that CMV+ serostatus may negatively compromise antibody response to a greater degree than inflammatory markers in older adults. Furthermore, older adults who take beta-blockers may be more vulnerable to negative effects of age and CMV on peak antibody response, perhaps by virtue of their underlying health condition.

Morning vaccination enhances antibody response over afternoon vaccination: A cluster-randomised trial

OBJECTIVES

Older adults are less able to produce a protective antibody response to vaccinations. One factor that contributes to this is immune ageing. Here we examined whether diurnal variations in immune responses might extend to the antibody response to vaccination.

DESIGN

We utilised a cluster-randomised trial design.

SETTING

24 General Practices (GPs) across the West Midlands, UK who were assigned to morning (9-11am; 15 surgeries) or afternoon (3-5pm; 9 surgeries) vaccination times for the annual UK influenza vaccination programme.

PARTICIPANTS

276 adults (aged 65+ years and without a current infection or immune disorder or taking immunosuppressant medication).

INTERVENTIONS

Participants were vaccinated in the morning or afternoon between 2011 and 2013.

MAIN OUTCOME MEASURES

The primary outcome was the change in antibody titres to the three vaccine influenza strains from pre-vaccination to one month post-vaccination. Secondary outcomes of serum cytokines and steroid hormone concentrations were analysed at baseline to identify relationships with antibody responses.

RESULTS

The increase in antibody levels due to vaccination differed between morning and afternoon administration; mean difference (95% CI) for H1N1 A-strain, 293.3 (30.97-555.66) p=.03, B-strain, 15.89 (3.42-28.36) p=.01, but not H3N2 A-strain, 47.0 (-52.43 to 146.46) p=.35; those vaccinated in the morning had a greater antibody response. Cytokines and steroid hormones were not related to antibody responses. No adverse events were reported.

CONCLUSIONS

This simple manipulation in the timing of vaccine administration to favour morning vaccination may be beneficial for the influenza antibody response in older adults, with potential implications for vaccination strategies generally.

TRIAL REGISTRATION

This trial is registered with the ISRCTN (ISRCTN70898162).

The risk of new onset depression in association with influenza--A population-based observational study

IMPORTANCE

Case-reports provided evidence that influenza infections, particularly severe episodes, may exert neuronal damage in the CNS and thereby increase the risk of depression.

OBJECTIVE

It was the aim of this study to analyse the association between influenza infections and the risk of developing incident depression.

DESIGN

We conducted a case-control analysis between 2000 and 2013 using the large UK-based primary care database Clinical Practice Research Datalink (CPRD).

SETTING

This database contains anonymous longitudinal data from primary care. At present, it contains over 100 million person-years of data from some 10 million active patients.

PARTICIPANTS

We encompassed 103307 patients below the age of 80 years with an incident major depression diagnosis between 2000 and 2013, and matched each case to one control patient on age, sex, general practice, number of medical encounters, and years of history in the CPRD prior to the index date.

EXPOSURE

Major depression diagnosis was identified by READ-codes based on ICD-10 codes (F32), with a minimum of three prescriptions for antidepressant drugs recorded after the diagnosis.

MAIN OUTCOME

We calculated relative risk estimates of developing depression in association with previous influenza infections, stratified by the number, timing and severity of such events, and we adjusted for a variety of comorbidities, smoking status, alcohol intake, body mass index, use of oral corticosteroids, and benzodiazepines.

RESULTS

Patients with a previous influenza infection had an increased risk of developing depression (OR 1.30, 95%CI 1.25-1.34) compared to patients with no history of influenza infections. A recent influenza infection recorded within 30-180 days prior to the index date yielded an adjusted 1.57 (95%CI 1.36-1.81), and an increasing number of previous influenza infections was associated with increasing odds ratios (⩾ 3 recorded influenza infections, adjusted OR 1.48, 95%CI 1.22-1.81).

CONCLUSION

This study suggests that influenza infections are associated with a moderately increased risk of developing depression.

The weight of obesity on the human immune response to vaccination

Despite the high success of protection against several infectious diseases through effective vaccines, some sub-populations have been observed to respond poorly to vaccines, putting them at increased risk for vaccine-preventable diseases. In particular, the limited data concerning the effect of obesity on vaccine immunogenicity and efficacy suggests that obesity is a factor that increases the likelihood of a poor vaccine-induced immune response. Obesity occurs through the deposition of excess lipids into adipose tissue through the production of adipocytes, and is defined as a body-mass index (BMI) ≥ 30 kg/m(2). The immune system is adversely affected by obesity, and these "immune consequences" raise concern for the lack of vaccine-induced immunity in the obese patient requiring discussion of how this sub-population might be better protected.

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.

Neuroendocrine regulation of inflammation

The interaction between the sympathetic nervous system and the immune system has been documented over the last several decades. In this review, the neuroanatomical, cellular, and molecular evidence for neuroimmune regulation in the maintenance of immune homeostasis will be discussed, as well as the potential impact of neuroimmune dysregulation in health and disease.

Repetitive thought dimensions, psychological well-being, and perceived growth in older adults: a multilevel, prospective study

BACKGROUND AND OBJECTIVES

Forms of repetitive thought (RT) such as worry are clearly related to states such as anxiety and depression. However, the presence of other forms such as reminiscing suggests that RT could also relate to eudaimonic well-being (EWB). Furthermore, a largely overlooked characteristic, total tendency to engage in RT, may associate with a particular kind of EWB, namely, perceived growth (PG).

DESIGN

Older adults (N=150) were interviewed semi-annually for up to 10 waves.

METHODS

Participants completed a battery of RT measures at baseline and annual assessments of psychological well-being (PWB) and PG. Multilevel models tested the prospective, between-person relationships between baseline RT and future PWB and PG.

RESULTS

RT qualities prospectively predicted both PWB and PG: more positive valence best predicted PWB whereas more negative valence and more total RT best predicted PG. Furthermore, RT qualities largely accounted for a negative between-person relationship between PWB and PG.

CONCLUSIONS

Different qualities of RT promoted different kinds of EWB, and a negative association between different kinds of EWB could be attributed to their different RT antecedents.

In a safety net population HPV4 vaccine adherence worsens as BMI increases

Objectives

Obesity adversely inhibits antibody response to vaccination. Three doses of HPV4 may or may not provide adequate long term protection against HPV 16/18 in obese females. The aim of this study was to determine whether adherence to HPV4 vaccination in a safety net population was reduced with increasing body mass index (BMI).

Methods

We designed a historical prospective study evaluating the number and dates of HPV4 dosing that occurred from July 1, 2006 through October 1, 2009 by the demographic characteristics of the 10–26 year old recipient females. The defined dosing intervals were adapted from the literature and obesity categories were defined by the WHO.

Results

1240 females with BMI measurements received at least one dose of HPV4; 38% were obese (class I, II and III) and 25% were overweight. Females with normal BMI received on-time triplet dosing significantly more often than did the obese class II and III females (30% vs. 18%, p<0.001). Obese class II/III females have a significant 45% less chance of completing the on-time triplet HPV4 series than normal women (OR = 0.55, 95% CI: 0.37, 0.83). Pregnancy history has a significant influence on BMI and HPV4 dosing compliance in this safety net population where 71% had been gravid. Hispanic females were less likely to complete HPV4 dosing regardless of BMI (aOR = 0.39, 95% CI: 0.16, 0.95).

Conclusions

Obesity, as well as gravidity and Hispanic race, are risk factors for lack of HPV4 vaccine adherence among young females in a safety net population.

Depression inhibits the anti-inflammatory effects of leisure time physical activity and light to moderate alcohol consumption

Light to moderate alcohol consumption and leisure time physical activity (LTPA) are independently associated with lower levels of high sensitivity C-reactive protein (CRP), a predictor of cardiometabolic risk. In contrast, depression, ranging from low mood disturbance to major depressive disorder, has been associated with elevated CRP. To test the hypothesis that depression attenuates the anti-inflammatory effects of LTPA and alcohol consumption, the current study tested the moderating effect of severity of depressive symptomatology on the relation of alcohol consumption and LTPA to CRP in 222 healthy adult men and women (18-65 years of age). Given the known effects of gender on inflammation, we also examined the effects of gender on the tested interactions. Depression was assessed using the Beck Depression Inventory. Frequency of alcohol consumption, hours of LTPA per week and other coronary risk/protective factors were assessed via self-report and structured interview. Fasting blood samples were used to measure CRP and lipids. As predicted, the interaction between LTPA and depressive symptomatology was significant (F=5.29, p<.03) such that lower CRP was associated with the combination of decreased depressive symptomatology and increased LTPA. Among those with increased depressive symptoms, increased LTPA was not associated with higher CRP. Similarly, depression interacted with alcohol consumption in predicting CRP in men but not women (F=5.03, p<.008) such that for men light to moderate alcohol consumption was associated with lower CRP but only among those with decreased depressive symptoms. Light to moderate alcohol consumption was not associated with lower CRP in those with increased depressive symptom severity. The pattern of the interactions between anti-inflammatory activities such as light to moderate alcohol consumption and LTPA and psychological distress as indexed by severity of depressive symptomatology suggests an important new avenue for future research.