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95 result(s) for "McElhaney, Janet E."
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Age and frailty in COVID-19 vaccine development
Immune responses were measured using assays of anti-spike protein IgG and neutralising antibody titres for humoral immunity and IFN-γ enzyme-linked immunospot (ELISpot) for cell-mediated immunity. In IFN-γ ELISpot assays enumerating antigen-specific T cells done for those in the prime-boost standard-dose group, T-cell responses peaked at 14 days after a single standard dose and did not increase significantly after a boost dose (18–55 years, median 1187 spot forming cells [SFCs] per million peripheral blood mononuclear cells [IQR 841–2428], n=24; 56–69 years, 797 SFCs [383–1817], n=29; and ≥70 years 977 SFCs [458–1914], n=48; p=0·46). The inclusion of measures of cell-mediated immunity is important given the limitations of relying solely on antibody titres in older adults.4,5 The main study limitations were its single-blind design, the inclusion of few participants older than 80 years, and exclusion of people with substantial underlying chronic illnesses and frailty.
Efficacy of an Adjuvanted Herpes Zoster Subunit Vaccine in Older Adults
In this randomized, controlled trial involving more than 15,000 participants 50 years of age or older, a varicella–zoster virus subunit vaccine with AS01B adjuvant was found to have an efficacy of more than 96% in preventing herpes zoster. Herpes zoster, or shingles, results from the reactivation of latent varicella–zoster virus (VZV) in the dorsal-root or cranial-nerve ganglia, usually decades after primary infection. 1 , 2 Herpes zoster is characterized by a vesicular rash with a unilateral and dermatomal distribution and is almost always accompanied by pain. More than 90% of adults have been infected with VZV and are at risk for herpes zoster. 3 , 4 Although herpes zoster is most frequent in adults who are 50 years of age or older owing to immunosenescence, it can occur at any age, especially when cell-mediated immunity is decreased as a result of disease . . .
The Importance of Frailty in the Assessment of Influenza Vaccine Effectiveness Against Influenza-Related Hospitalization in Elderly People
Background. Influenza is an important cause of morbidity and mortality among older adults. Even so, effectiveness of influenza vaccine for older adults has been reported to be lower than for younger adults, and the impact of frailty on vaccine effectiveness (VE) and outcomes is uncertain. We aimed to study VE against influenza hospitalization in older adults, focusing on the impact of frailty. Methods. We report VE of trivalent influenza vaccine (TIV) in people ≥65 years of age hospitalized during the 2011–2012 influenza season using a multicenter, prospective, test-negative case-control design. A validated frailty index (FI) was used to measure frailty. Results. Three hundred twenty cases and 564 controls (mean age, 80.6 and 78.7 years, respectively) were enrolled. Cases had higher baseline frailty than controls (P = .006). In the fully adjusted model, VE against influenza hospitalization was 58.0% (95% confidence interval [CI], 34.2%–73.2%). The contribution of frailty was important; adjusting for frailty alone yielded a VE estimate of 58.7% (95% CI, 36.2%–73.2%). VE was 77.6% among nonfrail older adults and declined as frailty increased. Conclusions. Despite commonly held views that VE is poor in older adults, we found that TIV provided good protection against influenza hospitalization in older adults who were not frail, though VE diminished as frailty increased.
Immune Responses to a Recombinant Glycoprotein E Herpes Zoster Vaccine in Adults Aged 50 Years or Older
Abstract Background The herpes zoster subunit vaccine (HZ/su), consisting of varicella-zoster virus glycoprotein E (gE) and AS01B Adjuvant System, was highly efficacious in preventing herpes zoster in the ZOE-50 and ZOE-70 trials. We present immunogenicity results from those trials. Methods Participants (ZOE-50: ≥50; ZOE-70: ≥70 years of age) received 2 doses of HZ/su or placebo, 2 months apart. Serum anti-gE antibodies and CD4 T cells expressing ≥2 of 4 activation markers assessed (CD42+) after stimulation with gE-peptides were measured in subcohorts for humoral (n = 3293) and cell-mediated (n = 466) immunogenicity. Results After vaccination, 97.8% of HZ/su and 2.0% of placebo recipients showed a humoral response. Geometric mean anti-gE antibody concentrations increased 39.1-fold and 8.3-fold over baseline in HZ/su recipients at 1 and 36 months post-dose 2, respectively. A gE-specific CD42+ T-cell response was shown in 93.3% of HZ/su and 0% of placebo recipients. Median CD42+ T-cell frequencies increased 24.6-fold (1 month) and 7.9-fold (36 months) over baseline in HZ/su recipients and remained ≥5.6-fold above baseline in all age groups at 36 months. The proportion of CD4 T cells expressing all 4 activation markers increased over time in all age groups. Conclusions Most HZ/su recipients developed robust immune responses persisting for 3 years following vaccination. Clinical Trials Registration NCT01165177; NCT01165229. The herpes zoster subunit vaccine, consisting of varicella-zoster virus glycoprotein E and the AS01B Adjuvant System, stimulated specific antibody and CD4 T-cell responses in >90% of recipients which, in most, persisted for the 36-month duration of the study.
The immune response to influenza in older humans: beyond immune senescence
Despite widespread influenza vaccination programs, influenza remains a major cause of morbidity and mortality in older adults. Age-related changes in multiple aspects of the adaptive immune response to influenza have been well-documented including a decline in antibody responses to influenza vaccination and changes in the cell-mediated response associated with immune senescence. This review will focus on T cell responses to influenza and influenza vaccination in older adults, and how increasing frailty or coexistence of multiple (≥2) chronic conditions contributes to the loss of vaccine effectiveness for the prevention of hospitalization. Further, dysregulation of the production of pro- and anti-inflammatory mediators contributes to a decline in the generation of an effective CD8 T cell response needed to clear influenza virus from the lungs. Current influenza vaccines provide only a weak stimulus to this arm of the adaptive immune response and rely on re-stimulation of CD8 T cell memory related to prior exposure to influenza virus. Efforts to improve vaccine effectiveness in older adults will be fruitless until CD8 responses take center stage.
Effectiveness of a nurse-led hospital-to-home transitional care intervention for older adults with multimorbidity and depressive symptoms: A pragmatic randomized controlled trial
To evaluate the effectiveness of a nurse-led hospital-to-home transitional care intervention versus usual care on mental functioning (primary outcome), physical functioning, depressive symptoms, anxiety, perceived social support, patient experience, and health service use costs in older adults with multimorbidity ([greater than or equal to] 2 comorbidities) and depressive symptoms. Pragmatic multi-site randomized controlled trial conducted in three communities in Ontario, Canada. Participants were allocated into two groups of intervention and usual care (control). 127 older adults ([greater than or equal to] 65 years) discharged from hospital to the community with multimorbidity and depressive symptoms. This evidence-based, patient-centred intervention consisted of individually tailored care delivery by a Registered Nurse comprising in-home visits, telephone follow-up and system navigation support over 6-months. The primary outcome was the change in mental functioning, from baseline to 6-months. Secondary outcomes were the change in physical functioning, depressive symptoms, anxiety, perceived social support, patient experience, and health service use cost, from baseline to 6-months. Intention-to-treat analysis was performed using ANCOVA modeling. Of 127 enrolled participants (63-intervention, 64-control), 85% had six or more chronic conditions. 28 participants were lost to follow-up, leaving 99 (47 -intervention, 52-control) participants for the complete case analysis. No significant group differences were seen for the baseline to six-month change in mental functioning or other secondary outcomes. Older adults in the intervention group reported receiving more information about health and social services (p = 0.03) compared with the usual care group. Although no significant group differences were seen for the primary or secondary outcomes, the intervention resulted in improvements in one aspect of patient experience (information about health and social services). The study sample fell below the target sample (enrolled 127, targeted 216), which can account for the non-significant findings. Further research on the impact of the intervention and factors that contribute to the results is recommended.
Impact of Aging and Cytomegalovirus on Immunological Response to Influenza Vaccination and Infection
The number of people over the age of 60 is expected to double by 2050 according to the WHO. This emphasizes the need to ensure optimized resilience to health stressors in late life. In older adults, influenza is one of the leading causes of catastrophic disability (defined as the loss of independence in daily living and self-care activities). Influenza vaccination is generally perceived to be less protective in older adults, with some studies suggesting that the humoral immune response to the vaccine is further impaired in cytomegalovirus (CMV)-seropositive older people. CMV is a β-herpes virus infection that is generally asymptomatic in healthy individuals. The majority of older adults possess serum antibodies against the virus indicating latent infection. Age-related changes in T-cell-mediated immunity are augmented by CMV infection and may be associated with more serious complications of influenza infection. This review focuses on the impact of aging and CMV on immune cell function, the response to influenza infection and vaccination, and how the current understanding of aging and CMV can be used to design a more effective influenza vaccine for older adults. It is anticipated that efforts in this field will address the public health need for improved protection against influenza in older adults, particularly with regard to the serious complications leading to loss of independence.
T-Cell Immunity to Influenza in Older Adults: A Pathophysiological Framework for Development of More Effective Vaccines
One of the most profound public health consequences of immune senescence is reflected in an increased susceptibility to influenza and other acute respiratory illnesses, as well as a loss of influenza vaccine effectiveness in older people. Common medical conditions and mental and psychosocial health issues as well as degree of frailty and functional dependence accelerate changes associated with immune senescence. All contribute to the increased risk for complications of influenza infection, including pneumonias, heart diseases, and strokes that lead to hospitalization, disability, and death in the over 65 population. Changes in mucosal barrier mechanisms and both innate and adaptive immune functions converge in the reduced response to influenza infection, and lead to a loss of antibody-mediated protection against influenza with age. The interactions of immune senescence and reduced adaptive immune responses, persistent cytomegalovirus infection, inflammaging (chronic elevation of inflammatory cytokines), and dysregulated cytokine production, pose major challenges to the development of vaccines designed to improve T-cell-mediated immunity. In older adults, the goal of vaccination is more realistically targeted to providing clinical protection against disease rather than to inducing sterilizing immunity to infection. Standard assays of antibody titers correlate with protection against influenza illness but do not detect important changes in cellular immune mechanisms that correlate with vaccine-mediated protection against influenza in older people. This article will discuss: (i) the burden of influenza in older adults and how this relates to changes in T-cell function, (ii) age-related changes in different T-cell subsets and immunologic targets for improved influenza vaccine efficacy in older, and (iii) the development of correlates of clinical protection against influenza disease to expedite the process of new vaccine development for the 65 and older population. Ultimately, these efforts will address the public health need for improved protection against influenza in older adults and \"vaccine preventable disability.\"
The unmet need in the elderly: How immunosenescence, CMV infection, co-morbidities and frailty are a challenge for the development of more effective influenza vaccines
► As part of the “inflammaging” process, innate immune processes may not only be ineffective, they may result in harmful inflammatory responses to infection. ► Increased levels of “bGrzB” activity associated with CMV, may be a common thread between immune dysfunction and the risk for cardiovascular complications of influenza. ► The IFN-γ:IL-10 ratio and GrzB activity in influenza-challenged PBMC can be used as biomarkers to firmly establish vaccine-mediated protection/failure. ► Adding specific adjuvants may further enhance vaccine responses even in the face of a suboptimal immune system. ► Reliance on antibody titers as a sole predictor of vaccine efficacy is a major barrier to the development of more effective influenza vaccines, which remains an unmet need. Influenza remains the single most important cause of excess disability and mortality during the winter months. In spite of widespread influenza vaccination programs leading to demonstrated cost-savings in the over 65 population, hospitalization and death rates for acute respiratory illnesses continue to rise. As a person ages, increased serum levels of inflammatory cytokines are commonly recorded (TNF-α, IL-1, IL-6). Termed “inflammaging”, this has been linked to persistent cytomegalovirus (CMV) infection and immune senescence, while increased anti-inflammatory cytokines (IL-10, TGF-β) are possibly associated with more healthy aging. Paradoxically, a shift with aging toward an anti-inflammatory (IL-10) response and decline in the IFN-γ:IL-10 ratio in influenza-challenged peripheral blood mononuclear cells is associated with a decline in the cytolytic capacity of CD8+ T cells responsible for clearing influenza virus from infected lung tissue. Thus, it is seemingly counter intuitive that the immune phenotype of healthy aging predicts a poor cell-mediated immune response and more serious outcomes of influenza. Herein we postulate a mechanistic link between the accumulation of late-stage, potentially terminally differentiated T cells, many or most of which result from CMV infection, and the immunopathogenesis of influenza infection, mediated by granzyme B in older adults. Further, adjuvanted influenza vaccines that stimulate inflammatory cytokines and suppress the IL-10 response to influenza challenge, would be expected to enhance protection in the 65+ population.
Reliable reference genes for the quantification of mRNA in human T-cells and PBMCs stimulated with live influenza virus
Background Quantitative PCR (qPCR) is a powerful tool that is particularly well-suited to measure mRNA levels in clinical samples, especially those with relatively low cell counts. However, a caveat of this approach is that reliable, stably expressed reference (housekeeping) genes are vital in order to ensure reproducibility and appropriate biological inference. In this study, we evaluated the expression stability of six reference genes in peripheral blood mononuclear cells (PBMCs) and isolated CD3 + T-cells from young and old adults ( n  = 10), following ex vivo stimulation with mock (unstimulated) or live influenza virus. Our genes included: β-actin ( ACTB ), glyercaldehyde-3-phostphate dehydrogenase ( GAPDH ), ribosomal protein L13a ( RPL13a ), ribosomal protein S18 ( RPS18 ), succinate dehydrogenase complex flavoprotein subunit A ( SDHA ), and ubiquitin-conjugating enzyme E2D2 ( UBE2D2 ). Results Reference gene expression varied significantly depending on cell type and stimulation conditions, but not age. Using the comparative ΔCt method, and the previously published software BestKeeper, NormFinder, and geNorm, we show that in PBMCs and T-cells, UBE2D2 and RPS18 were the most stable reference genes, followed by ACTB ; however, the expression of UBE2D2 and RPS18 was found to increase with viral stimulation in isolated T-cells, while ACTB expression did not change significantly. No age-related differences in stability were observed for any gene Conclusions This study suggests the use of a combination of UBE2D2 , RPS18 , and ACTB for the study of influenza responses in PBMCs and T-cells, although ACTB alone may be the most optimal choice if choosing to compare target gene expression before and after viral stimulation. Both GAPDH and RPL13a were found to be poor reference genes and should be avoided for studies of this nature.