Young and elderly patients with type 2 diabetes have optimal B cell responses to the seasonal influenza vaccine

Comparison of Yeast and CHO Cell-Derived Hepatitis B Vaccines and Influencing Factors in Vaccine-Naïve Adults in China: Insights for Personalized Immunization Strategies

BACKGROUND

Various factors influence the immunologic responses to HBV vaccines in adults, including unchangeable individual characteristics. Personalized vaccination regimens accounting for host factors can enhance immune efficiency, particularly for adults at higher risk.

METHODS

In this two-center controlled trial, HBV vaccine-naïve participants aged 25-55 were randomly administered the two types of HBV vaccines (yeast cell-derived (YDV) or Chinese hamster ovary (CHO) cell-derived) at 0-1-6 months. Antibody titers were measured eight weeks after the final dose.

RESULTS

Overall, 289 participants with YDV and 293 participants with CHO completed the three-dose series and antibody testing. The seroprotection rates (SPRs) were comparable (97.23% vs. 98.98%; p = 0.1398), but the geometric mean concentration (GMC) was significantly higher for the CHO (1627.83 mIU/mL vs. 600.76 mIU/mL; p < 0.0001). The GMC of both regimens declined significantly in individuals aged ≥45 years and males. Unlike the YDV, the GMC of CHO was minimally affected by BMI or smoking or drinking status.

CONCLUSION

The CHO regimen may be advantageous for HBV vaccine-naïve adults aged 25-55 with BMI ≥ 25 or those who smoke or drink, in terms of immunogenicity and durability, providing insights for personalized immunization strategies.

In Vitro Treatment with Metformin Significantly Reduces Senescent B Cells Present in the Adipose Tissue of People with Obesity

BACKGROUND

Our previous work has shown that senescent B cells accumulate in the human adipose tissue (AT) of people with obesity, where they express transcripts for markers associated with the senescence-associated secretory phenotype (SASP) and secrete multiple inflammatory mediators. These functions of AT-derived B cells are metabolically supported.

OBJECTIVES

To show that Metformin (MET), a widely used hypoglycemic and antidiabetic drug, is able at least in vitro to decrease frequencies, secretory profile, and metabolic requirements of senescent B cells isolated from the AT of people with obesity.

METHODS

We recruited adult females with obesity (n = 8, age 40 ± 2 y, BMI range: 33-42) undergoing breast reduction surgery, who donated their discarded subcutaneous AT. B cells from stromal vascular fractions isolated after collagenase digestion of the AT were evaluated after in vitro incubation with MET (1 mM × 106 B cells) or with a control medium without MET for the following measures: expression of transcripts for SASP-associated markers (p16INK4a and p21CIP1/WAF1) measured by quantitative polymerase chain reaction (qPCR); secretion of inflammatory cytokines (TNF-α, IL-6, IFN-γ and IL-17A) measured by a Cytometric Bead Array); metabolic characteristics as identified by a glycolytic test and Seahorse technology, and by the expression of transcripts for glucose transporters and metabolic enzymes involved in glucose metabolic pathways, measured by qPCR. To examine differences between MET-treated compared with untreated groups, paired Student's t tests (two-tailed) were employed.

RESULTS

MET in vitro was able to reduce frequencies and numbers of senescent B cells, as identified by staining with β-galactosidase, as well as the secretion of inflammatory cytokines, the expression of transcripts for SASP, and metabolic markers that support intrinsic B cell inflammation.

CONCLUSIONS

Our results provide evidence to support the beneficial effects of MET in reducing AT-related inflammation through its effects on senescent B cells.

A Serum Multi-Parametric Analysis Identifies an Early Innate Immune Signature Associated to Increased Vaccine-Specific Antibody Production and Seroconversion in Simultaneous COVID-19 mRNA and Cell-Based Quadrivalent Influenza Vaccination

In this pilot study, a multi-parametric analysis comparing immune responses in sera of adult healthy subjects (HS) or people with type 2 diabetes mellitus (T2D) undergoing the single or simultaneous administration of mRNA-based COVID-19 and cellular quadrivalent inactivated influenza vaccines was conducted. While SARS-CoV-2 antibodies remains comparable, influenza antibody titers and seroconversion were significantly higher upon simultaneous vaccination. Magnitude of anti-influenza humoral response closely correlated with an early innate immune signature, previously described for the COVID-19 vaccine, composed of IL-15, IL-6, TNF-α, IFN-γ, CXCL-10 and here extended also to acute-phase protein Pentraxin 3. People with T2D receiving simultaneous vaccination showed a protective response comparable to HS correlating with the early induction of IFN-γ/CXCL10 and a significant reduction of the circulating glucose level due to increased oxidation of glucose digestion and consumption. These data, although preliminary and in-need of validation in larger cohorts, might be exploited to optimize future vaccination in people with chronic disorders, including diabetes.

Influenza Vaccination Uptake and Associated Factors among Individuals with Diabetes Mellitus in Spain: A Cross-Sectional Study Using Data from the European Health Interview Survey 2020

BACKGROUND

Vaccination against influenza has proven to reduce influenza-caused hospital entries, treatment times in intensive care units and hospitalisation costs for treating people with Diabetes Mellitus (DM). Despite the existing influenza vaccination recommendations for all persons with DM, in Spain, vaccination hesitancy remains substantial, and vaccination rates lag behind target. We aimed to assess predictors for influenza vaccination uptake and reasons for non-adherence among individuals with DM.

METHODS

Data from the 2020 European Health Interview Survey were analysed using uni- and multivariable logistic regression models, stratified by age group and including possible confounders and vaccination as an outcome. Associations with the sociodemographic profile, healthcare access and substance use were explored.

RESULTS

Our analysis included 2194 individuals with DM over the age of 15, showing an influenza vaccination rate of 53%. The findings revealed significant predictors of vaccination uptake, including age over 60 years and robust social support. Conversely, younger age, higher education levels, infrequent healthcare interactions and economic barriers emerged as significant obstacles to vaccination.

CONCLUSIONS

To enhance vaccination rates, targeted public health interventions should emphasise the importance of vaccination for younger, more educated individuals with DM, those facing economic barriers and those with lower levels of social support, which could bridge the existing gap in vaccination coverage.

Naturally acquired antibodies against 4 Streptococcus pneumoniae serotypes in Pakistani adults with type 2 diabetes mellitus

Immune response elicited during pneumococcal carriage has been shown to protect against subsequent colonization and infection by Streptococcus pneumoniae. The study was designed to measure the baseline serotype-specific anti-capsular IgG concentration and opsonic titers elicited in response to asymptomatic carriage in adults with and without type 2-diabetes. Level of IgG to capsular polysaccharide was measured in a total of 176 samples (124 with type 2 diabetes and 52 without type 2 diabetes) against serotype 1, 19F, 9V, and 18C. From within 176 samples, a nested cohort of 39 samples was selected for measuring the functional capacity of antibodies by measuring opsonic titer to serotypes 19F, 9V, and 18C. Next, we measured levels of IgG to PspA in 90 samples from individuals with and without diabetes (22 non-diabetes and 68 diabetes). Our results demonstrated comparable IgG titers against all serotypes between those with and without type 2-diabetes. Overall, we observed higher opsonic titers in those without diabetes as compared to individuals with diabetes for serotypes 19F and 9V. The opsonic titers for 19F and 9V significantly negatively correlated with HbA1c. For 19F, 41.66% (n = 10) showed opsonic titers ≥ 1:8 in the diabetes group as compared to 66.66% (n = 10) in the non-diabetes group. The percentage was 29.6% (n = 7) vs 66.66% (n = 10) for 9V and 70.83% (n = 17) vs 80% (n = 12) for 18C in diabetes and non-diabetes groups respectively. A comparable anti-PspA IgG (p = 0.409) was observed in those with and without diabetes, indicating that response to protein antigen is likely to remain intact in those with diabetes. In conclusion, we demonstrated comparable IgG titers to both capsular polysaccharide and protein antigens in those with and without diabetes, however, the protective capacity of antibodies differed between the two groups.

Efficacy and safety of hepatitis B vaccine: an umbrella review of meta-analyses

BACKGROUND

There is a lack of synthesis of literature to determine hepatitis B vaccine (HepB) strategies for hepatitis B virus (HBV) supported by quality evidence. We aimed to explore the efficacy and safety of HepB strategies among people with different characteristics.

RESEARCH DESIGN AND METHODS

PubMed, Cochrane Library, Embase, and Web of Science were searched for meta-analyses comparing the efficacy and safety of HepB up to July 2023.

RESULTS

Twenty-one meta-analyses comparing 83 associations were included, with 16 high quality, 4 moderate, and 1 low quality assessed by AMSTAR 2. Highly suggestive evidence supports HepB booster and HepB with 1018 adjuvant (HBsAg-1018) for improved seroprotection, and targeted and universal HepB vaccination reduced HBV infection Suggestive evidence indicated that targeted vaccination decreased the rate of hepatitis B surface antibody positivity and booster doses increased seroprotection in people aged 10-20. Weak evidence suggests potential local/systemic reaction risk with nucleotide analogs or HBsAg-1018. Convincing evidence shows HLA-DPB1*04:01 and DPB1*04:02 increased, while DPB1*05:01 decreased, hepatitis B antibody response. Obesity may reduce HepB seroprotection, as highly suggested.

CONCLUSION

Targeted vaccination could effectively reduce HBV infection, and adjuvant and booster vaccinations enhance seroprotection without significant reaction. Factors such as obesity and genetic polymorphisms may affect the efficacy.

Factors affecting HBV DNA suppression in chronic hepatitis B patients treated with tenofovir disoproxil fumarate

Background: This study aims to determine the factors affecting HBV DNA suppression in chronic hepatitis B patients with tenofovir disoproxil fumarate (TDF). Methods: A case-control was carried out from October 2021 to August 2022 on 182 chronic hepatitis B patients who had TDF therapy regularly for 24 weeks at H. Adam Malik and USU Hospitals in Medan, Indonesia. The history of the samples was obtained, followed by physical examination, and blood collection. CTLA-4 polymorphism examination was carried out using real-time PCR, while the serum CTLA-4 levels were assessed with ELISA. Results: The CTLA-4 -1661G>A polymorphism, genotype GG+AG, increased 1.52 times risk of not achieving HBV DNA suppression to TDF compared to genotype AA (p=0.041). High CTLA-4 levels increased 2.28 times risk, high HBV DNA levels increased 2.09 times risk, low ALT levels increased 1.95 times risk of not achieving HBV DNA suppression (p= 0.009, 0.026, 0.036, respectively). There was no relationship between gender, age, ethnicity, obesity, baseline AST, HBeAg, genotype, liver fibrosis and HBV DNA suppression after 24 weeks of treatment (p>0.05). Conclusions: The levels of CTLA-4, HBV DNA, ALT, and CTLA-4 -1661G>A polymorphism have a potential relationship with the suppression of HBV DNA in chronic hepatitis B patients with TDF.

Obesity accelerates age defects in B cells, and weight loss improves B cell function

BACKGROUND

We have previously shown that obesity accelerates age-associated defects in B cell function and antibody production leading to decreased secretion of protective antibodies and increased autoimmunity. We wanted to evaluate if obese adults enrolled in a voluntary weight reduction program had higher protective and lower autoimmune antibody responses similar to those observed in lean adults.

METHODS

Experiments were performed using blood isolated from an established cohort of female lean adult and elderly individuals, as well as from the blood of female adults with obesity, before and after a voluntary weight reduction program in which their Body Mass Index (BMI) was reduced 10-34% in 12 months. All participants were vaccinated with the Trivalent Inactivated Influenza vaccine. Serum samples were evaluated for the presence of pro-inflammatory cytokines and adipokines, vaccine-specific antibodies and autoimmune antibodies. We evaluated the composition of the B cell pool by flow cytometry, the expression of RNA for class switch transcription factors and pro-inflammatory markers by qPCR, the in vitro secretion of pro- and anti-inflammatory cytokines and their capacity to induce pro-inflammatory T cells.

RESULTS

Obesity, similar to aging, induced increased serum levels of pro-inflammatory cytokines and autoimmune antibodies, while vaccine-specific antibodies were reduced. In agreement with the serum results, the B cell pool of obese adults and elderly individuals was enriched in pro-inflammatory B cell subsets and was characterized by higher expression of markers associated with cell senescence, higher levels of T-bet, the transcription factor for autoimmune antibodies and lower levels of E47, the transcription factor associated with protective responses to the influenza vaccine. B cells from obese adults and elderly individuals were also able to secrete inflammatory cytokines and support the generation of inflammatory T cells. All these pro-inflammatory characteristics of B cells from obese individuals were significantly attenuated, but not completely reversed, by weight loss.

CONCLUSIONS

Although the results from our small observational study show that obesity-induced dysfunctional B cell responses, similar to those occurring during aging, are ameliorated in some but not all obese individuals after weight loss, the effects of body weight loss on mechanistic pathways are largely missing and deserve further investigation.

Impact of Obesity and Diabetes in Pregnant Women on Their Immunity and Vaccination

Pregnant women with obesity and diabetes are at increased risk of developing infections and other complications during pregnancy. Several mechanisms are involved in the immunological mechanisms that contribute to reduced immunity in these populations. Both obesity and diabetes are associated with chronic low-grade inflammation that can lead to an overactive immune response. Pregnant women with obesity and diabetes often have an increase in pro-inflammatory cytokines and adipokines, such as TNF-α, IL-6, IL-1β, leptin, and resistin, which are involved in the inflammatory response. Insulin resistance can also affect the functioning of immune cells. Furthermore, both conditions alter the composition of the gut microbiome, which produces a variety of biomolecules, including short-chain fatty acids, lipopolysaccharides, and other metabolites. These substances may contribute to immune dysfunction. In addition to increasing the risk of infections, obesity and diabetes can also affect the efficacy of vaccinations in pregnant women. Pregnant women with obesity and diabetes are at increased risk of developing severe illness and complications from COVID-19, but COVID-19 vaccination may help protect them and their fetuses from infection and its associated risks. Since both obesity and diabetes classify a pregnancy as high risk, it is important to elucidate the impact of these diseases on immunity and vaccination during pregnancy. Research examining the efficacy of the COVID-19 vaccine in a high-risk pregnant population should be of particular value to obstetricians whose patients are hesitant to vaccinate during pregnancy. Further research is needed to better understand these mechanisms and to develop effective interventions to improve immune function in these populations.

Factors affecting the immunogenicity of influenza vaccines in human

BACKGROUND

The influenza viruses pose a threat to human health and medical services, and vaccination is an important way to prevent infection. However, the effectiveness of influenza vaccines is affected by various aspects. This study aimed to explore factors related to the immune response to influenza vaccines.

METHODS

The study was conducted from September 2019 to September 2021, and a total of 593 volunteers were recruited from the Center for Disease Control and Prevention in 3 provinces in China. The hemagglutination inhibition assay was used to measure antibody levels. The Chi-square test, multivariable logistic regression analysis, and sum-rank test were used to analyze the factors associated with influenza vaccine immune response.

RESULTS

The Chi-square test showed that seroconversion rates and response rate were associated with age group, vaccination history, chronic conditions, the frequency of colds, and region (P < 0.05). The multivariable logistic regression analysis showed that age was an important factor that affected participants' seroconversion rates for A/H1N1, A/H3N2, B/Victoria, and response status (18-64 vs. ≤5: OR = 2.77, P < 0.001; ≥65 vs. ≤5: OR = 0.38, P = 0.01; 18-64 vs. ≤5: OR = 2.64, P = 0.03). Vaccination history was also an affecting factor for A/H1N1, B/Victoria, and response status (yes vs. no: OR = 0.4 / 0.44 / 0.25, P < 0.001). The frequency of colds and chronic conditions were also affecting factors for participants' seroconversion rates and response levels to different degrees. The sum-rank test showed that the fold changes for A/H1N1, B/Victoria, and B/Yamagata were associated with age group and vaccination history (P < 0.01). The fold changes for A/H3N2 were associated with the frequency of colds (P < 0.05), and those for B/Victoria were associated with gender and chronic conditions (P < 0.05).

CONCLUSIONS

Vaccination history, age, health condition, and frequency of colds were important factors affecting the seroconversion rate of the influenza vaccine in human. There is a need for developing optimized vaccination strategies for vulnerable groups to improve the efficacy of influenza vaccines in human.

The relationship between triglyceride, cholesterol and lipoprotein levels, and immune responses to hepatitis B vaccine

Cholesterol homeostasis disorder and hypertriglyceridemia, as common metabolic conditions, have rarely been reported to affect the immune responses to the hepatitis B vaccine. Our study found that higher high-density lipoprotein (HDL) level showed a significant relationship with positive anti-HBs results (cOR = 1.479, 95% CI: 1.150, 1.901, p = 0.002; aOR = 1.304, 95% CI: 1.006, 1.691, p = 0.045), especially in individuals aged 18- to 40-year-old, female, smoking more than 100 cigarettes in life, and drinking more than 12 times every year. Lower low-density lipoprotein (LDL) level was associated with a negative anti-HBs result among participants aged 18- to 40-year-old, and participants who were obese. Higher level of HDL and lower level of LDL may be protective factors of better immune effect of hepatitis B vaccine. More research should be conducted to investigate the influence of the cholesterol level on the immune responses to the hepatitis B vaccine, and more in-depth research should be performed to uncover the mechanism.

Reduced antibody response to COVID-19 vaccine composed of inactivated SARS-CoV-2 in diabetic individuals

Background

Patients with type 2 diabetes mellitus (T2DM) are at increased risk for COVID-19 related morbidity and mortality. Antibody response to COVID-19 vaccine in T2DM patients is not very clear. The present work aims to evaluate the antibody response to the inactivated SARS-CoV-2 vaccine in this population.

Methods

Two groups of subjects with no history of SARS-CoV-2 infection were included: 63 T2DM patients and 56 non-T2DM controls. Each participant received two doses of inactivated COVID-19 vaccine. IgG antibodies against the nucleocapsid (N) and spike (S) proteins of SARS-CoV-2 (anti-N/S IgG) and receptor binding domain (RBD) proteins (anti-RBD IgG) were quantitatively evaluated by the electrochemiluminescence immunoassays, respectively.

Results

It was observed that the positive rates and titers of anti-N/S IgG and anti-RBD IgG in T2DM patients were significantly lower than those in controls, respectively (anti-N/S: 85.7 vs. 98.2%, P = 0.034; 25.48 vs. 33.58 AU/ml P = 0.011; anti-RBD: 85.7 vs. 96.4%, P = 0.044; 15.45 vs. 22.25 AU/ml, P = 0.019). Compared to non-T2DM subjects, T2DM patients with uncontrolled glycemia showed lower positive antibody rates and titers (anti-N/S IgG: 75% and 13.30 AU/ml; anti-RBD IgG: 75% and 11.91 AU/ml, respectively, all P < 0.05), while T2DM patients with controlled glycemia had similar positive antibody rates and titers (anti-N/S IgG: 94.3% and 33.65 AU/ml; and anti-RBD IgG: 94.3% and 19.82 AU/ml, respectively, all P > 0.05).

Conclusion

In the analysis performed, the data indicate that T2DM patients with uncontrolled glycemia showed a lower level of IgG antibodies compared to non-diabetic controls and individuals with controlled glycemia when immunized with the inactivated COVID-19 vaccine.

DYNAMIC cohort study evaluating metabolic predictors of influenza vaccine immune response in older adults

Immunosenescence (age-related immune dysfunction) and inflamm-aging contribute to suboptimal immune responses in older adults to standard-dose influenza vaccines, which may be exacerbated in those with metabolic co-morbidities. We sought to investigate metabolic factors/predictors of influenza vaccine immune response in an older adult (age ≥65 years) cohort in Singapore, where influenza typically circulates year-round. The primary outcome for the DYNAMIC prospective cohort study was haemagglutination-inhibition titer (HAI) response to each of the trivalent inactivated influenza vaccine strains at day 28 (D28) compared to baseline (D0), as assessed by seroconversion and D28/D0 log2 HAI fold rise. Baseline blood samples were tested for total Vitamin D (25-(OH) D) levels. We enrolled 234 participants in June-Dec 2017. Two hundred twenty completed all study visits. The median age was 71 [IQR 68-75] years, 67 (30.5%) had diabetes mellitus (DM), and the median BMI was 24.9 [IQR 22.2-27.8] kg/m². Median baseline totals 25-(OH) D was 29 [IQR: 21-29] ng/ml. Age, DM, obesity, and baseline 25-(OH) D were not associated with HAI fold rise in multivariable analysis. More recent prior influenza vaccination and higher baseline HAI titers were associated with lower HAI fold rise for influenza A/HK/H3N2. Physical activity was associated with a higher HAI fold rise for influenza A/HK/H3N2 in a dose-response relationship (p-test for trend = 0.015). Older adults with well-controlled metabolic co-morbidities retain HAI response to the influenza vaccine, and physical activity had a beneficial effect on immune response, particularly for influenza A/HK/H3N2.

Immunogenicity of COVID-19 vaccines in patients with diabetes mellitus: A systematic review

PURPOSE

To evaluate the immunogenicity of COVID-19 vaccines in patients with diabetes mellitus (DM) through a systematic approach.

METHOD

A comprehensive search was conducted in PubMed, Scopus, and Web of Science with no time restrictions. The search was based on the three main concepts: Covid-19, Vaccine immunogenicity and Diabetes Mellitus.

RESULTS

After excluding irrelevant studies, 16 studies remained for the quantitative assay. Among the sixteen studies, eleven had controls. Type of diabetes was specifically mentioned in six studies (T2DM; n=4, T1DM and T2DM; n=2). Twelve of the included studies were conducted on the immunogenicity of vaccines that included mRNA vaccines (i.e. BNT162b2 and mRNA-1273) in DM, five studies included vector-based vaccines (i.e. Ad5-nCoV and ChAdOx1-S), and five studies assessed the immunogenicity of vaccines in DM, including inactivated vaccines (i.e. BBV-152, CoronaVac, Sinopharm or SinoVac). Most of the current studies indicate lower antibody response in patients with DM compared to individuals without DM, after the second dose of vaccine and irrespective of vaccine type. Several studies have shown that higher age and higher BMI are associated with lower antibody response, while optimum glycemic control and higher GFR are associated with higher antibody response among patients with DM.

CONCLUSION

Immunogenicity of the vaccines has mostly been reported to be lower among patients with DM compared to healthy controls. There are also few studies assessing variables that significantly affect this association, including age, type of diabetes, BMI, glycemic control and eGFR. Investigating these associations could help us provide the most advantageous condition for patients with DM before, during and after vaccination for optimum antibody response. Many unresolved issues concerning potential factors affecting vaccine immunogenicity, including type of vaccine, numbers of administered doses, re-vaccination intervals and hyperglycemia in patients with DM need to be addressed through future research.

Indoxyl Sulfate Alters the Humoral Response of the ChAdOx1 COVID-19 Vaccine in Hemodialysis Patients

Background and aims: Vaccination for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is strongly recommended. The efficacy of SARS-CoV-2 vaccine for patients with end-stage renal disease is low. Indoxyl sulfate (IS) is a representative protein bound uremic toxin arousing immune dysfunction in CKD patients. It is unknown whether IS impairs the efficacy of vaccines for SARS-CoV-2. Materials and Methods: From 1 June 2021, to 31 December 2021, hemodialysis patients (n = 358) and a control group (n = 59) were eligible to receive the first dose of the ChAdOx1 COVID-19 vaccine. Titer measurements indicative of the humoral response (anti-S1 IgG and surrogate virus neutralization test (sVNT) results) and indoxyl sulfate concentration measurement were performed 4 weeks after ChAdOx1 vaccine injection. Results: The serum concentrations of anti-S1 IgG were 272 ± 1726 AU/mL and 2111 ± 4424 AU/mL in hemodialysis patients and control group (p < 0.05), respectively. The sVNT values were 26.8 ± 21.1% and 54.0 ± 20.2% in the hemodialysis and control groups (p < 0.05), respectively. There was a decreasing trend for the anti-S1 IgG titer from the lowest to highest quartile of IS (p < 0.001). The patients with higher concentrations of IS had lower sVNT (p for trend < 0.001). Conclusion: Hemodialysis patients had weaker humoral immunity after the first dose of the ChAdOx1 vaccine. Higher concentration of IS altered the development of anti-S1 antibodies and sVNT-measured neutralization.

Metformin Enhances B Cell Function and Antibody Responses of Elderly Individuals With Type-2 Diabetes Mellitus

Our previous work has shown that young and elderly patients with Type-2 Diabetes Mellitus (T2DM) treated with Metformin have optimal B cell function and serum antibodies specific for the seasonal influenza vaccine. In this paper, we have evaluated B cell function and the metabolic requirements of B cell antibody responses in elderly T2DM patients (E_T2DM) taking or not Metformin, and compared to those of healthy elderly (E_H) and healthy young (Y_H) individuals. Results show that Metformin significantly increases in vivo B cell function, measured by influenza vaccine-specific serum antibodies, in E_T2DM patients to the levels observed in E_H and more importantly in Y_H individuals. Metformin also decreases the frequencies of pro-inflammatory B cell subsets, as well as intrinsic inflammation and metabolic requirements of peripheral B cells from E_T2DM. This hyper-metabolic phenotype of B cells from E_T2DM is needed to support intrinsic inflammation, measured by the expression of transcripts for markers of the senescence-associated secretory phenotype (SASP), and the secretion of autoimmune antibodies. Importantly, B cell function in E_T2DM patients taking Metformin is not only increased as compared to that in E_T2DM patients not taking Metformin, but is comparable to B cell function measured in Y_H individuals. These results altogether strongly support the anti-aging effects of Metformin on humoral immunity.

BNT162b2 vaccine effectiveness in chronic kidney disease patients – an observational study

Background

chronic kidney disease (CKD) is a risk factor for severe COVID-19. We aimed to evaluate real-life effectiveness of the BNT162b2 mRNA vaccine for a range of outcomes in patients with CKD compared to matched controls.

Methods

Data from Israel's largest healthcare organization were retrospectively used. Vaccinated CKD (eGFR&lt;60ml/min/1.73m2) and maintenance dialysis patients were matched to vaccinated controls without CKD (eGFR&gt; = 60ml/min/1.73m2) according to demographic and clinical characteristics. Study outcomes included documented infection with SARS-CoV-2, symptomatic infection, COVID-19 related hospitalization, severe disease, and death. Vaccine effectiveness was estimated as the risk ratio [RR] at days 7-28 following the second vaccine dose, using the Kaplan–Meier estimator. Effectiveness measures were also evaluated separately for various stages of CKD.

Results

There were 67,861 CKD patients not treated with dialysis, 2,606 hemodialysis patients, and 70,467 matched controls. The risk of sever disease (RR1.84, 95% CI 0.95-2.67) and death (RR 2.00, 95% CI 0.99-5.20) was increased in non-dialysis CKD patients compared with controls without CKD following vaccination.

For the subgroup of patients with eGFR below 30 ml/min/1.73m2, the risk of severe disease and death was increased compared to controls (RR 6.42, 95% CI 1.85-17.51 and RR 8.81, 95% CI 1.63-13.81, respectively). The risks for all study outcomes was increased in hemodialysis patients, compared with controls.

Conclusion

Two doses of the BNT162b2 vaccine were found less efficient for patients with eGFR&lt;30ml/min/1.73m2. Risk in hemodialysis patients is increased for all outcomes. These results suggest prioritizing patients with eGFR&lt;30ml/min/1.73m2 for booster shots, pre and post exposure prophylaxis, and early COVID-19 therapy.

COVID-19 and the Endocrine System: A Review of the Current Information and Misinformation

Coronavirus disease 2019 (COVID-19) infection primarily involves the respiratory system but has many noteworthy extra pulmonary manifestations as well. We write this review to highlight the basis of some pathophysiological mechanisms of COVID-19 infection-induced endocrine dysfunction. Different scientific databases and institutional websites were searched to collect and consolidate the most up-to-date data relating to COVID-19 infection and endocrine systems. Hypopituitarism, central diabetes insipidus, SIADH, thyroid abnormalities, hyperglycemia, adrenal insufficiency, orchitis and alteration in sperm morphology have been reported in case reports of patients with COVID-19 infection. Data focusing on COVID-19 vaccination was also searched to summarize the effect, if any, on the endocrine system. Endocrinopathies noted post COVID-19 vaccination, including cases of adrenal hemorrhage, new onset Type II Diabetes Mellitus and subacute thyroiditis, are also discussed in this review. This review calls attention to the misinformation relating to COVID-19 vaccination with supposed endocrine effects such as infertility and problems with pregnancy. Rebutting these misconceptions can help increase compliance and maximize COVID-19 vaccination to the public.

The impact of glucose tolerance state on seropositivity rate after hepatitis B vaccination

Immunization is recommended for people with diabetes mellitus (DM), but little information is available on their seropositivity rates. To determine the impact of glucose tolerance state on seropositivity rate after hepatitis B vaccination, we included 7645 adult participants from the National Health and Nutrition Examination Survey 2005-2016 who reported three doses of hepatitis B vaccine and were seropositive for anti-hepatitis B surface antibody (≥ 12.0 mIU/mL), after exclusion of those positive for anti-hepatitis B core antibody and/or hepatitis B surface antigen. We classified the states of glucose tolerance as normal glucose tolerance (NGT, 61.68%), abnormal glucose tolerance (AGT, 26.02%), or DM (13.30%). We observed a stepwise decline in hepatitis B seropositivity rate from NGT (53.64%) to AGT (45.52%) to DM (28.84%) (P < 0.0001). We confirmed these results after standardization for age and BMI (P < 0.0001 for all subgroup analyses) and in subgroup analyses by gender and racial/ethnic group. Dysregulated glucose metabolism is associated with a decreased seropositivity rate after hepatitis B vaccination. Our observations suggest that regular follow-up screening for anti-hepatitis B surface antibody, with additional booster vaccination as necessary, is especially important in patients with DM. Whether a similar phenomenon exits for other vaccines, especially COVID-19, remains to be investigated.

Impact of diabetes status on immunogenicity of trivalent inactivated influenza vaccine in older adults

Individuals with type 2 diabetes mellitus experience high rates of influenza virus infection and complications. We compared the magnitude and duration of serologic response to trivalent influenza vaccine in adults aged 50–80 with and without type 2 diabetes mellitus. Serologic response to influenza vaccination was similar in both groups: greater fold‐increases in antibody titer occurred among participants with lower pre‐vaccination antibody titers. Waning of antibody titers was not influenced by diabetes status.

The Efficacy of COVID-19 Vaccines in Chronic Kidney Disease and Kidney Transplantation Patients: A Narrative Review

The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic has posed a huge threat to global health because of its rapid spread and various mutant variants. Critical illness occurs in the elderly and vulnerable individuals, such as those with chronic kidney disease. The severity of SARS-CoV-2 infection is associated with the severity of chronic kidney disease (CKD)and even kidney transplantation (KT) because of the chronic use of immunosuppressive agents. To develop adaptive immunity against SARS-CoV-2, vaccination against the spike protein is important. Current phase III trials of vaccines against SARS-CoV-2 have not focused on a specific group of individuals, such as patients with CKD or those undergoing dialysis or kidney transplantation. Chronic use of immunosuppressive agents might disturb the immune response to the SARS-CoV-2 spike protein. On the basis of limited evidence, the immune compromised status of CKD patients might decrease neutralizing antibody development after a single dose of a specific vaccine. Boosting dosage more than the protocol might increase the titer of the neutralizing antibody in CKD patients. Further evidence is needed to understand the factors disturbing the immunogenicity of the SARS-CoV-2 vaccine, and CKD patients should receive the recommended dose of the SARS-CoV-2 vaccine due to their relatively immune compromised status.

B Cell Immunosenescence

Innate and adaptive immune responses decline with age, leading to greater susceptibility to infectious diseases and reduced responses to vaccines. Diseases are more severe in old than in young individuals and have a greater impact on health outcomes such as morbidity, disability, and mortality. Aging is characterized by increased low-grade chronic inflammation, so-called inflammaging, that represents a link between changes in immune cells and a number of diseases and syndromes typical of old age. In this review we summarize current knowledge on age-associated changes in immune cells with special emphasis on B cells, which are more inflammatory and less responsive to infections and vaccines in the elderly. We highlight recent findings on factors and pathways contributing to inflammaging and how these lead to dysfunctional immune responses. We summarize recent published studies showing that adipose tissue, which increases in size with aging, contributes to inflammaging and dysregulated B cell function.

COVID-19 Vaccination for Endocrine Patients: A Position Statement from the Korean Endocrine Society

Since the first outbreak of coronavirus disease 2019 (COVID-19), ongoing efforts have been made to discover an efficacious vaccine against COVID-19 to combat the pandemic. In most countries, both mRNA and DNA vaccines have been administered, and their side effects have also been reported. The clinical course of COVID-19 and the effects of vaccination against COVID-19 are both influenced by patients' health status and involve a systemic physiological response. In view of the systemic function of endocrine hormones, endocrine disorders themselves and the therapeutics used to treat them can influence the outcomes of vaccination for COVID-19. However, there are very limited data to support the development of clinical guidelines for patients with specific medical backgrounds based on large clinical trials. In the current severe circumstances of the COVID-19 pandemic, position statements made by clinical specialists are essential to provide appropriate recommendations based on both medical evidence and clinical experiences. As endocrinologists, we would like to present the medical background of COVID-19 vaccination, as well as precautions to prevent the side effects of COVID-19 vaccination in patients with specific endocrine disorders, including adrenal insufficiency, diabetes mellitus, osteoporosis, autoimmune thyroid disease, hypogonadism, and pituitary disorders.

Antibody Responsiveness to Influenza: What Drives It?

The induction of a specific antibody response has long been accepted as a serological hallmark of recent infection or antigen exposure. Much of our understanding of the influenza antibody response has been derived from studying antibodies that target the hemagglutinin (HA) protein. However, growing evidence points to limitations associated with this approach. In this review, we aim to highlight the issue of antibody non-responsiveness after influenza virus infection and vaccination. We will then provide an overview of the major factors known to influence antibody responsiveness to influenza after infection and vaccination. We discuss the biological factors such as age, sex, influence of prior immunity, genetics, and some chronic infections that may affect the induction of influenza antibody responses. We also discuss the technical factors, such as assay choices, strain variations, and viral properties that may influence the sensitivity of the assays used to measure influenza antibodies. Understanding these factors will hopefully provide a more comprehensive picture of what influenza immunogenicity and protection means, which will be important in our effort to improve influenza vaccines.

Influenza vaccination in the elderly boosts antibodies against conserved viral proteins and egg-produced glycans

Seasonal influenza vaccination elicits a diminished adaptive immune response in the elderly, and the mechanisms of immunosenescence are not fully understood. Using Ig-Seq, we found a marked increase with age in the prevalence of cross-reactive (CR) serum antibodies that recognize both the H1N1 (vaccine-H1) and H3N2 (vaccine-H3) components of an egg-produced split influenza vaccine. CR antibodies accounted for 73% ± 18% of the serum vaccine responses in a cohort of elderly donors, 65% ± 15% in late middle-aged donors, and only 13% ± 5% in persons under 35 years of age. The antibody response to non-HA antigens was boosted by vaccination. Recombinant expression of 19 vaccine-H1+H3 CR serum monoclonal antibodies (s-mAbs) revealed that they predominantly bound to non-HA influenza proteins. A sizable fraction of vaccine-H1+H3 CR s-mAbs recognized with high affinity the sulfated glycans, in particular sulfated type 2 N-acetyllactosamine (Galβ1-4GalNAcβ), which is found on egg-produced proteins and thus unlikely to contribute to protection against influenza infection in humans. Antibodies against sulfated glycans in egg-produced vaccine had been identified in animals but were not previously characterized in humans. Collectively, our results provide a quantitative basis for how repeated exposure to split influenza vaccine correlates with unintended focusing of serum antibody responses to non-HA antigens that may result in suboptimal immunity against influenza.

Vaccine responses in ageing and chronic viral infection

Over the last few decades, changing population demographics have shown that there are a growing number of individuals living past the age of 60. With this expanding older population comes an increase in individuals that are more susceptible to chronic illness and disease. An important part of maintaining health in this population is through prophylactic vaccination, however, there is growing evidence that vaccines may be less effective in the elderly. Furthermore, with the success of anti-viral therapies, chronic infections such as HIV are becoming increasingly prevalent in older populations and present a relatively unstudied population with respect to the efficacy of vaccination. Here we will examine the evidence for age-associated reduction in antibody and cellular responsiveness to a variety of common vaccines and investigate the underlying causes attributed to this phenomenon, such as inflammation and senescence. We will also discuss the impact of chronic viral infections on immune responses in both young and elderly patients, particularly those living with HIV, and how this affects vaccinations in these populations.

Assessing Vaccine Protection for Older Adults with Diabetes: A Systematic Review

Immunosenescence and comorbidities increase the susceptibility of older adults with diabetes mellitus (DM) to vaccine-preventable diseases, hospitalization, disability, or death. This systematic review synthesizes research on protecting older adults with DM during pandemics, exploring vaccine safety, tolerance, and vaccination uptake by older adults in anticipation of seasonal influenza outbreaks during the current COVID-19 threat. Addressed were: (a) age-related factors influencing the effectiveness of vaccines against infectious disease in older adults; (b) vaccine safety, tolerance, effectiveness for older persons with DM; and (c) issues affecting older adults accepting immunization recommendations. Medline and CINAHL databases yielded 214 studies with 43 meeting inclusion criteria (32 descriptive and 11 controlled trials). Findings show altered glycemic control stimulates proinflammatory mediators, increasing infection risk, vaccines, and annual revaccinations safely reduce hospitalization rates, mortality outcomes, without affecting glycemic control. However, vaccines fail to evoke optimal antibody responses in older adults. Unawareness, fear of side effects, tend to lower vaccination participation.

Thymic Aging May Be Associated with COVID-19 Pathophysiology in the Elderly

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the global pandemic of coronavirus disease 2019 (COVID-19) and particularly exhibits severe symptoms and mortality in elderly individuals. Mounting evidence shows that the characteristics of the age-related clinical severity of COVID-19 are attributed to insufficient antiviral immune function and excessive self-damaging immune reaction, involving T cell immunity and associated with pre-existing basal inflammation in the elderly. Age-related changes to T cell immunosenescence is characterized by not only restricted T cell receptor (TCR) repertoire diversity, accumulation of exhausted and/or senescent memory T cells, but also by increased self-reactive T cell- and innate immune cell-induced chronic inflammation, and accumulated and functionally enhanced polyclonal regulatory T (Treg) cells. Many of these changes can be traced back to age-related thymic involution/degeneration. How these changes contribute to differences in COVID-19 disease severity between young and aged patients is an urgent area of investigation. Therefore, we attempt to connect various clues in this field by reviewing and discussing recent research on the role of the thymus and T cells in COVID-19 immunity during aging (a synergistic effect of diminished responses to pathogens and enhanced responses to self) impacting age-related clinical severity of COVID-19. We also address potential combinational strategies to rejuvenate multiple aging-impacted immune system checkpoints by revival of aged thymic function, boosting peripheral T cell responses, and alleviating chronic, basal inflammation to improve the efficiency of anti-SARS-CoV-2 immunity and vaccination in the elderly.

COVID-19 vaccination in patients with diabetes mellitus: Current concepts, uncertainties and challenges

BACKGROUND AND AIMS

To summarize the available evidence on the use COVID-19 vaccines in patients with diabetes mellitus.

METHODS

We performed a thorough literature search with regard to COVID-19 vaccines in patients with type 1 and type 2 diabetes mellitus.

RESULTS

The novel coronavirus disease (COVID-19) tends to portend a poor prognosis in patients with diabetes mellitus (DM). Primary prevention remains the mainstay for mitigating the risks associated with COVID-19 in patients with DM. A significant step in primary prevention is timely vaccination. Routine vaccination against pneumococcal pneumonia, influenza, and hepatitis B is recommended in patients with DM with good efficacy and reasonable safety profile. With clinical data supporting a robust neutralizing antibody response in COVID-19 patients with DM, vaccination in individuals with DM is justified. In fact, as the burden of the disease is borne by people with DM, COVID-19 vaccination should be prioritized in individuals with DM. Multiple unresolved issues with regard to preferred vaccine type, vaccine efficacy and durability, frequency of administration, vaccination in children (<18 years) and pregnant/lactating women however remain, and need to be addressed through future research.

CONCLUSIONS

Patients with type 1 and type 2 diabetes mellitus are at a high risk of poor prognosis with COVID-19 and vaccination should be prioritized in them. However, many unresolved issues with regard to COVID-19 vaccination need to be addressed through future research.

Aging induces B cell defects and decreased antibody responses to influenza infection and vaccination

Background

Aging is characterized by a progressive decline in the capacity of the immune system to fight influenza virus infection and to respond to vaccination. Among the several factors involved, in addition to increased frailty and high-risk conditions, the age-associated decrease in cellular and humoral immune responses plays a relevant role. This is in large part due to inflammaging, the chronic low-grade inflammatory status of the elderly, associated with intrinsic inflammation of the immune cells and decreased immune function.

Results

Aging is usually associated with reduced influenza virus-specific and influenza vaccine-specific antibody responses but some elderly individuals with higher pre-exposure antibody titers, due to a previous infection or vaccination, have less probability to get infected. Examples of this exception are the elderly individuals infected during the 2009 pandemic season who made antibodies with broader epitope recognition and higher avidity than those made by younger individuals. Several studies have allowed the identification of B cell intrinsic defects accounting for sub-optimal antibody responses of elderly individuals. These defects include 1) reduced class switch recombination, responsible for the generation of a secondary response of class switched antibodies, 2) reduced de novo somatic hypermutation of the antibody variable region, 3) reduced binding and neutralization capacity, as well as binding specificity, of the secreted antibodies, 4) increased epigenetic modifications that are associated with lower antibody responses, 5) increased frequencies of inflammatory B cell subsets, and 6) shorter telomeres.

Conclusions

Although influenza vaccination represents the most effective way to prevent influenza infection, vaccines with greater immunogenicity are needed to improve the response of elderly individuals. Recent advances in technology have made possible a broad approach to better understand the age-associated changes in immune cells, needed to design tailored vaccines and effective therapeutic strategies that will be able to improve the immune response of vulnerable individuals.

Aging affects sex- and organ-specific trace element profiles in mice

A decline of immune responses and dynamic modulation of the redox status are observed during aging and are influenced by trace elements such as copper, iodine, iron, manganese, selenium, and zinc. So far, analytical studies have focused mainly on single trace elements. Therefore, we aimed to characterize age-specific profiles of several trace elements simultaneously in serum and organs of adult and old mice. This allows for correlating multiple trace element levels and to identify potential patterns of age-dependent alterations. In serum, copper and iodine concentrations were increased and zinc concentration was decreased in old as compared to adult mice. In parallel, decreased copper and elevated iron concentrations were observed in liver. The age-related reduction of hepatic copper levels was associated with reduced expression of copper transporters, whereas the increased hepatic iron concentrations correlated positively with proinflammatory mediators and Nrf2-induced ferritin H levels. Interestingly, the age-dependent inverse regulation of copper and iron was unique for the liver and not observed in any other organ. The physiological importance of alterations in the iron/copper ratio for liver function and the aging process needs to be addressed in further studies.

Age-related factors that affect B cell responses to vaccination in mice and humans

Aging significantly changes the ability to respond to vaccinations and infections. In this review, we summarize published results on age-related changes in response to infection with the influenza virus and on the factors known to increase influenza risk infection leading to organ failure and death. We also summarize how aging affects the response to the influenza vaccine with a special focus on B cells, which have been shown to be less responsive in the elderly. We show the cellular and molecular mechanisms contributing to the dysfunctional immune response of the elderly to the vaccine against influenza. These include a defective interaction of helper T cells (CD4+) with B cells in germinal centers, changes in the microenvironment, and the generation of immune cells with a senescence-associated phenotype. Finally, we discuss the effects of aging on metabolic pathways and we show how metabolic complications associated with aging lead to immune dysfunction.

The intentions to get vaccinated against influenza and actual vaccine uptake among diabetic patients in Ningbo, China: identifying motivators and barriers

BACKGROUND

Health authorities recommend influenza vaccination to diabetic patients. Nevertheless, the vaccination coverage of adults was low in China. This study aimed to estimate influenza vaccination intentions and actual uptake among diabetic patients in China and identify the motivators and barriers associated with vaccination.

METHODS

During Nov 2016-Jan 2017, 1960 diabetic patients were invited to participate in the investigation about influenza vaccination based on health belief model (HBM). To link vaccination intention to behavior, a follow-up survey was conducted to collect vaccination records of the 2016-2017 season. Predictors of the motivation to obtain influenza vaccination were assessed using logistic regressions.

RESULTS

1914 diabetic patients completed the survey. 46.13% participants reported intentions to be vaccinated against influenza and 7.84% actually received vaccination. In the multivariate models, while all the domains of HBM constructs were associated with intentions, age, increasing numbers of comorbidity, urban residents, perceived susceptibility, perceived benefits, free vaccination, and vaccination history displayed positive associations with vaccine uptake while increasing income and perceptions of barriers were negative predictors of vaccine uptake. Besides, interactions between perceived susceptibility and healthcare workers' (HCW's) recommendation, perceived severity and benefits, perceived severity and health-seeking behaviors, perceived benefits, and influence of family/friends had a significant positive effect modification on the vaccine uptake.

CONCLUSION

To improve diabetic patients' influenza vaccination and close the intention-behavior gap, multipronged strategies are required not only to increase vaccination intention by promoting HCW's recommendation to improve perceptions about influenza vaccination but also facilitate a follow through on initial intentions by implementing free influenza vaccination program funded by the government.

O-GlcNAc transferase promotes influenza A virus-induced cytokine storm by targeting interferon regulatory factor-5

In this study, we demonstrated an essential function of the hexosamine biosynthesis pathway (HBP)-associated O-linked β-N-acetylglucosamine (O-GlcNAc) signaling in influenza A virus (IAV)-induced cytokine storm. O-GlcNAc transferase (OGT), a key enzyme for protein O-GlcNAcylation, mediated IAV-induced cytokine production. Upon investigating the mechanisms driving this event, we determined that IAV induced OGT to bind to interferon regulatory factor-5 (IRF5), leading to O-GlcNAcylation of IRF5 on serine-430. O-GlcNAcylation of IRF5 is required for K63-linked ubiquitination of IRF5 and subsequent cytokine production. Analysis of clinical samples revealed that IRF5 is O-GlcNAcylated, and higher levels of proinflammatory cytokines correlated with higher levels of blood glucose in IAV-infected patients. We identified a molecular mechanism by which HBP-mediated O-GlcNAcylation regulates IRF5 function during IAV infection, highlighting the importance of glucose metabolism in IAV-induced cytokine storm.

The double burden of diabetes and global infection in low and middle-income countries

Four out of five people in the world with diabetes now live in low- and middle-income countries (LMIC), and the incidence of diabetes is accelerating in poorer communities. Diabetes increases susceptibility to infection and worsens outcomes for some of the world’s major infectious diseases such as tuberculosis, melioidosis and dengue, but the relationship between diabetes and many neglected tropical diseases is yet to be accurately characterised. There is some evidence that chronic viral infections such as hepatitis B and HIV may predispose to the development of type 2 diabetes by chronic inflammatory and immunometabolic mechanisms. Helminth infections such as schistosomiasis may be protective against the development of diabetes, and this finding opens up new territory for discovery of novel therapeutics for the prevention and treatment of diabetes. A greater understanding of the impact of diabetes on risks and outcomes for infections causing significant diseases in LMIC is essential in order to develop vaccines and therapies for the growing number of people with diabetes at risk of infection, and to prioritise research agendas, public health interventions and policy. This review seeks to give an overview of the current international diabetes burden, the evidence for interactions between diabetes and infection, immune mechanisms for the interaction, and potential interventions to tackle the dual burden of diabetes and infection.

Higher frequency of hospitalization but lower relative mortality for pandemic influenza in people with type 2 diabetes

BACKGROUND

There is limited evidence linking type 2 diabetes (T2D) to influenza-related complications.

OBJECTIVES

To test a set of research questions relating to pandemic influenza vaccination, hospitalization and mortality in people with and without T2D.

METHODS

In this population-based cohort study, we linked individual-level data from several national registers for all Norwegian residents aged 30 years or more as of January 2009. People with or without T2D at baseline (n = 2 992 228) were followed until December 2013. We used Cox regression to estimate adjusted hazard ratios (aHRs).

RESULTS

Pandemic influenza hospitalization was more common in individuals with T2D (aHR = 2.46, 95% CI 2.04-2.98). The mortality hazard ratio associated with hospitalization for pandemic influenza was lower in people with T2D (aHR = 1.82, 95% CI 1.21-2.74) than in those without T2D (aHR = 3.89, 95% CI 3.27-4.62). The same pattern was observed when restricting to 90-day mortality (aHR = 3.89, 95% CI 1.25-12.06 amongst those with T2D and aHR = 10.79, 95% CI 7.23-16.10 amongst those without T2D). The rate of hospitalization for pandemic influenza was 78% lower in those vaccinated compared to nonvaccinated amongst people with T2D (aHR = 0.22, 95% CI 0.11-0.39), whilst the corresponding estimate for those without T2D was 59% lower (aHR = 0.41, 95% CI 0.33-0.52). Mortality was 25% lower in those vaccinated compared to nonvaccinated amongst people with T2D (aHR = 0.75, 95% CI 0.73-0.77), whilst the corresponding estimate for those without T2D was 9% (aHR = 0.91, 95% CI 0.90-0.92).

CONCLUSIONS

There may have been a lower threshold for pandemic influenza hospitalization for people with T2D, rather than more severe influenza infection. Our combined results support the importance of influenza vaccination amongst people with T2D, especially during pandemics.

Type 2 Diabetes: How Much of an Autoimmune Disease?

Type 2 diabetes (T2D) is characterized by a progressive status of chronic, low-grade inflammation (LGI) that accompanies the whole trajectory of the disease, from its inception to complication development. Accumulating evidence is disclosing a long list of possible "triggers" of inflammatory responses, many of which are promoted by unhealthy lifestyle choices and advanced age. Diabetic patients show an altered number and function of immune cells, of both innate and acquired immunity. Reactive autoantibodies against islet antigens can be detected in a subpopulation of patients, while emerging data are also suggesting an altered function of specific T lymphocyte populations, including T regulatory (Treg) cells. These observations led to the hypothesis that part of the inflammatory response mounting in T2D is attributable to an autoimmune phenomenon. Here, we review recent data supporting this framework, with a specific focus on both tissue resident and circulating Treg populations. We also propose that selective interception (or expansion) of T cell subsets could be an alternative avenue to dampen inappropriate inflammatory responses without compromising immune responses.

Antibodies in Melioidosis: The Role of the Indirect Hemagglutination Assay in Evaluating Patients and Exposed Populations

Melioidosis is a major neglected tropical disease with high mortality, caused by the Gram-negative bacterium Burkholderia pseudomallei (Bp). Microbiological culture remains the gold standard for diagnosis, but a simpler and more readily available test such as an antibody assay is highly desirable. In this study, we conducted a serological survey of blood donors (n = 1,060) and adult melioidosis patients (n = 200) in northeast Thailand to measure the antibody response to Bp using the indirect hemagglutination assay (IHA). We found that 38% of healthy adults (aged 17-59 years) have seropositivity (IHA titer ≥ 1:80). The seropositivity in healthy blood donors was associated with having a declared occupation of rice farmer and with residence in a nonurban area, but not with gender or age. In the melioidosis cohort, the seropositivity rate was higher in adult patients aged between 18 and 45 years (90%, 37/41) compared with those aged ≥ 45 years (68%, 108/159, P = 0.004). The seropositivity rate was significantly higher in people with diabetes (P = 0.008). Seropositivity was associated with decreased mortality on univariable analysis (P = 0.005), but not on multivariable analysis when adjusted for age, diabetes status, preexisting renal disease, and neutrophil count. This study confirms the presence of high background antibodies in an endemic region and demonstrates the limitations of using IHA during acute melioidosis in this population.

Immunogenicity, safety, and effectiveness of seasonal influenza vaccination in patients with diabetes mellitus: A systematic review

Influenza is associated with an increased risk of complications, especially in diabetic mellitus patients who are more susceptible to influenza infection. Despite recommendations of the WHO and public health authorities, vaccination uptake in this population remains suboptimal. This systematic review identified 15 studies published between January 2000-March 2017 in PubMed, Embase and Cochrane Library, which provided data on immunogenicity, safety, effectiveness, and/or cost-effectiveness of seasonal influenza vaccination in diabetic patients. Immunogenicity of seasonal influenza vaccination in diabetic patients was generally comparable to that of healthy participants. One month after vaccination of diabetic patients, seroconversion rates and seroprotection ranged from 24.0-58.0% and 29.0-99.0%, respectively. Seasonal influenza vaccination reduced the risk of hospitalization and mortality in diabetic patients, particularly those aged ≥65 years. These review results demonstrate and reinforce the need and value of annual influenza vaccination in diabetic patients, particularly in alleviating severe complications such as hospitalization or death.

2015/16 seasonal vaccine effectiveness against hospitalisation with influenza A(H1N1)pdm09 and B among elderly people in Europe: results from the I-MOVE+ project

We conducted a multicentre test-negative case-control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged ≥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases.

Aging, cytomegalovirus (CMV) and influenza vaccine responses

Influenza vaccination is less effective in elderly as compared to young individuals. Several studies have identified immune biomarkers able to predict a protective humoral immune response to the vaccine. In this review, we summarize current knowledge on the effects of aging on influenza vaccine responses and on biomarkers so far identified, and we discuss the relevance of latent cytomegalovirus (CMV) infection on these vaccine responses.

Effectiveness of seasonal influenza vaccination in patients with diabetes: protocol for a nested case-control study

INTRODUCTION

Seasonal influenza vaccination (SIV) is recommended for people with diabetes, but its effectiveness has not been demonstrated. All of the available studies are observational and marred with the healthy vaccine bias, that is, bias resulting from the generally better health behaviours practised by people who choose to be vaccinated against influenza, compared with those who do not. This protocol is intended to study the effectiveness of SIV in people with treated diabetes and simultaneously to control for bias.

METHODS AND ANALYSES

This case-control study is nested in a historical cohort and is designed to study vaccine effectiveness (VE) assessed by morbidity, mortality and anti-infective drug use. The cohort will comprise a representative sample of health insurance beneficiaries in France and will cover 10 consecutive epidemic seasons. It will include all patients reimbursed three separate times for drugs to treat diabetes. The first study of VE will use reasons for hospitalisation as the primary end point, and the second with the use of neuraminidase inhibitors and of antibiotics as the end points. A case will be defined as any person in the cohort reaching any end point at a given date. The case patient will be matched with the largest possible number of controls (individuals not reaching the end point by this date) according to the propensity score method with an optimal calliper width. A conditional logistic model will be used to estimate ORs to take into account both the matching and the repetition of measurements. The model will be applied separately during and outside of epidemic periods to estimate the residual confounding.

ETHICS AND DISSEMINATION

The study has been approved by the French Commission on Individual Data Protection and Public Liberties (ref: AT/CPZ/SVT/JB/DP/CR05222O). The study's findings will be published in peer-reviewed journals and disseminated at international conferences and through social media.

Benefits of flu vaccination for persons with diabetes mellitus: A review

Diabetes mellitus imposes a significant and increasing burden on society, with major consequences for human health, welfare and the economy worldwide. Persons with diabetes mellitus are at increased risk of developing severe complications after influenza virus infection and guidelines advise vaccination. The present evidence for influenza vaccine effectiveness in persons with diabetes mellitus is mainly based on observational studies with clinical endpoints like hospitalization and death, indicating a beneficial reduction of morbidity and mortality. Further supportive evidence comes from serological studies, in which persons with diabetes mellitus usually develop similar antibody levels after vaccination as healthy people. Observational studies may be prone to selection bias, and serological studies may not completely mirror vaccine effectiveness in the field. Although more controlled trials in persons with diabetes mellitus with laboratory-confirmed, influenza-specific outcomes would be desirable to better estimate the effect of vaccination, the currently available data justify routine influenza vaccination in persons with diabetes mellitus. As in this risk group, the use of influenza vaccine is far below target worldwide, efforts should be made to increase vaccination coverage.

Metformin improves in vivo and in vitro B cell function in individuals with obesity and Type-2 Diabetes

Metformin (MET), the first-line medication for Type-2 Diabetes (T2D), has been shown to reduce chronic inflammation indirectly through reduction of hyperglycemia, or directly acting as anti-inflammatory drug. The effects of MET on B lymphocytes is uncharacterized. In the present study, we measured in vivo and in vitro influenza vaccine responses in 2 groups of T2D patients: recently diagnosed but not taking anti-diabetic drugs, and patients taking MET. Results show that B cell function and vaccine responses, hampered by obesity and T2D, are recovered by MET. Moreover, MET used in vitro to stimulate B cells from recently diagnosed T2D patients is also able to reduce B cell-intrinsic inflammation and increase antibody responses, similar to what we have seen in B cells from patients taking MET, who show increased responses to the influenza vaccine in vivo. These results are the first to show an effect of MET on B cells.

Influences of obesity on the immunogenicity of Hepatitis B vaccine

OBJECTIVE

Hepatitis B vaccine is regarded as the most effective method for the prevention of hepatitis B virus (HBV) infection. However, several factors such as age, body mass index and immunocompetent state have been reported to be associated with reduced immunization responses. The present commentary was aimed to discuss the influences of obesity on the immunogenicity of hepatitis B vaccines.

DATA SOURCES

Available peer-reviewed literatures, practice guidelines, and statistics published on hepatitis B vaccine in obesity between 1973 and 2015.

CONCLUSIONS

Obesity was significantly associated with non-response to hepatitis B vaccine immunization. The risk of nonresponsiveness of hepatitis B vaccine among obese people increased with BMI. Moreover, the obesity might lead to an increased risk of HBV vaccine-escape mutations. The mechanism responsible for decreased immunization responses in obesity included leptin-induced systemic and B cell intrinsic inflammation, impaired T cell responses and lymphocyte division and proliferation. Therefore, more studies should be performed to analyze the influences of obesity on the immunogenicity of hepatitis B vaccines to improve the immunoprotecive effect of hepatitis B vaccines in future.

The generation of memory B cells is maintained, but the antibody response is not, in the elderly after repeated influenza immunizations

The success of a vaccine in inducing a protective antibody response depends on the longevity of both long-lived plasma cells (PC) and memory B cells. We have previously shown that the in vivo antibody response to a new influenza vaccine, the ex vivo plasmablast response, the in vitro B cell function, measured by AID (activation-induced cytidine deaminase), and the transcription factor E47, are significantly associated and decreased in elderly individuals. We hypothesized that because AID is decreased in the elderly, the ability to generate memory B cells would also be decreased, but our findings here show that memory B cells are maintained in the elderly probably due to further amplification in response to repeated vaccination. We recruited young and elderly individuals immunized in at least two consecutive influenza vaccine seasons in which the influenza A viral strains H1N1 and H3N2 in the vaccine were the same as in the previous year. PBMC were cultured with CpG/IL2 to measure the frequency of IgG vaccine-specific memory B cells. Serum antibody response was measured by hemagglutination inhibition assay. Blood plasmablasts were measured by flow cytometry. Surprisingly, the frequencies of influenza vaccine-specific memory B cells and plasmablasts were similar in young and elderly individuals, but the fold-increase in serum titers after vaccination was lower in the elderly although most of the elderly were seroprotected. We then measured the transcription factor Blimp-1, considered the master regulator of PC differentiation, and found it significantly reduced in cultures of B cells from elderly versus young individuals, as well as E47/AID and IgG secretion. Taken together, these results suggest an impaired memory B cell to PC differentiation in the elderly.