Immune response of 23-valent pneumococcal polysaccharide vaccinated elderly and its relation to frailty indices, nutritional status, and serum zinc levels

Rebalancing the unbalanced aged immune system - A special focus on zinc

Nowadays, aging is understood as a dynamic and multifaceted dysregulation process that spares almost no human organ or cell. The immune system being among the most affected, it has been shown predominantly that its integrity determines the tightrope walk between the difference of escaping or suffering from age-related diseases. Next to drug-based anti-aging strategies, micronutrient intervention may represent an emerging but less radical way to slow immune aging. While a sufficient supply of a variety of micronutrients is undeniably important, adequate intake of the trace element zinc appears to tower over others in terms of reaching old age. Inconveniently, zinc deficiency prevalence among the elderly is high, which in turn contributes to increased susceptibility to infection, decreased anti-tumor immunity as well as attenuated response to vaccination. Driven by this research, this review aims to provide a comprehensive and up-to-date overview of the various rebalancing capabilities of zinc in the unbalanced immune system of the elderly. This includes an in-depth and cell type-centered discussion on the role of zinc in immunosenescence and inflammaging. We further address upcoming translational aspects e.g. how zinc deficiency promotes the flourishing of certain pathogenic taxa of the gut microbiome and how zinc supply counteracts such alterations in a manner that may contribute to longevity. In the light of the ongoing COVID-19 pandemic, we also briefly review current knowledge on the interdependency between age, zinc status, and respiratory infections. Based on two concrete examples and considering the latest findings in the field we conclude our remarks by outlining tremendous parallels between suboptimal zinc status and accelerated aging on the one hand and an optimized zinc status and successful aging on the other hand.

Fostering healthy aging: The interdependency of infections, immunity and frailty

Untangling the interdependency of infections, immunity and frailty may help to clarify their roles in the maintenance of health in aging individuals, and the recent COVID-19 pandemic has further highlighted such priority. In this scoping review we aimed to systematically collect the evidence on 1) the impact of common infections such as influenza, pneumonia and varicella zoster on frailty development, and 2) the role played by frailty in the response to immunization of older adults. Findings are discussed under a unifying framework to identify knowledge gaps and outline their clinical and public health implications to foster a healthier aging. Twenty-nine studies (113,863 participants) selected to answer the first question provided a moderately strong evidence of an association between infections and physical as well as cognitive decline - two essential dimensions of frailty. Thirteen studies (34,520 participants) investigating the second aim, showed that frailty was associated with an impaired immune response in older ages, likely due to immunosenescence. However, the paucity of studies, the absence of tools to predict vaccine efficacy, and the lack of studies investigating the efficacy of newer vaccines in presence of frailty, strongly limit the formulation of more personalized immunization strategies for older adults. The current evidence suggests that infections and frailty repeatedly cross each other pathophysiological paths and accelerate the aging process in a vicious circle. Such evidence opens to several considerations. First, the prevention of both conditions pass through a life course approach, which includes several individual and societal aspects. Second, the maintenance of a well-functioning immune system may be accomplished by preventing frailty, and vice versa. Third, increasing the adherence to immunization may delay the onset of frailty and maintain the immune system homeostasis, beyond preventing infections.

Zinc and respiratory tract infections: Perspectives for COVID‑19 (Review)

In view of the emerging COVID‑19 pandemic caused by SARS‑CoV‑2 virus, the search for potential protective and therapeutic antiviral strategies is of particular and urgent interest. Zinc is known to modulate antiviral and antibacterial immunity and regulate inflammatory response. Despite the lack of clinical data, certain indications suggest that modulation of zinc status may be beneficial in COVID‑19. In vitro experiments demonstrate that Zn2+ possesses antiviral activity through inhibition of SARS‑CoV RNA polymerase. This effect may underlie therapeutic efficiency of chloroquine known to act as zinc ionophore. Indirect evidence also indicates that Zn2+ may decrease the activity of angiotensin‑converting enzyme 2 (ACE2), known to be the receptor for SARS‑CoV‑2. Improved antiviral immunity by zinc may also occur through up‑regulation of interferon α production and increasing its antiviral activity. Zinc possesses anti‑inflammatory activity by inhibiting NF‑κB signaling and modulation of regulatory T‑cell functions that may limit the cytokine storm in COVID‑19. Improved Zn status may also reduce the risk of bacterial co‑infection by improving mucociliary clearance and barrier function of the respiratory epithelium, as well as direct antibacterial effects against S. pneumoniae. Zinc status is also tightly associated with risk factors for severe COVID‑19 including ageing, immune deficiency, obesity, diabetes, and atherosclerosis, since these are known risk groups for zinc deficiency. Therefore, Zn may possess protective effect as preventive and adjuvant therapy of COVID‑19 through reducing inflammation, improvement of mucociliary clearance, prevention of ventilator‑induced lung injury, modulation of antiviral and antibacterial immunity. However, further clinical and experimental studies are required.

The SENIEUR protocol and the efficacy of hepatitis B vaccination in healthy elderly persons by age, gender, and vaccine route

BACKGROUND

Reduced response to hepatitis B vaccines is associated with aging, confounding and comorbid conditions, as well as inadvertent subcutaneous (SC) inoculation. We hypothesized that the antibody and T cell-mediated immune responses (T-CMI) of elderly adults to a vaccine intended for intramuscular (IM) administration would be attenuated when deposited into SC fat, independent of confounding conditions.

RESULTS

Fifty-two healthy, community dwelling elderly adults (65-82 years), seronegative for HBV, were enrolled in the SENIEUR protocol as a strictly healthy population. These seniors were randomized to receive a licensed alum-adjuvanted recombinant HBV vaccine either SC or IM, with the inoculum site verified by imaging. The response rates, defined as hepatitis B surface antibodies (HBsAb) ≥10 IU/L, were significantly lower in the elderly than in young adults, a group of 12, healthy, 21-34-year-old volunteers. Moreover, elderly participants who received the vaccine IM were significantly more likely to be responders than those immunized SC (54% versus 16%, p = 0.008). The low seroconversion rate in the IM group progressively declined with increasing age, and responders had significantly lower HBsAb titers and limited isotype responses. Moreover, T-CMI (proliferation and cytokine production) were significantly reduced in both percentage of responders and intensity of the response for both Th1 and Th2 subsets in the elderly.

CONCLUSIONS

Our data demonstrate the blunted immunogenicity of SC inoculation as measured by peak titers and response rates. Further, the qualitative and quantitative deficits in B- and T-CMI responses to primary alum adjuvanted protein antigens persisted even in strictly healthy elderly populations with verified IM placement compared to younger populations.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT04162223. Registered 14 November 2019. Retrospectively registered.

[Vaccination in advanced age]

Infectious diseases are responsible for up to 5% of fatalities even in developed countries. In addition, there is an increasing susceptibility for infections in elderly people due to physiological aging of the immune system. The principles of vaccination are based on a targeted activation of the human immune system. Principally, a distinction is made between passive immunization, i.e. the application of specific antibodies against a pathogen and active immunization. In active immunization, i.e. vaccination, weakened (attenuated) or dead pathogens or components of pathogens (antigens) are administered. After a latency period that depends on the vaccine, complete immune protection is achieved and immunity is maintained for a certain period of time. In contrast to dead vaccines, by the use of live vaccines there is always a risk for infection with the administered vaccine. In passive immunization antibodies are administered. As a rule passive immunization is carried out in persons who have had contact with an infected person and in whom no or uncertain immunity against the corresponding disease is present. Based on the recommendations of the Standing Committee on Vaccination (STIKO), influenza, pneumococcal, herpes zoster, early summer meningoencephalitis (FSME) and travel vaccines are described.

Pneumococcal Vaccination Guidance for Post-Acute and Long-Term Care Settings: Recommendations From AMDA's Infection Advisory Committee

Efforts at preventing pneumococcal disease are a national health priority, particularly in older adults and especially in post-acute and long-term care settings The Advisory Committee on Immunization Practices recommends that all adults ≥65 years of age, as well as adults 18-64 years of age with specific risk factors, receive both the recently introduced polysaccharide-protein conjugate vaccine against 13 pneumococcal serotypes as well as the polysaccharide vaccine against 23 pneumococcal serotypes. Nursing facility licensure regulations require facilities to assess the pneumococcal vaccination status of each resident, provide education regarding pneumococcal vaccination, and administer the appropriate pneumococcal vaccine when indicated. Sorting out the indications and timing for 13 pneumococcal serotypes and 23 pneumococcal serotypes administration is complex and presents a significant challenge to healthcare providers. Here, we discuss the importance of pneumococcal vaccination for older adults, detail AMDA-The Society for Post-Acute and Long-Term Care Medicine (The Society)'s recommendations for pneumococcal vaccination practice and procedures, and offer guidance to postacute and long-term care providers supporting the development and effective implementation of pneumococcal vaccine policies.

High Prevalence of Physical Frailty Among Community-Dwelling Malnourished Older Adults-A Systematic Review and Meta-Analysis

BACKGROUND

Malnutrition and frailty are two geriatric syndromes that significantly affect independent living and health in community-dwelling older adults. Although the pathophysiology of malnutrition and physical frailty share common pathways, it is unknown to what extent these syndromes overlap and how they relate to each other.

METHODS

A systematic review was performed resulting in a selection of 28 studies that assessed both malnutrition and frailty in community-dwelling older adults. Furthermore, a meta-analysis was performed on 10 studies that used Mini- Nutritional Assessment and the Fried frailty phenotype to estimate the prevalence of malnutrition within physical frailty and vice versa.

RESULTS

In the systematic review, 25 of the 28 studies used the Mini-Nutritional Assessment (long or short form) for malnutrition screening. For frailty assessment, 23 of the 28 studies focused on the physical frailty phenotype, of which 19 followed the original Fried phenotype. Fifteen studies analyzed the association between malnutrition and frailty, which was significant in 12 of these. The meta-analysis included 10 studies with a total of 5447 older adults. In this pooled population of community-dwelling older adults [mean (standard deviation) age: 77.2 (6.7) years], 2.3% was characterized as malnourished and 19.1% as physically frail. The prevalence of malnutrition was significantly associated with the prevalence of physical frailty (P < .0001). However, the syndromes were not interchangeable: 68% of the malnourished older adults was physically frail, whereas only 8.4% of the physical frail population was malnourished.

CONCLUSIONS

The systematic review and meta-analysis revealed that malnutrition and physical frailty in community-dwelling older adults are related, but not interchangeable geriatric syndromes. Two out of 3 malnourished older adults were physically frail, whereas close to 10% of the physically frail older adults was identified as malnourished.

[Pneumococcal vaccination for prevention of pneumonia]

Aging of the immune system, so-called immunosenescence, is well documented as the cause of increased infection rates and severe, often complicated courses of infections in older adults. This is particularly true for pneumococcal pneumonia in older adults; therefore, the standing committee on vaccination of the Robert Koch Institute (STIKO) recommends a once only vaccination with 23-valent pneumococcal polysaccharide vaccine for all persons aged 60 years and over. Furthermore, the 13-valent pneumococcal conjugate vaccine is also available for administration in adults and is recommended by the STIKO for particular indications. The advantage of the pneumococcal conjugate vaccine is the additional induction of a T-cell dependent immune response that leads to good immunogenicity despite immunosenescence. Initial data from a recent randomized controlled trial, so far only presented at conferences, confirm that the conjugate vaccine also provides protection against non-bacteremic pneumococcal pneumonia, which is not provided by the polysaccharide vaccine. Thus, there are two vaccines for prevention of pneumococcal diseases: one with a broader range of serotype coverage but with an uncertain protection against non-bacteremic pneumococcal pneumonia and another one with less serotype coverage but more effective protection. Vaccination of children with the conjugate vaccine also leads to a rapid decrease of infections by the 13 vaccine serotypes even in adults because of herd protection effects. For prevention of pneumonia in older adults the additional benefit of a concurrent application of influenza vaccine and pneumococcal vaccine should be considered.

Vaccination in the elderly: what can be recommended?

The age-associated increased susceptibility to infectious disease would suggest that vaccination should be a route to promote healthy aging and keep our seniors autonomous and independent. While vaccination represents a cost-effective and efficient strategy at community level, the ability of the immune system to mount a protective immune response is still unpredictable at the level of the individual. Thus, at a similar age, some individuals, including the elderly, might still be 'good' responders while some other, even younger, would definitely fail to mount a protective response. In this review, the current burden of vaccine-preventable diseases in the aging and aged population will be detailed with the aim to identify the ideal vaccine candidates over the age of 50 years. This article will conclude with potential strategies to reduce, as best as possible, this burden and the imperative need to overcome barriers in extending current vaccine coverage towards to a lifelong vaccine schedule.

Zinc, aging, and immunosenescence: an overview

Zinc plays an essential role in many biochemical pathways and participates in several cell functions, including the immune response. This review describes the role of zinc in human health, aging, and immunosenescence. Zinc deficiency is frequent in the elderly and leads to changes similar to those that occur in oxidative inflammatory aging (oxi-inflamm-aging) and immunosenescence. The possible benefits of zinc supplementation to enhance immune function are discussed.

Phase II trial of a GM-CSF-producing and CD40L-expressing bystander cell line combined with an allogeneic tumor cell-based vaccine for refractory lung adenocarcinoma

We created a vaccine in which irradiated allogeneic lung adenocarcinoma cells are combined with a bystander K562 cell line transfected with hCD40L and hGM-CSF. By recruiting and activating dendritic cells, we hypothesized that the vaccine would induce tumor regression in metastatic lung adenocarcinoma. Intradermal vaccine was given q14 days×3, followed by monthly ×3. Cyclophosphamide (300 mg/m IV) was administered before the first and fourth vaccines to deplete regulatory T cells. All-trans retinoic acid was given (150/mg/m/d) after the first and fourth vaccines to enhance dendritic cell differentiation. Twenty-four participants were accrued at a single institution from October 2006 to June 2008, with a median age 64 years and median of 4 previous lines of systemic therapy. A total of 101 vaccines were administered. Common toxicities were headache (54%) and site reaction (38%). No radiologic responses were observed. Median overall survival was 7.9 months and median progression-free survival was 1.7 months. Of 14 patients evaluable for immunological study, 5 had peptide-induced CD8 T-cell activation after vaccination. Overall, vaccine administration was feasible in an extensively pretreated population of metastatic lung cancer. Despite a suggestion of clinical activity in the subset with immune response, the trial did not meet the primary endpoint of inducing radiologic tumor regression.