Vaccination response following aerobic exercise: can a brisk walk enhance antibody response to pneumococcal and influenza vaccinations?

Physical exercise, the immune system and infection risk: implications for prehabilitation and rehabilitation for solid organ transplantation candidates and recipients

PURPOSE OF REVIEW

Solid organ transplantation recipients have an increased risk of infection, exacerbated by immunosuppressant medications that need to finely balance suppression of the immune system to prevent allograft rejection while avoiding over-suppression leading to infections and malignancy. Exercise modulates immune functions, with moderate-intensity activities particularly associated with enhanced antiviral immunity and reduced infection incidence. However, investigations of the effects of exercise and physical activity on immune function and infection risk posttransplantation are scarce. This review highlights areas where the relationship between exercise, immune function and infection risk has greatest potential for benefit for solid organ transplantation and therefore greatest need for investigation.

RECENT FINDINGS

Moderate and higher intensity exercise do not appear to cause adverse immunological effects in kidney transplantation recipients, although evidence from other organ transplantation is lacking. Evidence from healthy younger and older adults suggests that regular exercise can reduce risk of respiratory infections and latent herpesvirus reactivation and improves antibody responses to vaccination, which is of great importance for organ transplantation recipients.

SUMMARY

There is a strong need for research to investigate the role of exercise on immune function and infection risk in solid organ transplantation to improve both allograft survival and long-term health of the recipient.

Effect of physical exercise on inactivated COVID-19 vaccine antibody response in the elderly

BACKGROUND

Physical exercise has been proposed as a new alternative to chemical adjuvants.

OBJECTIVE

To investigate the relationship between regular exercise and post-vaccination antibody response in the elderly.

METHODS

The study was conducted with the elderly over the age of 65. 30 participants we randomized into 2 groups and divided into exercise and control groups. The experimental group received a 12-week exercise program. The control group was followed up without any exercise. The day on which the second dose of the vaccine was administered to all participants was considered day 0. The antibody level in the serum samples was taken 15 days and 12 weeks after the vaccination. The antibody concentration was measured after the second dose of vaccination.

RESULTS

The mean antibody level in the control group was 69.4 U/ml and 56.4 U/ml 15 days and 12 weeks after the second vaccination. The mean antibody level in the exercise group was 74 U/ml and 71.6 U/ml 15 days and 12 weeks after the second vaccination.

CONCLUSIONS

Regular exercise of light to moderate intensity may increase post-vaccination antibody response in the elderly. Therefore, exercise can be used as a behavioral adjuvant to improve the vaccine efficacy in the elderly.

Multiplexed suspension array immunoassays for detection of antibodies to pneumococcal polysaccharide and conjugate vaccines

Combination and polyvalent vaccines not only provide protection against several different pathogens at the same time but can also increase vaccine protection against pathogens that have closely related pathogenic strains or serotypes. Multiplexed serological testing is a preferred method for determining the efficacy of combination and polyvalent vaccines, as it reduces the need for conducting multiple individual assays to confirm immune responses and cross-reactivity, uses less sample, and can be faster, more reliable, and more cost-effective. Bead-based suspension array technologies, such as the Luminex® xMAP® Technology, are often used for development of multiplexed serological assays for various vaccine trials and for routine testing in clinical laboratories to determine immune status of vaccinated individuals. This article reviews publications describing the development and implementation of bead-based multiplexed serological assays for detection of immune responses to polyvalent polysaccharide and conjugate vaccines against Streptococcus pneumoniae. Many of these serological assays on the bead array platform have been further optimized and expanded over time and are still widely used today.

Leisure-time physical activity and mortality from influenza and pneumonia: a cohort study of 577 909 US adults

OBJECTIVE

To examine the association of leisure-time physical activity with mortality from influenza and pneumonia.

METHODS

A nationally representative sample of US adults (aged ≥18 years) who participated in the National Health Interview Survey from 1998 to 2018 were followed for mortality through 2019. Participants were classified as meeting both physical activity guidelines if they reported ≥150 min/week of moderate-intensity equivalent aerobic physical activity and ≥2 episodes/week of muscle-strengthening activity. Participants were also classified into five volume-based categories of self-reported aerobic and muscle-strengthening activity. Influenza and pneumonia mortality was defined as having an underlying cause of death with an International Classification of Diseases, 10th Revision code of J09-J18 recorded in the National Death Index. Mortality risk was assessed using Cox proportional hazards, adjusting for sociodemographic and lifestyle factors, health conditions and influenza and pneumococcal vaccination status. Data were analysed in 2022.

RESULTS

Among 577 909 participants followed for a median of 9.23 years, 1516 influenza and pneumonia deaths were recorded. Compared with participants meeting neither guideline, those meeting both guidelines had 48% lower adjusted risk of influenza and pneumonia mortality. Relative to no aerobic activity, 10-149, 150-300, 301-600 and >600 min/week were associated with lower risk (by 21%, 41%, 50% and 41%). Relative to <2 episodes/week of muscle-strengthening activity, 2 episodes/week was associated with 47% lower risk and ≥7 episodes/week with 41% higher risk.

CONCLUSIONS

Aerobic physical activity, even at quantities below the recommended level, may be associated with lower influenza and pneumonia mortality while muscle-strengthening activity demonstrated a J-shaped relationship.

Exercise With a Novel Digital Device Increased Serum Anti-influenza Antibody Titers After Influenza Vaccination

It has been reported that some exercise could enhance the anti-viral antibody titers after vaccination including influenza and coronavirus disease 2019 vaccines. We developed SAT-008, a novel digital device, consists of physical activities and activities related to the autonomic nervous system. We assessed the feasibility of SAT-008 to boost host immunity after an influenza vaccination by a randomized, open-label, and controlled study on adults administered influenza vaccines in the previous year. Among 32 participants, the SAT-008 showed a significant increase in the anti-influenza antibody titers assessed by hemagglutination-inhibition test against antigen subtype B Yamagata lineage after 4 wk of vaccination and subtype B Victoria lineage after 12 wk (p<0.05). There was no difference in the antibody titers against subtype "A." The SAT-008 also showed significant increase in the plasma cytokine levels of IL-10, IL-1β, and IL-6 at weeks 4 and 12 after the vaccination (p<0.05). A new approach using the digital device may boost host immunity against virus via vaccine adjuvant-like effects.

Trial Registration

ClinicalTrials.gov Identifier: NCT04916145.

Exercise mobilizes diverse antigen specific T-cells and elevates neutralizing antibodies in humans with natural immunity to SARS CoV-2

Epidemiological data suggest that physical activity protects against severe COVID-19 and improves clinical outcomes, but how exercise augments the SARS-CoV-2 viral immune response has yet to be elucidated. Here we determine the antigen-specific CD4 and CD8 T-cell and humoral immunity to exercise in non-vaccinated individuals with natural immunity to SARS CoV-2, using whole-blood SARS-CoV-2 peptide stimulation assays, IFN-γ ELISPOT assays, 8-color flow cytometry, deep T-cell receptor (TCR) β sequencing, and anti-RBD-1 neutralizing antibody serology. We found that acute exercise reliably mobilized (∼2.5-fold increase) highly functional SARS-CoV-2-specific T-cells to the blood compartment in those with natural immunity to the virus. The mobilized cells reacted with spike protein (including alpha (α) and delta (δ)-variants), membrane, and nucleocapsid peptides in those previously infected but not in controls. Both groups reliably mobilized T-cells reacting with Epstein-Barr viral peptides. Exercise mobilized SARS-CoV-2 specific T-cells maintained broad TCR-β diversity with no impact on CDR3 length or V and J family gene usage. Exercise predominantly mobilized MHC I restricted (i.e. CD8⁺) SARS-CoV-2 specific T-cells that recognized ORF1ab, surface, ORF7b, nucleocapsid, and membrane proteins. SARS-CoV-2 neutralizing antibodies were transiently elevated ∼1.5-fold during exercise after infection. In conclusion, we provide novel data on a potential mechanism by which exercise could increase SARS-CoV-2 immunosurveillance via the mobilization and redistribution of antigen-specific CD8 T-cells and neutralizing antibodies. Further research is needed to define the tissue specific disease protective effects of exercise as SARS-CoV-2 continues to evolve, as well as the impact of COVID-19 vaccination on this response.

Physical activities pre- and post-COVID-19 vaccination and its implementations: A narrative review

Coronavirus disease 2019 is a severe communicable pulmonary medical problem that has been a challenging disease for everyone in the globe, but vaccines development and administration against this severe acute respiratory syndrome-inducing disease (coronavirus disease 2019) are currently yielding fabulous results. The mean duration of the coronavirus disease 2019 pandemic for this study spanned from 2020 until 2022. These manifestations are accompanied by symptoms of respiratory tract illnesses such as non-productive cough, sore throat, and nasal discharge. Relevant reviews on coronavirus disease 2019 manifestations and outcomes, consisting mainly of the infections/outbreaks, experimental information, and pre- and post-serovaccination details that occurred, were described. After a typical vaccination course, the study aims to summarize and understand more about the effectiveness of exercise on the pre-and post-coronavirus disease 2019 vaccination and its implementations. Physical activity is an immunological function adjuvant to decrease communicable disease risk and enhance immunity post-viral infection vaccination. Moderate-intensity resistance exercisesession directly before getting the influenza vaccine decreases vaccine responses in older adults, such as redness, pain, or inflammation at the injection spot or other adverse consequences compared to the inactive circumstance. However, it was reported that exercise after a shot is generally safe as long as vaccinated people feel well enough. Though exercise before or after vaccination has no negative impact on the protection afforded by the vaccine, people can exercise immediately after receiving the vaccine, as any changes in blood flow will not affect the vaccine's response. One episode of light-to-moderate-intensifying exercise after vaccination may improve the antibody reactions to influenza or the coronavirus disease 2019 vaccine. Vaccination administered pre- and post-regular exercise is an effective approach for boosting antibody responses due to its immunostimulant effects. Future research should investigate how different vaccine antibodies respond to low, moderate, and high physical activity levels.

Physical activity and acute exercise benefit influenza vaccination response: A systematic review with individual participant data meta-analysis

Whether the vaccine adjuvant potential of acute exercise is uniform among different populations, e.g., inactive persons, is unknown. This meta-analysis examines influenza vaccine antibody responses and the effect of physical activity, acute exercise, and their interaction. Inclusion criteria comprised randomized controlled trials with acute exercise intervention and influenza vaccination antibody measurements at baseline and 4-6 weeks, and participant baseline physical activity measurement; there were no exclusion criteria. Searching via six databases (Medline, Embase, CINAHL, Scopus, Web of Science, and Physiotherapy Evidence) and two clinical registries (WHO and NIH), nine studies were identified and assessed with the Cochrane revised risk-of-bias tool. Data analysis comprised one-stage random-effects generalized linear mixed-effects models with random intercept. Seven of nine identified studies, all of high risk of bias, provided data for 550 included participants. Clinical measures of antibody response tended to be higher in the acute-exercised participants compared to rested controls and physically active compared to inactive. Physical activity significantly increased H1 strain seroconversion (adjusted odds ratio (aOR) 1.69, 95%CI: 1.02-2.82) among all participants and titer response (aOR 1.20, 95%CI: 1.03-1.39) among the acute exercise group. Increasing age frequently reduced immunogenic responses whereas body mass index and sex had little-to-no effect. Adjuvant effects were more pronounced with interventions exercising the same arm in which the vaccination was administered. H1 response was increased by both physical activity and the acute exercise-physical activity interaction. Given the observed modifications by age and the subset analysis suggesting the benefit is more pronounced in older populations, future attention is due for acute exercise-PA interactions to impact vaccination response in the at-risk population of older adults. Further, we identify localized exercise as the likely most-effective protocol and encourage its use to augment the available evidence.

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.

Exercise after influenza or COVID-19 vaccination increases serum antibody without an increase in side effects

Vaccination is an effective public health measure, yet vaccine efficacy varies across different populations. Adjuvants improve vaccine efficacy but often increase reactogenicity. An unconventional behavioral "adjuvant" is physical exercise at the time of vaccination. Here, in separate experiments, we examined the effect of 90-minute light- to moderate-intensity cycle ergometer or outdoor walk/jog aerobic exercise performed once after immunization on serum antibody response to three different vaccines (2009 pandemic influenza H1N1, seasonal influenza, and COVID-19). Exercise took place after influenza vaccination or after the first dose of Pfizer-BioNTech COVID-19 vaccine. A mouse model of influenza A immunization was used to examine the effect of exercise on antibody response and the role of IFNα as a potential mechanism by treating mice with anti-IFNα antibody. The results show that 90 min of exercise consistently increased serum antibody to each vaccine four weeks post-immunization, and IFNα may partially contribute to the exercise-related benefit. Exercise did not increase side effects after the COVID-19 vaccination. These findings suggest that adults who exercise regularly may increase antibody response to influenza or COVID-19 vaccine by performing a single session of light- to moderate-intensity exercise post-immunization.

Protective Effects of Exercise Become Especially Important for the Aging Immune System in The Covid-19 Era

Aging is a complex, multietiological process and a major risk factor for most non-genetic, chronic diseases including geriatric syndromes that negatively affect healthspan and longevity. In the scenario of "healthy or good aging", especially during the COVID-19 era, the proper implementation of exercise as "adjuvant" or "polypill" to improve disease-related symptoms and comorbidities in the general population is a top priority. However, there is still a gap concerning studies analyzing influence of exercise training to immune system in older people. Therefore, the aim of this review is to provide a brief summary of well-established findings in exercise immunology and immunogerontology, but with a focus on the main exercise-induced mechanisms associated with aging of the immune system (immunosenescence). The scientific data strongly supports the notion that regular exercise as a low-cost and non-pharmacological treatment approach, when adjusted on an individual basis in elderly, induce multiple rejuvenating mechanisms: (1) affects the telomere-length dynamics (a "telo-protective" effect), (2) promote short- and long-term anti-inflammatory effects (via e.g., triggering the anti-inflammatory phenotype), 3) stimulates the adaptive immune system (e.g., helps to offset diminished adaptive responses) and in parallel inhibits the accelerated immunosenescence process, (4) increases post-vaccination immune responses, and (5) possibly extends both healthspan and lifespan.

Sustaining efficient immune functions with regular physical exercise in the COVID-19 era and beyond

The new coronavirus (SARS-CoV-2) appearance in Wuhan, China, did rise the new virus disease (COVID-19), which spread globally in a short time, leading the World Health Organization to declare a new global pandemic. To contain and mitigate the spread of SARS-CoV-2, specific public health procedures were implemented in virtually all countries, with a significant impact on society, making it difficult to keep the regular practice of physical activity. It is widely accepted that an active lifestyle contributes to the improvement of general health and preservation of cardiovascular, respiratory, osteo-muscular and immune system capacities. The positive effects of regular physical activity on the immune system have emerged as a pivotal trigger of general health, underlying the beneficial effects of physical activity on multiple physiological systems. Accordingly, recent studies have already pointed out the negative impact of physical inactivity caused by the social isolation imposed by the public sanitary authorities due to COVID-19. Nevertheless, there are still no current narrative reviews evaluating the real impact of COVID-19 on active lifestyle or even discussing the possible beneficial effects of exercise-promoted immune upgrade against the severity or progression of COVID-19. Based on the consensus in the scientific literature, in this review, we discuss how an exercise adherence could adequately improve immune responses in times of the 'COVID-19 Era and beyond'.

Regular Exercise May Restore Certain Age-Related Alterations of Adaptive Immunity and Rebalance Immune Regulation

Age-related changes of the immune system lead to an increased morbidity and mortality due to enhanced vulnerability to infectious diseases and malignancies. Recent studies revealed the important effects of physical activity on immune functions, which may largely depend on the type of exercise, its intensity and duration. However, limited information is available regarding the immunological effects of sport activities in older ages. The aim of our study was to examine the changes in a wide spectrum of lymphocyte subtypes after regular workout among healthy elderly individuals. We enrolled 29 elderly women with sedentary lifestyle (mean age: 67.03 ± 3.74 years) to take part in a 6-week long functional conditioning gymnastic exercise program. The percentages of peripheral natural killer (NK), NKT cells, T and B lymphocyte subtypes (early-/late-activated T, naïve and memory T, cytotoxic T (Tc), T-helper (Th)1, Th2, Th17, T regulatory type 1 (Tr1), CD4⁺CD127^lo/-CD25^bright Treg, as well as naïve and memory B cells) were determined by flow cytometry. Evaluation of the changes in functional capability of Treg cells was based on in vitro functional assays. At the end of exercise program, in parallel with improvements in body composition and physical performance, significant changes in naïve and memory lymphocyte ratios were observed. Importantly, levels of naïve Tc cells elevated, ratios of effector memory Tc cells decreased and distribution of memory B cells rearranged as well. Additionally, proportions of late-activated HLA-DR⁺ T cells increased, while percentages of anti-inflammatory interleukin (IL)-10 producing Tr1 cells, as well as immunosuppressive CD4⁺CD127^lo/-CD25^bright Treg cells decreased following the exercise workout. Changes observed after the regular exercise program indicate an improvement in the age-related redistribution of certain naïve and memory cell proportions and a retuned immune regulation in older ages.

Effects of non-pharmacological interventions as vaccine adjuvants in humans: a systematic review and network meta-analysis

INTRODUCTION

Psychological and behavioural may enhance vaccine effectiveness. We conducted a systematic review and network meta-analysis (NMA) to examine the effects of non-pharmacological adjuvants on vaccine effectiveness, as measured by antibody responses to vaccination.

AREAS COVERED

Electronic databases (EMBASE, Medline, PsychINFO, CINAHL) were searched from inception to 6th February 2018. This yielded 100 eligible papers, reporting 106 trials: 79 interventions associated with diet and/or nutrition; 12 physical activity interventions and 9 psychological interventions.Over half (58/106) of trials reported evidence of an enhanced antibody response to vaccination across one or more outcomes. The NMA considered the comparative effects between all intervention types, control and placebo for antibody titres (48 studies), seroconversion (25 studies) and seroprotection (23 studies) separately. The NMA provided weak evidence in support of nutritional formulae and probiotics in increasing antibody titres.

EXPERT OPINION

This review offers a comprehensive summary of the literature on non-pharmacological interventions as vaccine adjuvants. The evidence is characterised by considerable heterogeneity but provides early evidence in support of nutritional formulae and probiotic interventions. Psychological and exercise-based interventions were characterised by limited and unreliable evidence. Large, well-designed studies including consistent core outcomes and measures of intervention adherence and fidelity are required.

Combined Exercise Training and l-Glutamine Supplementation Enhances Both Humoral and Cellular Immune Responses after Influenza Virus Vaccination in Elderly Subjects

Background: Since aging affects the immune responses against vaccination, the present study evaluated the effects of L-glutamine (Gln) supplementation in the humoral and cellular immune responses in elderly subjects, practitioners or not, of physical exercise training. Methods: Eighty-four elderly people (aged 72.6 ± 6.1), non-practitioners (NP, n = 31), and practitioners of combined-exercise training (CET, n = 53) were submitted to Influenza virus vaccination and supplemented with Gln (0.3 g/kg of weight + 10 g of maltodextrin, groups: NP-Gln (n = 14), and CET-Gln (n = 26)), or placebo (10 g of maltodextrin, groups: NP-PL (n = 17), and CET-PL (n = 27)). Blood samples were collected pre (baseline) and 30 days post-vaccination and supplementation. Results: Comparing with the baseline values, whereas the NP-Gln and CET-PL groups showed higher specific-IgM levels, the CET-Gln group showed higher specific-IgM and IgA levels post-vaccination. The titer rate of hemagglutination inhibition was higher in the CET-Gln, NP-PL, and NP-Gln groups post-vaccination than baseline values. The absolute number of naive and effector CD4+ T cells was higher especially in the NP-Gln and CET-Gln groups, whilst activated CD4+ T cells were higher in CET subgroups post-vaccination. Conclusion: Our results showed that both l-glutamine supplementation and combined-exercise training can improve the immune responses to the Influenza virus vaccine in elderly subjects.

Timing of Vaccination after Training: Immune Response and Side Effects in Athletes

OBJECTIVES

Influenza vaccination was used to assess whether induction of immunity or side effects are influenced by the timing of the last training session before vaccination.

METHODS

Forty-five healthy athletes (36 male, 23 ± 8 yr, ≥5 training sessions per week, predominantly national competition level) were vaccinated with the tetravalent influenza vaccine; blood samples were collected immediately before and 1, 2, and 26 wk after vaccination. Athletes were randomly assigned to vaccination within 2 h after the last training session versus after 24-26 h. Influenza-specific T cells were quantified after stimulation with the vaccine based on intracellular cytokine staining. Antibodies (IgA, IgG, IgM) were quantified by enzyme-linked immunosorbent assay and neutralization assay. Participants documented resulting side effects and training restrictions using a standardized diary.

RESULTS

Both groups showed an increase in influenza-reactive CD4 T-cell levels, which peaked 1 wk after vaccination (fold changes to baseline; median (interquartile range), 3.7 (3.0-5.4; P < 0.001) in the 2-h group; 4.6 (2.8-7.4; P < 0.001) in the 26-h group) with no difference between groups (P = 0.52). Influenza-specific antibodies showed a significant increase after vaccination in both groups (at least 1.4-fold, each P < 0.001, no group differences; P = 0.24-0.97 for different antibody types). Only antibodies toward the Brisbane strain showed a trend toward significant differences in neutralization titers between groups (4-fold (2-17.8) in the 2-h group, 16-fold (4-32.9) in the 26-h group; P = 0.06), whereas other specificities did not differ (P = 0.16-0.72). No intergroup differences were found for side effects; no athlete reported a loss of training time due to the vaccination or its side effects.

CONCLUSION

Infection prophylaxis in elite athletes by influenza vaccination seems to be effective and safe. Timing of vaccination after prior training does not seem to require specific constraints.

Exercise-induced immune system response: Anti-inflammatory status on peripheral and central organs

A wide array of molecular pathways has been investigated during the past decade in order to understand the mechanisms by which the practice of physical exercise promotes neuroprotection and reduces the risk of developing communicable and non-communicable chronic diseases. While a single session of physical exercise may represent a challenge for cell homeostasis, repeated physical exercise sessions will improve immunosurveillance and immunocompetence. Additionally, immune cells from the central nervous system will acquire an anti-inflammatory phenotype, protecting central functions from age-induced cognitive decline. This review highlights the exercise-induced anti-inflammatory effect on the prevention or treatment of common chronic clinical and experimental settings. It also suggests the use of pterins in biological fluids as sensitive biomarkers to follow the anti-inflammatory effect of physical exercise.

Benefits of Exercise on Influenza or Pneumonia in Older Adults: A Systematic Review

A coronavirus pandemic has recently become one of the greatest threats the world is facing. Older adults are under a high risk of infection because of weaker immune systems. Therefore, the purpose of this review is to summarize the recent scientific evidence that outlines the effects of exercise on influenza or pneumonia in older adults. An electronic literature search was conducted using the WEB OF SCIENCE, SCIENCEDIRECT and GOOGLE SCHOLAR databases using the following keywords, "Exercise," "Older adult," "Influenza," and "Pneumonia." Any randomized control trials, cross-sectional and observational studies that related to this topic were all included. Twenty studies met the eligibility criteria for this review. Thirteen randomized control trials investigated the effects of exercise on the immune responses to influenza or pneumonia vaccination: seven trials employed moderate aerobic exercise, three employed resistance exercise, and the remaining three used Asian martial arts or special home-based exercises. Five cross-sectional and two observational studies examined the associations between exercise/physical condition and influenza/pneumonia. Most of the current studies suggested that prolonged moderate aerobic exercise may help to reduce the risk of influenza-related infection and improve the immune responses to influenza or pneumonia vaccination in older adults. In addition, training in traditional Asian martial arts was also found to be beneficial. Future research should focus on the different effects of moderate and vigorous exercise on influenza-related diseases.

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.

Acute exercise does not improve immune response to HPV vaccination series in adolescents

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Acute exercise is known to enhance less immunogenic response immunogenic antigens.

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In a 3-dose HPV vaccine series, exercise did not change antibody titers.

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Potential effects of exercise during first dose in series yet to be examined.

Exercise, Immunity, and Illness

It is generally accepted that moderate amounts of exercise improve immune system functions and hence reduce the risk of infection whereas athletes engaged in regular prolonged and/or intensive training have a higher than “normal” incidence of minor infections, especially of the upper respiratory tract (URT, e.g., common cold and influenza). This is likely related to regular acute (and possibly chronic) periods of exercise-induced changes in immune function. URT infections can compromise performance directly if suffered shortly before or during competition or indirectly if suffered at other times via effects on training and/or physiological adaptations. This chapter covers the effects of exercise (acute and chronic), both positive and negative, on immune function and consequent infection risk, and considers the current state-of-the-art for monitoring and assessing this in athletes.

Physical Activity Intervention for Loneliness (PAIL) in community-dwelling older adults: protocol for a feasibility study

BACKGROUND

Low-quality social relationships in older adults are strongly associated with feelings of loneliness. Physical activity interventions could reduce loneliness and improve psychological well-being, among other health benefits. The aim of this study is to examine the feasibility of a Physical Activity Intervention for Loneliness (PAIL) in community-dwelling older adults at risk for loneliness.

METHODS/DESIGN

This feasibility study is a two-arm randomised controlled trial (RCT) with a wait-list control group using a mixed-methods research design. The primary aim of the feasibility study is to estimate recruitment, retention and adherence rates; the appropriateness of the intervention design and its practicality; the acceptability of the intervention by participants; and the set of instruments and measures and primary outcome measures to inform a future large-scale randomised trial. After eligibility screening, randomisation will be conducted using computer-based random sequence generation. Baseline and post-intervention assessments for intervention and control groups will include height, weight, body mass index, resting blood pressure, physical activity using accelerometry, loneliness, social support, social networks, anxiety and depression, self-efficacy for exercise, satisfaction with social contacts, and expected outcomes and barriers for exercise using questionnaires. Focus groups will be conducted at the mid-point and post-intervention period using a phenomenological approach to analyse the participants' experiences of taking part in PAIL.

DISCUSSION

This trial will provide important information regarding the feasibility of PAIL in community-dwelling older adults at risk for loneliness using a mixed-methods approach combining quantitative and qualitative research methods.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03458793.

Reversing the immune ageing clock: lifestyle modifications and pharmacological interventions

It is widely accepted that ageing is accompanied by remodelling of the immune system, including reduced numbers of naïve T cells, increased senescent or exhausted T cells, compromise to monocyte, neutrophil and natural killer cell function and an increase in systemic inflammation. In combination these changes result in increased risk of infection, reduced immune memory, reduced immune tolerance and immune surveillance, with significant impacts upon health in old age. More recently it has become clear that the rate of decline in the immune system is malleable and can be influenced by environmental factors such as physical activity as well as pharmacological interventions. This review discusses briefly our current understanding of immunesenescence and then focuses on lifestyle interventions and therapeutic strategies that have been shown to restore immune functioning in aged individuals.

Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health Across the Lifespan

Epidemiological evidence indicates that regular physical activity and/or frequent structured exercise reduces the incidence of many chronic diseases in older age, including communicable diseases such as viral and bacterial infections, as well as non-communicable diseases such as cancer and chronic inflammatory disorders. Despite the apparent health benefits achieved by leading an active lifestyle, which imply that regular physical activity and frequent exercise enhance immune competency and regulation, the effect of a single bout of exercise on immune function remains a controversial topic. Indeed, to this day, it is perceived by many that a vigorous bout of exercise can temporarily suppress immune function. In the first part of this review, we deconstruct the key pillars which lay the foundation to this theory-referred to as the "open window" hypothesis-and highlight that: (i) limited reliable evidence exists to support the claim that vigorous exercise heightens risk of opportunistic infections; (ii) purported changes to mucosal immunity, namely salivary IgA levels, after exercise do not signpost a period of immune suppression; and (iii) the dramatic reductions to lymphocyte numbers and function 1-2 h after exercise reflects a transient and time-dependent redistribution of immune cells to peripheral tissues, resulting in a heightened state of immune surveillance and immune regulation, as opposed to immune suppression. In the second part of this review, we provide evidence that frequent exercise enhances-rather than suppresses-immune competency, and highlight key findings from human vaccination studies which show heightened responses to bacterial and viral antigens following bouts of exercise. Finally, in the third part of this review, we highlight that regular physical activity and frequent exercise might limit or delay aging of the immune system, providing further evidence that exercise is beneficial for immunological health. In summary, the over-arching aim of this review is to rebalance opinion over the perceived relationships between exercise and immune function. We emphasize that it is a misconception to label any form of acute exercise as immunosuppressive, and, instead, exercise most likely improves immune competency across the lifespan.

Assessment of serum free light chain levels in healthy adults immediately after marathon running

BACKGROUND

Immunoglobulin κ and λ free light chains (FLC) are important serum biomarkers for diagnosing and monitoring plasma cell dyscrasias (via the κ:λ FLC ratio), and assessing immune competence and activation status (via ∑FLC). FLCs are produced, in excess of heavy chains, from healthy plasma cells during immunoglobulin production, but unlike intact immunoglobulins that are cleared by cellular catabolism over a number of weeks, FLC are rapidly cleared from the bloodstream by the renal glomerulus with a half-life of 3 (κ FLC)-6 (λ FLC) hours. Marathon running has been shown to acutely and transiently decrease renal function, however, the impact of prolonged aerobic exercise on FLC levels remains unknown.

METHODS

We measured serum FLC levels in 60 runners before, and immediately after, the 2010 Eindhoven Marathon.

RESULTS

A significant increase (p<0.01) in κ FLC levels was observed after the marathon, and κ FLC correlated positively with serum creatinine levels. No changes were observed for λ FLC, and thus, there were subtle elevations in the ∑FLC and FLC ratio in some participants. Indeed, we found that 13% of participants had an abnormally increased FLC ratio upon completion of the marathon; a phenomenon previously observed in renal diseases.

CONCLUSIONS

Abnormal FLC ratios observed after exercise reflected an increase in serum κ FLC levels, which may be due to acute and transient reductions in renal function during exercise, though we also observed an increase in serum IgG and IgA and thus cannot exclude exercise-induced immune stimulation or immunoglobulin redistribution.

Exercise prior to influenza vaccination for limiting influenza incidence and its related complications in adults

BACKGROUND

Influenza is an infectious virus affecting both humans and animals. In humans, symptoms present as fever, cough, sore throat, runny nose, headache, muscle and joint pain, and malaise. The epidemiological profile of influenza is influenced by multiple factors, including transmissibility of the virus and the susceptibility of the population. Annually, influenza is estimated to infect 5% to 10% of adults, with higher rates in winter seasons in countries with seasonal variation. Exercise could be an intervention to enhance immune response and limit influenza incidence and its related complications.

OBJECTIVES

To assess the efficacy and safety of short and long-term exercise prior to influenza vaccination in enhancing influenza prevention in adults.

SEARCH METHODS

We searched CENTRAL (2015, Issue 11), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to 3 November 2015), Embase (1974 to 3 November 2015), CINAHL (1981 to 3 November 2015), LILACS (Latin American and Caribbean Health Sciences, 1982 to 3 November 2015), PEDro (1980 to 3 November 2015), SPORTDiscus (1985 to 3 November 2015), the WHO International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov (November 2015).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of short- and long-term exercise prior to influenza vaccination for the general adult population were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and checked data from the included trials using a standard form. We used the random-effects model due to differences in the type, duration, intensity and frequency of exercise in the analysis.

MAIN RESULTS

We included six trials published between 2007 and 2014 that randomised 599 adult participants. Study size ranged from 46 to 158 participants. Participants were aged between 18 years and 80 years; we could not derive gender proportions, as participants' sex was not reported in all studies. One study was available in abstract form only.We did not find a significant difference in outcomes between people who exercised and those who did not exercise before receiving influenza vaccination.Pre-vaccination exercises included endurance activities such as walking or using a treadmill, and resistance activities included biceps curls and lateral raises. Five of the studies provided one session of exercise between 25 and 50 minutes. In five studies, exercise was undertaken on the same day as the vaccination. One study provided exercise over a period of eight weeks before vaccination, with one 2½ hour supervised session, plus daily home exercise practice of 45 minutes. Exercise intensity ranged from 55% to 85% of maximal heart rate. Control group participants undertook a range of activities, including quiet rest, sitting, reading, meditation or unspecified activity.One study reported numbers of people who contracted influenza; no significant difference was reported between exercise and no-exercise participants. None of the included studies reported complications related to influenza illness. Only one study, which we assessed as providing low-quality evidence, reported numbers of people who experienced adverse events. This study reported no significant difference in outcomes between people who exercised and those who did not. No studies reported numbers of working days or days lost related to influenza illness. Only two studies reported participant-centred outcomes.Overall, study quality was unclear; we assessed five of the six included studies to have at least four unclear 'Risk of bias' domains (allocation concealment, blinding of outcome assessment, selective reporting and other bias). Insufficient reporting in four studies about selective reporting did not provide enough information to enable judgement; only two studies were included in trials registers.

AUTHORS' CONCLUSIONS

From the available evidence, we found that exercising before influenza vaccination is neither beneficial nor harmful. However, study data were limited and of low quality. Small sample sizes, study design limitations, exercise types, and focus on biochemical rather than participant-centred outcomes strongly influenced our findings.

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).

Vaccination in elite athletes

Public health vaccination guidelines cannot be easily transferred to elite athletes. An enhanced benefit from preventing even mild diseases is obvious but stronger interference from otherwise minor side effects has to be considered as well. Thus, special vaccination guidelines for adult elite athletes are required. In most of them, protection should be strived for against tetanus, diphtheria, pertussis, influenza, hepatitis A, hepatitis B, measles, mumps and varicella. When living or traveling to endemic areas, the athletes should be immune against tick-borne encephalitis, yellow fever, Japanese encephalitis, poliomyelitis, typhoid fever, and meningococcal disease. Vaccination against pneumococci and Haemophilus influenzae type b is only relevant in athletes with certain underlying disorders. Rubella and papillomavirus vaccination might be considered after an individual risk–benefit analysis. Other vaccinations such as cholera, rabies, herpes zoster, and Bacille Calmette–Guérin (BCG) cannot be universally recommended for athletes at present. Only for a very few diseases, a determination of antibody titers is reasonable to avoid unnecessary vaccinations or to control efficacy of an individual’s vaccination (especially for measles, mumps, rubella, varicella, hepatitis B and, partly, hepatitis A). Vaccinations should be scheduled in a way that possible side effects are least likely to occur in periods of competition. Typically, vaccinations are well tolerated by elite athletes, and resulting antibody titers are not different from the general population. Side effects might be reduced by an optimal selection of vaccines and an appropriate technique of administration. Very few discipline-specific considerations apply to an athlete’s vaccination schedule mainly from the competition and training pattern as well as from the typical geographical distribution of competitive sites.

Nutritional and Physical Activity Interventions to Improve Immunity

Physical activity and nutrition are important in a healthy lifestyle with potential benefits to immunity often overlooked. Infection of the upper respiratory tract, and the associated symptoms, are the most frequent presentations to general practitioners and may have significant economic and social impact. In this review, we consider the role of physical activity and nutrition in improving immunity. Evidence suggests that regular moderate activity is particularly beneficial for immune enhancement and reducing the risk of infection. We also discuss some nutritional strategies. Unfortunately, the evidence for many is weak. Avoiding nutritional deficiencies seems the most pragmatic recommendation. This can be achieved with a balanced diet. Including a variety of fruits and vegetables may help ensure adequate intake of essential nutrients with little risk of excess intake of any single nutrient. Supplementation with individual nutrients is generally not recommended. Multinutrients may be beneficial for those with a preexisting deficiency but not if normal dietary intake is sufficient. Further benefit may be gained from some supplements including probiotics, bovine colostrum, and some plant-derived products (Echinacea, black elderberry, and some polyphenols) but only in specific situations/contexts. Individuals should consider their personal needs, use caution, and avoid the indiscriminate use of supplements.

The effects of exercise on vaccination responses: a review of chronic and acute exercise interventions in humans

Vaccination programs, although feted for success in reducing infectious disease morbidity and mortality, are limited by vaccine efficacy, which is particularly problematic in populations with reduced immune function. Exercise has been identified as a behavioural factor that can improve immune function in some settings and cohorts, and therefore, in the setting of vaccination, it may serve as an adjuvant for immune responses. Here, we summarise the body of evidence that has investigated the effects of chronic or acute exercise interventions on vaccination responses. A systematic search of the literature was conducted including six major databases. Randomised control trials (RCTs), cross-sectional and observational studies that involved a variety of population samples and that employed any modality or intensity of acute exercise or chronic training prior to vaccine administration and measured any immune response were included. Twenty trials met the inclusion criteria for this review. Nine studies investigated the effect of acute exercise on the immune response to vaccination, whilst the remaining eleven studies investigated the effect of chronic exercise. Most of the current published literature suggests that exposure to either acute or chronic exercise significantly augments the immune response to vaccination. The clinical importance of this adjuvant action of exercise, if any, as well as variability in responsiveness across different cohorts, dose-response relationships and the optimal exercise modality to employ for this indication deserve further study.

Optimizing benefits of influenza virus vaccination during pregnancy: potential behavioral risk factors and interventions

Pregnant women and infants are at high risk for complications, hospitalization, and death due to influenza. It is well-established that influenza vaccination during pregnancy reduces rates and severity of illness in women overall. Maternal vaccination also confers antibody protection to infants via both transplacental transfer and breast milk. However, as in the general population, a relatively high proportion of pregnant women and their infants do not achieve protective antibody levels against influenza virus following maternal vaccination. Behavioral factors, particularly maternal weight and stress exposure, may affect initial maternal antibody responses, maintenance of antibody levels over time (i.e., across pregnancy), as well as the efficiency of transplacental antibody transfer to the fetus. Conversely, behavioral interventions including acute exercise and stress reduction can enhance immune protection following vaccination. Such behavioral interventions are particularly appealing in pregnancy because they are safe and non-invasive. The identification of individual risk factors for poor responses to vaccines and the application of appropriate interventions represent important steps towards personalized health care.

Effects of exercise on vaccine-induced immune responses

The role of exercise in health is well known; here we discuss the specific role of exercise in vaccination responses. Chronic exercise or high levels of physical activity have been shown to be related to improved vaccination responses in older adults, illustrating improved immune function, and conferring potentially significant public health benefit. Acute exercise has recently been examined as a potential adjuvant to vaccination; its promise for clinical use warrants further investigation, given current data.

Antibody and CD8+ T cell memory response to influenza A/PR/8/34 infection is reduced in treadmill-exercised mice, yet still protective

Moderate exercise may decrease the severity of influenza infection and reduce lung viral load. The possibility that an exercise-associated reduction in lung viral load early in infection could contribute to decreased serum antibody and reduced memory response were investigated. BALB/c mice exercised for 8 wk and were then infected with influenza A/PR/8/34 (intranasal route). Influenza-specific serum antibody was assessed for 6 mo post primary infection, at which time mice were infected again with influenza A/PR/8/34. After primary infection, exercise reduced morbidity/mortality, attenuated lung cytokines, and decreased serum anti-influenza IgG and IgG2a from day 14 to day 180 post primary infection. After secondary infectious challenge, exercised mice did not show any signs of illness, but had reduced serum anti-influenza IgG and IgG2a, increased IgG1, and reduced influenza-specific recruited and resident CD8+ granzyme B+ T cells within the lungs. When influenza virus was administered by an intraperitoneal route during primary infection, exercise did not alter serum anti-influenza IgG, IgG1, or IgG2a, suggesting the exercise effect was specific to the lung environment. Exercise-induced enhancement of respiratory host defense to primary influenza infection results in decreased serum antibody and lung CD8+ T cell memory response, but does not compromise resistance to secondary infectious challenge.