Immunological responses to pneumococcal vaccine in frail older people

Commentary on: Cost-effectiveness of pneumococcal vaccination and of programs to increase its uptake in U.S. older adults

See related articles by Wateska et al.

Frailty in clinical drug trials: Frailty assessments, subgroup analyses and outcomes

With population ageing, drug trials are increasingly turning their attention to including older, frailer people. This review aimed to provide an overview of how frailty was assessed in published studies related to clinical pharmacological trials, and on the interaction of frailty on the efficacy of the treatments. We searched MEDLINE, EMBASE and Cochrane for clinical drug trials in older people. A total of 4031 abstracts were screened and 17 relevant studies were included in this review. We summarized the findings of these 17 trials into five main clinical areas: cardiovascular (eight studies), cognition (one study), vaccination (two studies), cancer (four studies) and other (two studies). Frailty was assessed retrospectively in most of the studies. Frailty was treated as an ordinal variable (with different levels of frailty) or binary variable (frail/non-frail) using cut-offs in some studies, and as a continuous in some other studies. The effect of frailty on the treatment efficacy was not consistent among the studies. While several trials, such as the Action in Diabetes and Vascular Disease-Preterax and Diamicron Modified Release Controlled Evaluation trials, the Systolic Blood Pressure Intervention Trial and the Aspirin in Reducing Events in the Elderly trial, showed some reduced effects of the treatment in frail patients, most of the trials showed that the benefits of the treatment are not affected by frailty. Some trials even showed that the benefits of the treatment were more significant in frailer patients (the Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure and the Dapagliflozin Evaluation to Improve the Lives of Patients with Preserved Ejection Fraction Heart Failure trials). The results of this review suggest that routine measurement of frailty in participants in clinical drug trials would improve our knowledge of the effect of treatment in the frail and identify those who have more or least to gain from treatment.

Baseline Pneumococcal IgG Levels and Response to 23-Valent Pneumococcal Polysaccharide Vaccine among Adults from Beijing, China

PURPOSE

To investigate the baseline levels of serotype-specific IgG antibodies to Streptococcus pneumoniae (S. pneumoniae) and assess their impact on the assessment of vaccine immunogenicity.

METHODS

We used a subset of serum samples from a randomized controlled trial. The blood of 584 healthy participants was collected on day 0 before and day 28 after the 23-valent pneumococcal polysaccharide vaccine (PPSV23) vaccination. Serotype-specific IgG against PPSV23-covered serotypes were measured by the World Health Organization (WHO) reference enzyme-linked immunosorbent assay (ELISA). Vaccine immunogenicity was compared using conversion rates (proportion of participants with IgG levels following immunization that are 2-fold greater than the baseline) and geometric mean fold rises (GMFRs) between the two groups, which were grouped according to pre-vaccination (baseline) IgG antibody levels.

RESULTS

Our data showed that over half of individuals have baseline IgG levels for 15 out of 23 serotypes above 1.3 µg/mL, and geometric mean concentrations (GMCs) were generally higher in the elderly group and the female group; significant differences were found in 15 serotypes for vaccine immunogenicity based on the seroconversion rate or GMFRs between individuals with baseline IgG ≥ 1.3 µg/mL and individuals with baseline IgG < 1.3 µg/mL. The seroconversion rate decreased with the increase of baseline IgG levels according to a linear regression model.

CONCLUSIONS

The assessment of vaccine immunogenicity could be impacted by the fact that many adults had high baseline antibody levels. This study is registered in the Chinese Clinical Trial Registry, number NCT05298800.

Pneumococcal Vaccination in Adults: A Narrative Review of Considerations for Individualized Decision-Making

Pneumococcal disease remains one of the major causes of severe disease in both children and adults. Severe disease may be prevented by pneumococcal polysaccharide and conjugate vaccines, which currently cover more than 20 serotypes. However, unlike routine pneumococcal vaccination in children, guidelines promote only limited pneumococcal vaccination in adults, and do not cater for decision-making for individual patients. In this narrative review, considerations for individualized decision-making are identified and discussed. This review identifies and discusses considerations for individualized decision-making, including the risk of severe disease, immunogenicity, clinical efficacy, mucosal immunity, herd immunity, concomitant administration with other vaccines, waning immunity, and replacement strains.

Memory T cell responses in seronegative older adults following SARS-CoV-2 vaccination

Generating memory T cell responses besides humoral immune responses is essential when it comes to the efficacy of a vaccine. In this study, the presence of memory T cell responses after aluminum-adjuvanted inactivated whole-virion SARS-CoV-2 vaccine (CoronaVac) in seronegative and seropositive elderly individuals were examined. CD4+ and CD8+ memory T cell proliferation and IFN-γ production capacities were evaluated. Additionally, clinical frailty scale (CFS) and FRAIL scales of the individuals were scored. CD4+ memory T cell responses more prominent than CD8+ memory T cells. In seronegative individuals, 80% of them had memory CD4+ and IFN-γ, whereas 50% of them had memory CD4+ and all of them had IFN-γ responses. Additionally, 40% of seronegative patients and 50% of seropositive patients had memory CD8+ responses. To sum up, humoral immune responses are not associated with memory T cell responses, and in seronegative individuals, memory T cell responses can be detected.

Declining Prevalence of SARS-CoV-2 Antibodies among Vaccinated Nursing Home Residents and Staff Six Months after the Primary BNT162b2 Vaccination Campaign in Belgium: A Prospective Cohort Study

In the SCOPE study, we monitored SARS-CoV-2 antibodies in a national sample of residents and staff from Belgian nursing homes. Here, we report the seroprevalence among infected and infection-naive residents and staff after the primary COVID-19 vaccination campaign. Among 1554 vaccinated nursing home residents and 1082 vaccinated staff from 69 nursing homes in Belgium, we assessed the proportion having SARS-CoV-2 antibodies approximately two (April 2021), four (June 2021), and six months (August 2021) after a two-dose regimen of the BNT162b2 vaccine. We measured the seroprevalence using SARS-CoV-2 antibody rapid tests and collected socio-demographic and COVID-19 medical data using an online questionnaire. Two months after vaccination (baseline), we found a seroprevalence of 91% (95% CI: 89-93) among vaccinated residents and 99% (95% CI: 98-99) among vaccinated staff. Six months after vaccination, the seroprevalence significantly decreased to 68% (95% CI: 64-72) among residents and to 89% (95% CI; 86-91) among staff (p < 0.001). The seroprevalence was more likely to decrease among infection-naive residents, older residents, or residents with a high care dependency level. These findings emphasize the need for close monitoring of nursing home residents, as a substantial part of this population fails to mount a persistent antibody response after BNT162b2 vaccination.

Humoral immunity induced by mRNA COVID-19 vaccines in Nursing Home Residents previously infected with SARS-CoV-2

BACKGROUND

Nursing home (NH) residents suffered the greatest impact of the COVID-19 pandemic. Limited data are available on vaccine-induced immunity and on the protection ensured by a prior infection in this population.

AIMS

The present study aims to monitor antibody levels and their persistence over a 6-month period in NH residents according to the history of prior SARS-CoV-2 infection.

METHODS

We measured anti-trimeric Spike IgG antibody levels in a sample of 395 residents from 25 NHs in 6 Italian Regions at study enrolment (prior to the first dose of vaccine, T0) and then after 2 (T1) and 6 months (T2) following the first vaccine dose. All participants received mRNA vaccines (BNT162b2 or mRNA-1273). Analyses were performed using log-transformed values of antibody concentrations and geometric means (GM) were calculated.

RESULTS

Superior humoral immunity was induced in NH residents with previous SARS-CoV-2 infection. (T0: GM 186.6 vs. 6.1 BAU/ml, p < 0.001; T1: GM 5264.1 vs. 944.4 BAU/ml, p < 0.001; T2: GM 1473.6 vs. 128.7 BAU/ml, p < 0.001). Residents with prior SARS-CoV-2 infection receiving two vaccine doses presented significantly higher antibody concentration at T1 and T2. A longer interval between previous infection and vaccination was associated with a better antibody response over time.

DISCUSSION

In a frail sample of NH residents, prior SARS-CoV-2 infection was associated with a higher humoral response to vaccination. Number of vaccine doses and the interval between infection and vaccination are relevant parameters in determining humoral immunity.

CONCLUSIONS

These findings provide important information to plan future immunization policies and disease prevention strategies in a highly vulnerable population.

Antibody response with SARS-CoV-2 inactivated vaccine (CoronaVac) in Turkish geriatric population

Background

Sars-CoV-2 infection influences older individuals at the forefront, and there is still limited data on the COVID-19 vaccine response in the geriatric population. This study aimed to assess antibody response after vaccination with SARS-CoV-2 inactivated vaccine and examine possible factors affecting this response in a geriatric population.

Methods

individuals who have been on at least the 28th day after the second dose of the COVID-19 vaccine were included. Comprehensive geriatric assessment tools and the Clinical Frailty Scale were performed. SARS-CoV-2 spike-specific IgG antibodies were detected and, levels ≥1 U/ml were defined as seropositive, <1 U/ml were defined as seronegative.

Results

a total of 497 patients were included and divided into three groups according to the days past after the second dose of the vaccine (Group 1: 28–59 days, Group 2: 60–89 days and Group 3: 90 days and more). Groups included 188, 148 and 171 patients, respectively. Seropositivity rate in each group was 80.9,73.2 and 57.3%, respectively. In Groups 1 and 2, Charlson Comorbidity Index score was higher in the seronegative group (P = 0.023 and P = 0.011, respectively). In Group 3, the prevalence of frailty was significantly higher in the seronegative group (P = 0.002).

Conclusion

to the best of our knowledge, this is the first study assessing the antibody response after vaccination with Sars-CoV 2 inactivated vaccine in the Turkish geriatric population. Moreover, this is the first study revealing the relationship between antibody response and frailty. Larger studies are needed to confirm the antibody response duration and the association between frailty and COVID-19 vaccine response.

Changes in dietary total and non-haem iron intake is associated with incident frailty in older men: The Concord Health and Ageing in Men Project

Background

Nutritional intake could influence the development of frailty. The aim was to evaluate the associations between dietary iron intakes and changes in dietary iron intakes with frailty.

Methods

Cross-sectional analyses involved 785 men with Fried frailty phenotype (FP) and 758 men with Rockwood frailty index (FI) data aged 75 years and older at nutrition assessment from the Concord Health and Ageing in Men Project prospective cohort study. Of these, 563 men who were FP robust or prefrail, and 432 men who were FI nonfrail were included in the longitudinal analyses for more than 3 years. Dietary intake was assessed at both timepoints using a validated diet history questionnaire. The dietary calculation was used to derive heme iron and nonheme iron intakes from total iron intakes. The associations were evaluated through binary logistic regression.

Results

Incidence of FP frailty was 15.3% (n = 86). In longitudinal analyses, maintaining total iron intakes (medium tertile −2.61–0.81 mg/d), increases in total iron and nonheme iron intakes (high tertiles ≥0.82 mg/d and ≥0.80 mg/d), and changes in nonheme iron intake (1 mg increment) were associated with reduced risks of incident FP frailty (OR: 0.47 [95% confindence interval (CI): 0.24, 0.93, p = .031], OR 0.48 [95% CI: 0.23, 0.99, p = .048], OR 0.41 [95% CI: 0.20, 0.88, p = .022], and OR 0.89 [95% CI: 0.82, 0.98, p = .017]).

Conclusion

Maintaining or increases in total dietary iron and increases or changes in dietary nonheme iron intakes more than 3 years were associated with reduced incidence of FP frailty in older men.

Can vaccination roll-out be more equitable if population risk is taken into account?

Background

COVID-19 vaccination in many countries, including England, has been prioritised primarily by age. However, people of the same age can have very different health statuses. Frailty is a commonly used metric of health and has been found to be more strongly associated with mortality than age among COVID-19 inpatients.

Methods

We compared the number of first vaccine doses administered across the 135 NHS Clinical Commissioning Groups (CCGs) of England to both the over 50 population and the estimated frail population in each area. Area-based frailty estimates were generated using the English Longitudinal Survey of Ageing (ELSA), a national survey of older people. We also compared the number of doses to the number of people with other risk factors associated with COVID-19: atrial fibrillation, chronic kidney disease, diabetes, learning disabilities, obesity and smoking status.

Results

We estimate that after 79 days of the vaccine program, across all Clinical Commissioning Group areas, the number of people who received a first vaccine per frail person ranged from 4.4 (95% CI 4.0-4.8) and 20.1 (95% CI 18.3-21.9). The prevalences of other risk factors were also poorly associated with the prevalence of vaccination across England.

Conclusions

Vaccination with age-based priority created area-based inequities in the number of doses administered relative to the number of people who are frail or have other risk factors associated with COVID-19. As frailty has previously been found to be more strongly associated with mortality than age for COVID-19 inpatients, an age-based priority system may increase the risk of mortality in some areas during the vaccine roll-out period. Authorities planning COVID-19 vaccination programmes should consider the disadvantages of an age-based priority system.

Vaccination of older adults: Influenza, pneumococcal disease, herpes zoster, COVID-19 and beyond

Preserving good health in old age is of utmost importance to alleviate societal, economic and health care-related challenges caused by an aging society. The prevalence and severity of many infectious diseases is higher in older adults, and in addition to the acute disease, long-term sequelae, such as exacerbation of underlying chronic disease, onset of frailty or increased long-term care dependency, are frequent. Prevention of infections e.g. by vaccination is therefore an important measure to ensure healthy aging and preserve quality of life. Several vaccines are specifically recommended for older adults in many countries, and in the current SARS-CoV-2 pandemic older adults were among the first target groups for vaccination due to their high risk for severe disease. This review highlights clinical data on the influenza, Streptococcus pneumoniae and herpes zoster vaccines, summarizes recent developments to improve vaccine efficacy, such as the use of adjuvants or higher antigen dose for influenza, and gives an overview of SARS-CoV-2 vaccine development for older adults. Substantial research is ongoing to further improve vaccines, e.g. by developing universal influenza and pneumococcal vaccines to overcome the limitations of the current strain-specific vaccines, and to develop novel vaccines against pathogens, which cause considerable morbidity and mortality in older adults, but for which no vaccines are currently available. In addition, we need to improve uptake of the existing vaccines and increase awareness for life-long vaccination in order to provide optimal protection for the vulnerable older age group.

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.

The Impact of Frailty on the Effectiveness and Safety of Intensive Glucose Control and Blood Pressure-Lowering Therapy for People With Type 2 Diabetes: Results From the ADVANCE Trial

OBJECTIVE

To develop a frailty index (FI) and explore the relationship of frailty to subsequent adverse outcomes on the effectiveness and safety of more intensive control of both blood glucose and blood pressure (BP), among participants with type 2 diabetes in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial.

RESEARCH DESIGN AND METHODS

Cox proportional hazard models were used to estimate the effectiveness and safety of intensive glucose control and BP intervention according to frailty (defined as FI >0.21) status. The primary outcomes were macro- and microvascular events. The secondary outcomes were all-cause mortality, cardiovascular mortality, severe hypoglycemia, and discontinuation of BP treatment due to hypotension/dizziness.

RESULTS

There were 11,140 participants (mean age, 65.8 years; 42.5% women, 25.7% frail). Frailty was an independent predictor of all primary outcomes and secondary outcomes. The effect of intensive glucose treatment on primary outcomes showed some evidence of attenuation in the frail: hazard ratios for combined major macro- and microvascular events 1.03 (95% CI 0.90-1.19) in the frail versus 0.84 (95% CI 0.74-0.94) in the nonfrail (P = 0.02). A similar trend was observed with BP intervention. Severe hypoglycemia rates (per 1,000 person-years) were higher in the frail: 8.39 (6.15-10.63) vs. 4.80 (3.84-5.76) in nonfrail (P < 0.001). There was no significant difference in discontinuation of BP treatment between frailty groups.

CONCLUSIONS

It was possible to retrospectively estimate frailty in a trial population, and this FI identified those at higher risk of poor outcomes. Participants with frailty had some attenuation of benefit from intensive glucose-lowering and BP-lowering treatments.

Intranasal Vaccine Delivery Technology for Respiratory Tract Disease Application with a Special Emphasis on Pneumococcal Disease

This mini-review will cover recent trends in intranasal (IN) vaccine delivery as it relates to applications for respiratory tract diseases. The logic and rationale for IN vaccine delivery will be compared to methods and applications accompanying this particular administration route. In addition, we will focus extended discussion on the potential role of IN vaccination in the context of respiratory tract diseases, with a special emphasis on pneumococcal disease. Here, elements of this disease, including its prevalence and impact upon the elderly population, will be viewed from the standpoint of improving health outcomes through vaccine design and delivery technology and how IN administration can play a role in such efforts.

Older but Not Wiser: the Age-Driven Changes in Neutrophil Responses during Pulmonary Infections

Elderly individuals are at increased risk of life-threatening pulmonary infections. Neutrophils are a key determinant of the disease course of pathogen-induced pneumonia. Optimal host defense balances initial robust pulmonary neutrophil responses to control pathogen numbers, ultimately followed by the resolution of inflammation to prevent pulmonary damage. Recent evidence suggests that phenotypic and functional heterogeneity in neutrophils impacts host resistance to pulmonary pathogens. Apart from their apparent role in innate immunity, neutrophils also orchestrate subsequent adaptive immune responses during infection. Thus, the outcome of pulmonary infections can be shaped by neutrophils. This review summarizes the age-driven impairment of neutrophil responses and the contribution of these cells to the susceptibility of the elderly to pneumonia. We describe how aging is accompanied by changes in neutrophil recruitment, resolution, and function. We discuss how systemic and local changes alter the neutrophil phenotype in aged hosts. We highlight the gap in knowledge of whether these changes in neutrophils also contribute to the decline in adaptive immunity seen with age. We further detail the factors that drive dysregulated neutrophil responses in the elderly and the pathways that may be targeted to rebalance neutrophil activity and boost host resistance to pulmonary infections.

Evaluation of the geroprotective effects of withaferin A in Drosophila melanogaster

Withanolides are a class of compounds usually found in plant extracts which are an attractive geroprotective drug design starting point. We evaluated the geroprotective properties of Withaferin A (WA) in vivo using the Drosophila model. Flies were supplemented by nutrient medium with WA (at a concentration of 1, 10, or 100 μM dissolved in ethanol) for the experiment group and 30 μM of ethanol for the control group. WA treatment at 10 and 100 μM concentrations prolong the median life span of D. melanogaster's male by 7.7, 9.6% (respectively) and the maximum life span (the age of death 90% of individuals) by 11.1% both. Also WA treatment at 1, 10 and 100 μM improved the intestinal barrier permeability in older flies and affected an expression of genes involved in antioxidant defense (PrxV), recognition of DNA damage (Gadd45), heat shock proteins (Hsp68, Hsp83), and repair of double-strand breaks (Ku80). WA was also shown to have a multidirectional effect on the resistance of flies to the prooxidant paraquat (oxidative stress) and 33° C hyperthermia (heat shock). WA treatment increased the resistance to oxidative stress in males at 4 and 7 week old and decreased it at 6 weeks old. It increased the male's resistance to hyperthermia at 2, 4 and 7 weeks old and decreased it at 3, 5 and 8 weeks old. WA treatment decreased the resistance to hyperthermia in females at 1, 2 and 3 weeks old and not affected on their resistance to oxidative stress.

Liposomal Encapsulation of Polysaccharides (LEPS) as an Effective Vaccine Strategy to Protect Aged Hosts Against S. pneumoniae Infection

Despite the availability of licensed vaccines, pneumococcal disease caused by the bacteria Streptococcus pneumoniae (pneumococcus), remains a serious infectious disease threat globally. Disease manifestations include pneumonia, bacteremia, and meningitis, resulting in over a million deaths annually. Pneumococcal disease disproportionally impacts older adults aged ≥65 years. Interventions are complicated through a combination of complex disease progression and 100 different bacterial capsular polysaccharide serotypes. This has made it challenging to develop a broad vaccine against S. pneumoniae, with current options utilizing capsular polysaccharides as the primary antigenic content. However, current vaccines are substantially less effective in protecting the elderly. We previously developed a Liposomal Encapsulation of Polysaccharides (LEPS) vaccine platform, designed around limitations of current pneumococcal vaccines, that allowed the noncovalent coupling of polysaccharide and protein antigen content and protected young hosts against pneumococcal infection in murine models. In this study, we modified the formulation to make it more economical and tested the novel LEPS vaccine in aged hosts. We found that in young mice (2-3 months), LEPS elicited comparable responses to the pneumococcal conjugate vaccine Prevnar-13. Further, LEPS immunization of old mice (18-22 months) induced comparable antibody levels and improved antibody function compared to Prevnar-13. Importantly, LEPS protected old mice against both invasive and lung localized pneumococcal infections. In summary, LEPS is an alternative and effective vaccine strategy that protects aged hosts against different manifestations of pneumococcal disease.

Recombinant Zoster Vaccine Is Efficacious and Safe in Frail Individuals

BACKGROUND/OBJECTIVES

Frail participants are often under-represented in randomized trials, raising questions about outcomes of interventions in real-world settings. Frailty is strongly associated with vulnerability to illness and adverse health outcomes. We studied the impact of frailty on recombinant zoster vaccine (RZV) clinical outcomes.

DESIGN/SETTING

Data from two previously conducted phase III randomized trials of RZV were pooled. These two parent trials were conducted concurrently at the same study sites using the same methods.

PARTICIPANTS/INTERVENTION

In the two parent studies, participants aged ≥50 years (ZOE-50 study) and ≥70 years (ZOE-70 study), respectively, were randomized 1:1 to receive two doses of RZV or placebo.

MEASUREMENTS

In the current ZOE-Frailty study (NCT03563183), a frailty index was created using previously validated methods. Clinical outcomes assessed by frailty status included vaccine efficacy, immunogenicity, reactogenicity, and safety.

RESULTS

Of 29,305 participants from the pooled ZOE-50 and ZOE-70 total vaccinated cohort, 92% were included in this study. Mean age was 68.8 years; 58.1% were women; 45.6% were pre-frail and 11.3% frail. The percentage of frail participants increased with age from 5.7% aged 50-59 years to 22.7% aged ≥80 years. RZV vaccine efficacy against herpes zoster was >90% for all frailty subgroups (non-frail: 95.8% (95% confidence interval = 91.6-98.2), pre-frail: 90.4% (84.4-94.4), frail: 90.2% (75.4-97.0)). The RZV group demonstrated robust anti-gE antibody and gE-specific CD4²⁺ responses, with mean concentrations remaining above pre-vaccination levels at least 3 years post-dose two, in all frailty subgroups. In the RZV group, the percentage of participants reporting solicited adverse events tended to decrease with increasing frailty.

CONCLUSION

The relatively nonrestrictive inclusion/exclusion criteria in the parent ZOE studies resulted in a range of participants that included frail and pre-frail older adults. RZV significantly reduced the risk of herpes zoster across all frailty subgroups.

Comparison of alternative full and brief versions of functional status scales among older adults in China

BACKGROUND

Brief assessments of functional status for community-dwelling older adults are needed given expanded interest in the measurement of functional decline.

METHODS

As part of a 2015 prospective cohort study of older adults aged 60-89 years in Jiangsu Province, China, 1506 participants were randomly assigned to two groups; each group was administered one of two alternative 20-item versions of a scale to assess activities of daily living (ADL) and instrumental activities of daily living (IADL) drawn from multiple commonly-used scales. One version asked if they required help to perform activities (ADL-IADL-HELP-20), while the other version provided additional response options if activities could be done alone but with difficulty (ADL-IADL-DIFFICULTY-20). Item responses to both versions were compared using the binomial test for differences in proportion (with Wald 95% confidence interval [CI]). A brief 9-item scale (ADL-IADL-DIFFICULTY-9) was developed favoring items identified as difficult or requiring help by ≥4%, with low redundancy and/or residual correlations, and with significant correlations with age and other health indicators. We repeated assessment of the measurement properties of the brief scale in two subsequent samples of older adults in Hong Kong in 2016 (aged 70-79 years; n = 404) and 2017 (aged 65-82 years; n = 1854).

RESULTS

Asking if an activity can be done alone but with difficulty increased the proportion of participants reporting restriction on 9 of 20 items, for which 95% CI for difference scores did not overlap with zero; the proportion with at least one limitation increased from 28.6% to 34.2% or an absolute increase of 5.6% (95% CI = 0.9-10.3%), which was a relative increase of 19.6%. The brief ADL-IADL-DIFFICULTY-9 maintained excellent internal consistency (α = 0.93) and had similar ceiling effect (68.1%), invariant item ordering (H trans = .41; medium), and correlations with age and other health measures compared with the 20-item version. The brief scale performed similarly when subsequently administered to older adults in Hong Kong.

CONCLUSIONS

Asking if tasks can be done alone but with difficulty can modestly reduce ceiling effects. It's possible that the length of commonly-used scales can be reduced by over half if researchers are primarily interested in a summed indicator rather than an inventory of specific types of deficits.

Vaccines to Prevent Infectious Diseases in the Older Population: Immunological Challenges and Future Perspectives

Infectious diseases are a major cause for morbidity and mortality in the older population. Demographic changes will lead to increasing numbers of older persons over the next decades. Prevention of infections becomes increasingly important to ensure healthy aging for the individual, and to alleviate the socio-economic burden for societies. Undoubtedly, vaccines are the most efficient health care measure to prevent infections. Age-associated changes of the immune system are responsible for decreased immunogenicity and clinical efficacy of most currently used vaccines in older age. Efficacy of standard influenza vaccines is only 30-50% in the older population. Several approaches, such as higher antigen dose, use of MF59 as adjuvant and intradermal administration have been implemented in order to specifically target the aged immune system. The use of a 23-valent polysaccharide vaccine against Streptococcus pneumoniae has been amended by a 13-valent conjugated pneumococcal vaccine originally developed for young children several years ago to overcome at least some of the limitations of the T cell-independent polysaccharide antigens, but still is only approximately 50% protective against pneumonia. A live-attenuated vaccine against herpes zoster, which has been available for several years, demonstrated efficacy of 51% against herpes zoster and 67% against post-herpetic neuralgia. Protection was lower in the very old and decreased several years after vaccination. Recently, a recombinant vaccine containing the viral glycoprotein gE and the novel adjuvant AS01B has been licensed. Phase III studies demonstrated efficacy against herpes zoster of approx. 90% even in the oldest age groups after administration of two doses and many countries now recommend the preferential use of this vaccine. There are still many infectious diseases causing substantial morbidity in the older population, for which no vaccines are available so far. Extensive research is ongoing to develop vaccines against novel targets with several vaccine candidates already being clinically tested, which have the potential to substantially reduce health care costs and to save many lives. In addition to the development of novel and improved vaccines, which specifically target the aged immune system, it is also important to improve uptake of the existing vaccines in order to protect the vulnerable, older population.

Cross-Sectional and Longitudinal Relationships Between Inflammatory Biomarkers and Frailty in Community-dwelling Older Men: The Concord Health and Ageing in Men Project

BACKGROUND

Previous studies demonstrated associations between IL-6 and frailty, but associations between a wide range of cytokines, chemokines, and growth factors with prevalent and incident frailty has not been studied.

METHODS

Community-dwelling men aged more than 75 enrolled in the 5-year and 8-year follow-up of the CHAMP study were assessed. Twenty-seven inflammatory biomarkers were measured using the Bio-Plex Pro Human Cytokine 27-plex Assay kit at 5-year follow-up. Frailty was determined using the Fried frailty phenotype (FP) and Rockwood frailty index (FI) at both time-points. Age, body mass index, smoking, alcohol, and comorbidity were also assessed.

RESULTS

In cross-sectional analysis of the 5-year follow-up, the unadjusted odds ratio (OR) for frail versus robust evaluated by the FP showed significant associations for IL-6 (OR: 1.56, 95% confidence interval [CI]: 1.23-1.98) and IL-8 (OR: 1.28, 95% CI: 1.00-1.63). IL-6 remained significantly associated in the age-adjusted (OR: 1.58, 95% CI: 1.21-2.05) and multivariable-adjusted model (OR: 1.54, 95% CI: 1.16-2.05). No associations were observed between pre-frail versus robust. In longitudinal unadjusted analysis, IL-8 (OR: 1.32, 95% CI: 1.03-1.70) and IP-10 (OR: 1.32, 95% CI: 1.03-1.70) at 5-year predicted incident frailty at 8-year follow-up. IL-8 remained longitudinally associated with incident frailty after age (OR: 1.34, 95% CI: 1.03-1.75) but not multivariable (OR: 1.20, 95% CI: 0.98-1.70) adjustment. Similar results were seen using the FI. None of the other biomarkers had significant associations with incident frailty.

CONCLUSIONS

Our findings suggest that IL-6 and IL-8 may be cross-sectionally associated with frailty and that all measured inflammatory biomarkers were not causally related to frailty. Together with previous studies, the results suggest that frailty is specifically linked to IL-6 and IL-8 rather than simply representing a nonspecific pan-inflammatory condition.

Frailty and Cause-Specific Hospitalizations in Community-Dwelling Older Men

OBJECTIVES

The types of medical conditions leading to hospitalization in frail older people have not been investigated. The objectives were to evaluate associations between frailty and (a) risk of all-cause and cause-specific hospitalization, and (b) rate of all-cause and cause-specific hospitalizations.

DESIGN, SETTING AND PARTICIPANTS

Community-dwelling men aged 70+ years in the Concord Health and Ageing in Men Project (CHAMP) were assessed for frailty at baseline (2005-2007, n=1705).

MEASUREMENTS

Frailty was determined by both the Fried frailty phenotype (FP) and the Rockwood frailty index (FI). Non-elective and elective hospitalization data were accessed from the New South Wales (NSW) Admitted Patient Data Collection and mortality from the NSW Deaths Registry for the period 2005-2017. Causes of hospitalization were categorized using ICD-10 classification of principal diagnoses based on organ system involved into 14 major categories.

RESULTS

Nearly 80% of CHAMP men had at least one non-elective hospitalization and 63% had an elective hospitalization over a 9-year follow-up. Men with FP frailty were twice as likely to have a non-elective hospitalization (HR: 1.98, 95%CI: 1.61-2.44) and a greater number of non-elective hospitalizations (IRR: 1.44, 95%CI: 1.22-1.70). Similar relationships were found between FI frailty and non-elective hospitalizations. Men with frailty (either FP or FI) were more likely to have at least one non-elective hospitalization for 13 of the 14 cause-related admissions. In contrast, frailty was only associated with 3 cause-related elective hospitalizations. Men with frailty were also more likely to have an increased number of non-elective hospitalizations for all 14 causes, but only for 6 causes of elective hospitalizations.

CONCLUSIONS

Our findings suggest frailty increases the risk and number of non-elective hospitalizations in older men for a wide range of cause. Strategies on early identification of frailty, followed by appropriate preventative strategies to lower the risk of non-elective hospital admissions are warranted.

Frailty in Older Patients with Acute Coronary Syndrome in Vietnam

Background

There has been limited evidence about frailty in older patients with acute coronary syndrome (ACS) in Vietnam.

Aim

(1) To investigate the prevalence of frailty in older patients hospitalised with ACS and its associated factors; (2) To investigate the impact of frailty on percutaneous coronary intervention (PCI) and adverse outcomes in this population.

Methods

Patients aged ≥60 with ACS admitted to two teaching hospitals in Vietnam were recruited from 9/2017 to 4/2018. Frailty was defined by the Reported Edmonton Frail Scale. Multivariate logistic regression was applied to investigate the associated factors of frailty and the impact of frailty on PCI and adverse outcomes.

Results

There were 324 participants, mean age 73.5±8.3, 39.2% female. The prevalence of frailty was 48.1%. Advanced age, female gender, history of hypertension, heart failure, stroke and chronic kidney disease were significantly associated with a frailty status. Overall, 50.3% of the participants received PCI (58.3% in the non-frail vs 41.7% in the frail, p=0.003). However, frailty did not have an independent impact on PCI (adjusted OR 0.66, 95% CI 0.41–1.08). Frailty was significantly associated with increased risk of having arrhythmia during hospitalisation (adjusted OR 2.24, 95% CI 1.32–3.80), hospital-acquired pneumonia (adjusted OR 2.27, 95% CI 1.24–4.17), in-hospital mortality (adjusted OR 3.02, 95% CI 1.35–6.75), 30-day mortality (adjusted OR 3.28, 95% CI 1.59–6.76), and 30-day readmission (adjusted OR 2.53, 95% CI 1.38–4.63).

Conclusion

In this study, frailty was present in nearly half of older patients with ACS and was associated with increased adverse outcomes. These findings suggest that frailty screening should be performed in older patients with ACS in Vietnam.

Neutrophils in community-acquired pneumonia: parallels in dysfunction at the extremes of age

"Science means constantly walking a tight rope" Heinrich Rohrer, physicist, 1933. Community-acquired pneumonia (CAP) is the leading cause of death from infectious disease worldwide and disproportionately affects older adults and children. In high-income countries, pneumonia is one of the most common reasons for hospitalisation and (when recurrent) is associated with a risk of developing chronic pulmonary conditions in adulthood. Pneumococcal pneumonia is particularly prevalent in older adults, and here, pneumonia is still associated with significant mortality despite the widespread use of pneumococcal vaccination in middleand high-income countries and a low prevalence of resistant organisms. In older adults, 11% of pneumonia survivors are readmitted within months of discharge, often with a further pneumonia episode and with worse outcomes. In children, recurrent pneumonia occurs in approximately 10% of survivors and therefore is a significant cause of healthcare use. Current antibiotic trials focus on short-term outcomes and increasingly shorter courses of antibiotic therapy. However, the high requirement for further treatment for recurrent pneumonia questions the effectiveness of current strategies, and there is increasing global concern about our reliance on antibiotics to treat infections. Novel therapeutic targets and approaches are needed to improve outcomes. Neutrophils are the most abundant immune cell and among the first responders to infection. Appropriate neutrophil responses are crucial to host defence, as evidenced by the poor outcomes seen in neutropenia. Neutrophils from older adults appear to be dysfunctional, displaying a reduced ability to target infected or inflamed tissue, poor phagocytic responses and a reduced capacity to release neutrophil extracellular traps (NETs); this occurs in health, but responses are further diminished during infection and particularly during sepsis, where a reduced response to granulocyte colony-stimulating factor (G-CSF) inhibits the release of immature neutrophils from the bone marrow. Of note, neutrophil responses are similar in preterm infants. Here, the storage pool is decreased, neutrophils are less able to degranulate, have a reduced migratory capacity and are less able to release NETs. Less is known about neutrophil function from older children, but theoretically, impaired functions might increase susceptibility to infections. Targeting these blunted responses may offer a new paradigm for treating CAP, but modifying neutrophil behaviour is challenging; reducing their numbers or inhibiting their function is associated with poor clinical outcomes from infection. Uncontrolled activation and degranulation can cause significant host tissue damage. Any neutrophil-based intervention must walk the tightrope described by Heinrich Rohrer, facilitating necessary phagocytic functions while preventing bystander host damage, and this is a significant challenge which this review will explore.

Altered immune system in frailty: Genetics and diet may influence inflammation

Frailty is a complex geriatric syndrome associated with biological vulnerability to stressors and decreased physiological reserve. Its etiology and pathogenesis are not completely understood, although various causes and complex pathways have been proposed. Immune system alterations (immunosenescence and "InflammAging") have been suggested to contribute to frailty, but a precise causative role of such alterations remains to be determined. Genetic studies support the suggestion of immune system involvement in frailty: genetic variants in genes involved in immune system function have been associated with the syndrome. Interestingly, nutritional status, through its effects on cellular metabolism, may also influence the immune system, i.e. hormone and cytokine (mainly adipocytokine) levels, and immune cell populations and function, increasing inflammation and contributing to frailty. This review aims to discuss the role of immune system alterations in frailty, analyzing the role of genetic factors in frailty onset and the impact of diet on inflammation and, in turn, on frailty.

Hematopoietic Cell Transplant-Related Toxicities and Mortality in Frail Recipients

Frailty is a state characterized by diminished physiologic reserve and increased vulnerability to stress and adversely affects outcomes in older patients. We aimed to determine the relationship between pre-hematopoietic cell transplant (HCT) frailty and grades 3 to 4 nonhematologic toxicities (Common Terminology Criteria for Adverse Events, version 5.0) and mortality in HCT recipients within 1 year after HCT and also examined whether age at HCT moderated that association. In a prospective longitudinal study of 117 patients aged ≥ 40 years undergoing HCT, we performed formal pre-HCT geriatric assessments. Frailty was assessed using Fried's criteria. Post-HCT toxicities were abstracted through medical record reviews. The prevalence of pre-HCT frailty was 21% and was not different in younger (40 to 59 years) versus older (≥60 years) HCT recipients. Overall, frail recipients (versus nonfrail) had a higher cumulative incidence of any grades 3 to 4 nonhematologic toxicity (86% [95% confidence interval {CI}, 62% to 100%] versus 70% [95% CI, 57% to 83%), P = .03) and more organ-specific grades 3 to 4 toxicities, such as non-neutropenic infections (38% [95% CI, 17% to 59%] versus 13% [95% CI, 6% to 20%], P < .01), nervous system disorders (19% [95% CI, 3% to 35%] versus 4% [95% CI, 0 to 8%], P = .02), and pneumonia (38% [95% CI, 17% to 59%] versus 10% [95% CI, 4% to 17%], P < .01). Frail recipients were 1.9-fold (95% CI, 1.1 to 3.4) more likely to develop any grades 3 to 4 toxicities (P = .03), 4-fold more likely to suffer non-neutropenic infections (95% CI, 1.4 to 11) and pneumonia (95% CI, 1.4 to 12; both P = .01), and 8.6-fold (95% CI, 1.6 to 45.3) more likely to suffer nervous system disorders (P = .01). Frail allogeneic HCT recipients also had a 3.1 times (95% CI, .9 to 9.7; P = .06) higher risk of overall mortality as compared with nonfrail allogeneic HCT recipients. The higher toxicity and mortality observed in frail allogeneic recipients needs to be monitored with high attention. Studies focusing on interventions to reduce frailty and manage morbidities are needed.

Antibody and B cell responses to an investigational adjuvanted RSV vaccine for older adults

Background: Infections with respiratory syncytial virus (RSV) cause significant morbidity and hospitalization in older adults. We studied the humoral, mucosal and B cell responses of an investigational adjuvanted RSV sF vaccine, MEDI7510, in older adults. Methods: In a substudy of a randomized (1:1), double-blind, placebo-controlled study of MEDI7510 in adults ≥60 years of age, we collected blood and nasal secretions at days 0, 8, 29, 91 and 180 post-vaccination to measure F-specific IgG and IgA antibodies by ELISA, and plasmablasts and memory B cells by IgA/IgG dual-color fluorospot. Results: The 27 vaccine- and 18 placebo-recipients had a mean age of 73 years and included 24 women. Among vaccinees, 93% had significant increases in F-specific plasma IgG 85% had increased plasma IgA; 74% had increased nasal IgG and 26% nasal IgA; 93% had IgG and 89% IgA plasmablasts on Day 8 post-immunization; and 82% had IgG and 7.4% IgA memory B cell responses to the vaccine. Vaccinees <70 years of age and women had the highest responses to the vaccine. Conclusions: This adjuvanted vaccine generated robust humoral immune responses in older adults, including RSV F-specific systemic and mucosal antibodies and memory B cells. Nevertheless, age ≥70 years was associated with decreased immunogenicity of the adjuvanted vaccine.

A survey of vaccine history in German cats and owners' attitudes to vaccination

OBJECTIVES

Vaccination is the most important measure for prevention of feline infectious diseases. Cat owner compliance with vaccination recommendations has been investigated in the UK but not in other European countries. The aim of the present study was to determine cat owners' attitudes towards vaccination in cats in Germany, to identify factors that are associated with the vaccination status of their cats and to compare the results with those of the UK survey.

METHODS

The survey was conducted using an online questionnaire and was aimed at respondents throughout Germany. Respondents under 16 years of age, cats that were less than 9 weeks old and veterinarians were excluded. A total of 920 questionnaires were evaluated, and information about cats and respondents was assessed with respect to the current vaccination status of the cats using a linear logistic regression model.

RESULTS

The majority of cats (77.9%; n = 717) were vaccinated according to current guidelines; only 5.4% (n = 50; 95% confidence interval [CI] 5.00-9.00) of cats had never received a vaccine. Having visited a cattery, a cat show or travelled abroad in the past 12 months (n = 96/773; odds ratio [OR] 6.95; 95% CI 1.65-52.19) had the highest positive impact on the vaccination status of cats. In addition, detailed veterinary advice about vaccination had a positive impact (n = 275/773; OR 2.09; 95% CI 0.67-6.25) on the attitude of owners towards vaccinating their cats.

CONCLUSIONS AND RELEVANCE

A history of travelling abroad or visiting cat shows or a cattery, and thus regulatory requirements, had the greatest positive impact on the current vaccination status of the cats. Veterinary consultation on preventive measures, including vaccination, is crucial for protecting the cat population against infectious diseases.

Healthy elderly Singaporeans show no age-related humoral hyporesponsiveness nor diminished plasmablast generation in response to influenza vaccine

Abstract

Improving influenza vaccine efficacy is a priority to reduce the burden of influenza-associated morbidity and mortality. By careful selection of individuals based on health we show sustained response to influenza vaccination in older adults. Sustaining health in aging could be an important player in maintaining immune responses to influenza vaccination.

Trial registration

NCT03266237. Registered 30 August 2017, https://clinicaltrials.gov/ct2/show/NCT03266237.

Influenza Vaccine-Induced Antibody Responses Are Not Impaired by Frailty in the Community-Dwelling Elderly With Natural Influenza Exposure

Background: Elderly adults over 65 years of age are recommended to receive seasonal influenza vaccination as they are at a higher risk of infection and its complications than the younger community. The elderly are often stratified according to frailty status where frail individuals are more susceptible to adverse health outcomes than their non-frail counterparts, however, it is not known whether immunity induced by influenza vaccination is impaired in the frail elderly.

Study Design: Two hundred and five elderly subjects of Chinese ethnicity in Singapore (mean age 73.3 ± 5.3 years, 128 females and 77 males) were administered the recommended trivalent inactivated 2013–14 seasonal influenza vaccine (Vaxigrip™) containing A/H1N1, A/H3N2, and B strains. The elderly subjects were stratified into three groups according to Fried's frailty criteria (59 frail, 85 pre-frail, 61 robust) and were also ranked by Rockwood's frailty index (RFI). Statistical associations were evaluated between frailty status and pre- and post-vaccination antibody titres in sera measured by Hemagglutination inhibition (HAI) and microneutralization (MN) assays. Immunological responses across frailty strata were also studied in terms of leukocyte cellular distribution, cytokine levels and gene expression.

Results: Post-vaccination, 83.4% of the subjects seroconverted for A/H1N1, 80.5% for A/H3N2, and 81% for the B strain. The seroconversion rates were comparable across frailty groups (A/H1N1, ANOVA, p = 0.7910; A/H3N2, ANOVA, p = 0.8356, B, ANOVA, p = 0.9741). Geometric mean titres of HAI and MN as well as seroprotection rates were also similar in all three frailty groups and uncorrelated with RFI (Spearman, r = 0.023, p = 0.738). No statistically significant differences were observed between the frailty groups in vaccine-induced modulation of leukocyte populations, cytokine responses, and gene expression profiles of peripheral blood mononuclear cells (PBMCs). Whereas, post- and pre-vaccination HAI titres were positively correlated after adjusting for age and gender (A/H1N1, R² = 0.216, p = 9.1e−11; A/H3N2, R² = 0.166, p = 3.4e−8; B, R² = 0.104, p = 3.1e−5). With most subjects lacking previous history of influenza vaccination, the pre-vaccination titres were likely due to natural exposure and seen to match the pattern of influenza subtype prevalence in the time period of vaccination.

Conclusion: The majority of the elderly subjects seroconverted for seasonal influenza upon vaccination, and importantly, influenza vaccination-induced humoral immune responses and seroprotection were similar across the frailty strata, indicating that frail individuals may also benefit from influenza vaccination. Pre-existing antibodies due to natural exposure appeared to positively influence vaccine-induced antibody responses.

Influence of Aging and Environment on Presentation of Infection in Older Adults

In older adults, pathophysiologic, clinical, and environmental factors all affect the presentation of infections. We explore how age-related changes influence the manifestation and evaluation of infections in this population. Specific topics include immunosenescence, age-related organ-specific physiologic changes, and frailty. We also describe clinical factors influencing infection risk and presentation in older adults, including temperature regulation, cognitive decline, and malnutrition. Finally, we discuss the influence of the setting in which older adults reside on the clinical evaluation of infection. Understanding the influence of all these changes may facilitate the prevention, early recognition, and treatment of infections in older adults.

Nasopharyngeal Exposure to Streptococcus pneumoniae Induces Extended Age-Dependent Protection against Pulmonary Infection Mediated by Antibodies and CD138+ Cells

Streptococcus pneumoniae commonly resides asymptomatically in the nasopharyngeal (NP) cavity of healthy individuals but can cause life-threatening pulmonary and systemic infections, particularly in the elderly. NP colonization results in a robust immune response that protects against invasive infections. However, the duration, mechanism, and cellular component of such responses are poorly understood. In this study, we found that repeated NP exposure of mice to S. pneumoniae TIGR4 strain results in pneumococcal-specific Ab responses that protect against lethal lung challenge. Abs were necessary and sufficient for protection because Ab-deficient μMT mice did not develop postexposure protection, only becoming resistant to lung infection after transfer of immune sera from NP-exposed mice. T cells contributed to immunity at the time of NP exposure, but neither CD4⁺ nor CD8⁺ T cells were required. The protective activity was detectable 20 wk after exposure and was maintained in irradiated mice, suggesting involvement of long-lived Ab-secreting cells (ASC), which are radioresistant and secrete Abs for extended periods of time in the absence of T cells or persistent Ag. CD138⁺ bone marrow cells, likely corresponding to long-lived ASC, were sufficient to confer protection. NP exposure of aged mice failed to protect against subsequent lung infection despite eliciting a robust Ab response. Furthermore, transfer of CD138⁺ bone marrow cells or sera from NP-exposed old mice failed to protect naive young mice. These findings suggest that NP exposure elicits extended protection against pneumococcal lung infection by generating long-lived CD138⁺ ASC and that the protective efficacy of these responses declines with age.

Immunogenicity and persistence of a prime-boost re-vaccination strategy for pneumococcal vaccines in patients with rheumatoid arthritis

OBJECTIVES

Patients with rheumatoid arthritis (RA) are at an increased risk of Pneumococcal infections. Immunogenicity and persistence of a prime-boost revaccination strategy using 13-valent/23-valent anti-pneumococcal vaccines was evaluated in patients with RA treated by Methotrexate (MTX) and anti-TNF.

METHOD

Twenty-four patients with RA received one dose of PCV13 (Prevenar13®; Pfizer) followed two months later by one dose of PPV23 (Pneumovax®, Merck). Concentrations of IgG specific for 7 serotypes common to both vaccines and 3 uncommon serotypes, included only in the PPV23 were measured by ELISA and Opsonophagocytic Assay (OPA) at baseline and after 4, 12 and 24 months post-vaccine.

RESULTS

Similar percentages of protection were found at 4 months (63% vs. 55%), 12 months (54% vs. 50%) and 24 months (52% vs. 55%) for the 7 common and 3 uncommon serotypes when antibody titers were assayed by ELISA. Based on functional antibody measurements by OPA, a decrease of protected patients was observed 24 months after vaccine with only 19% of patients protected compared to 29% at baseline.

CONCLUSION

Although the combined pneumococcal revaccination strategy induces good protection in the short term in RA patients, this protection does not persist beyond two years with levels of functional antibody decreasing below pre-vaccine levels. We did not observe a higher efficacy of the conjugate vaccine compared to the polysaccharide vaccine. Our results clearly question the advantage of the prime-boost strategy as it highlight the possible hyporesponse induced by PPV23 against the immune response elicited by the primo-injection of the PCV13 vaccine.

La fragilidad no se asocia con una baja frecuencia de vacunación en adultos mayores

Señor editor: Los adultos mayores son particularmente susceptibles a infecciones respiratorias, por lo que la prevención de éstas es fundamental para disminuir complicaciones. Por otra parte, en geriatría, “fragilidad”describe un estado de gran vulnerabilidad y pobre resiliencia, el cual no debería excluir a las personas frágiles del beneficio de intervenciones tales como la vacunación, bajo el argumento infundado de que ésta es inútil.

Influenza vaccine response in community-dwelling German prefrail and frail individuals

Background

The age-related dysregulation of the immune system in older persons results in reduced responses to vaccination and greater susceptibility to infection, especially in frail individuals who suffer the greatest of morbidity and mortality due to infection. Recently, significantly reduced anti-influenza antibody titers and increased rates of influenza infection after vaccination were reported in community-dwelling American frail older adults. The aim of our study was to further assess the relative impact of frailty and of each individual Fried frailty criterion on influenza vaccine response. Prefrail and frail community-dwelling German persons aged ≥70 years were recruited for a nutritional randomized double-blind placebo-controlled clinical trial conducted during the 2014–2015 influenza season. Herein, we present a sub-analysis study of the placebo group to compare 76 prefrail and frail participants.

Results

Previous seasonal influenza vaccination rate was relatively high (77.6%) in the 76 volunteers aged from 70 to 93 years. Of these participants, 65.8% were diagnosed as prefrail and 34.2% as frail according to the Fried frailty criteria. In both prefrail and frail groups, elevated levels of pre-vaccination seroprotection were observed to all vaccine strains (H1N1: 54% and 32%, H3N2: 60% and 72%, B: 10% and 16%). Post-vaccination, similar increases in haemagglutination-inhibiting antibody titers were observed for the three vaccine strains in both prefrail and frail groups. No significant difference in geometric mean titer (GMT) ratios and in rates of seroconversion or seroprotection were observed between prefrail and frail groups. Regarding the five Fried frailty criteria, only participants with low physical activity had significantly lower GMT to the strains H3N2 (55.4 vs 103.7, p = 0.001) and B (13.9 vs 20.0, p = 0.06), as compared to those having normal physical activity.

Conclusions

Influenza vaccine response was not significantly affected by the frail phenotype, as defined by Fried frailty criteria, in community-dwelling German individuals. However, low physical activity may be a relevant predictor of lower serological response in vaccinated older individuals.

Trial registration

Clinicaltrials.govNCT02262091 (October 8, 2013).

A case series evaluating the serological response of adult asthma patients to the 23-valent pneumococcal polysaccharide vaccine

BACKGROUND

Asthma is an independent risk factor for invasive pneumococcal disease; however, the immune response of adult asthma patients to pneumococcal vaccination is unknown. We explore the serologic response of patients with moderate to severe asthma to the 23-valent pneumococcal polysaccharide vaccine (PPSV23).

METHODS

Seventeen moderate to severe adult asthma patients that had not been vaccinated against pneumococcus over the 5 previous years were prospectively recruited from a tertiary care asthma clinic. Serum was analyzed for the presence of antibodies to five capsular polysaccharide (CP) antigens (6B, 9V, 19A, 19F, 23F) before and 4 weeks after PPSV23 vaccination.

RESULTS

There was a wide variability in baseline anti-CP antibody concentrations. Other than for serotype 19A, our patients frequently have baseline anti-CP antibody concentrations below 1 µg/mL (35% for serotype 19F, 41% for serotypes 9V and 23F, and 59% for serotype 6B). All post-vaccination geometric mean antibody concentrations were significantly higher than baseline. In the 31 tests where the baseline antibody concentration was <1 µg/mL, 77.4% had at least a twofold increase post-vaccination. Despite this, a large proportion of post-vaccination anti-CP antibody concentrations remained <1 µg/mL (51.6% of tests). Nine patients had at least one anti-CP antibody concentration <1 µg/mL post-vaccination. There was no difference between these patients and the remaining eight patients in demographic or clinical variables.

CONCLUSIONS

Patients with moderate to severe asthma have variable baseline and low post-vaccination antibody concentrations to common CP antigens included in the PPSV23 vaccine. The clinical relevance of these observations remains to be determined since the threshold concentration in adults required for clinical protection from invasive pneumococcal disease is uncertain.

Preexisting Immunity, Not Frailty Phenotype, Predicts Influenza Postvaccination Titers among Older Veterans

Both preexisting immunity to influenza and age have been shown to be correlates of influenza vaccine responses. Frailty, an indicator of functional impairment in older adults, was also shown in one study to predict lower influenza vaccine responses among nonveterans. In the current study, we aimed to determine the associations between frailty, preexisting immunity, and immune responses to influenza vaccine among older veterans. We studied 117 subjects (age range, 62 to 95 years [median age, 81 years]), divided into three cohorts based on the Fried frailty test, i.e., nonfrail (NF) (n = 23 [median age, 68 years]), prefrail (n = 50 [median age, 80 years]), and frail (n = 44 [median age, 82 years]), during the 2010-2011 and 2011-2012 influenza seasons. Subjects received the seasonal trivalent inactivated influenza vaccine, and baseline and postvaccination samples were obtained. Anti-influenza humoral immunity, as measured by hemagglutination inhibition (HI) and microneutralization assays, was measured for influenza B, A(H1N1)pdm09, and A(H3N2) viruses. Postvaccination titers were not different between frail and NF subjects overall in this older subset of veterans. However, preexisting HI titers were strongly correlated with postvaccination titers among all functional status groups. When microneutralization titers were compared, the association between preexisting immunity and vaccine responses varied by frailty status, with the strongest correlation being observed for the NF group. In conclusion, preexisting immunity rather than frailty appeared to predict postvaccination titers in this older veteran cohort.

Economic Evaluation of Vaccination Programmes in Older Adults and the Elderly: Important Issues and Challenges

High-income countries are undergoing demographic transitions towards populations with substantial larger proportions of older adults. Due to the increased susceptibility of older adults to infectious diseases and their consequences, vaccination programmes are an important health intervention to help maintain healthy ageing. While much of the existing literature suggests that current vaccination programmes targeted at older adults and the elderly are likely to be cost effective in high-income countries, we argue that it is important to more fully consider some important issues and challenges. Since the majority of vaccines have been developed for children, economic evaluations of vaccination programmes have consequentially tended to focus on this age group and on how to incorporate herd-immunity effects. While programmes targeted at older adults and the elderly may also induce some herd effects, there are other important challenges to consider in these economic evaluations. For example, age and time effects in relation to vaccine efficacy and duration of immunity, as well as heterogeneity between targeted individuals in terms of risk of infection, severity of disease and response to vaccination. For some pathogens, there is also the potential for interactions with childhood programmes in the form of herd-immunity effects.

Should Committees That Write Guidelines and Recommendations Publish Dissenting Opinions?

Medical guidelines tend to convey a sense of unanimity of opinion that may not reflect the deliberations of the experts who wrote them. Using, as an example, an analysis of the recently published recommendations on administering pneumococcal conjugate vaccine to adults, the present article raises the question of whether official recommendations and guidelines should include dissenting opinions, analogous to decisions issued by the US Supreme Court. The argument that such a policy would lead to confusion in our profession is addressed in 2 ways: (1) the current system, in which different professional societies publish conflicting recommendations, as in the case of breast or prostate cancer screening, can be far more confusing, and (2) in the long run, greater transparency will lead to more thoughtful and higher-quality medical care. Perhaps the most important point of this paper is the suggestion that it is far better to bring dissent into the recommendation process than to act as if it is not there.

Evaluating the case-positive, control test-negative study design for influenza vaccine effectiveness for the frailty bias

INTRODUCTION

Previous influenza vaccine effectiveness studies were criticized for their failure to control for frailty. This study was designed to see if the test-negative study design overcomes this bias.

METHODS

Adults ≥ 50 years of age with respiratory symptoms were enrolled from November 2006 through May 2012 during the influenza season (excluding the 2009-2010 H1N1 pandemic season) to perform yearly test-negative control influenza vaccine effectiveness studies in Nashville, TN. At enrollment, both a nasal and throat swab sample were obtained and tested for influenza by RT-PCR. Frailty was calculated using a modified Rockwood Index that included 60 variables ascertained in a retrospective chart review giving a score of 0 to 1. Subjects were divided into three strata: non frail (≤ 0.08), pre-frail (> 0.08 to < 0.25), and frail (≥ 0.25). Vaccine effectiveness was calculated using the formula [1-adjusted odds ratio (OR)] × 100%. Adjusted ORs for individual years and all years combined were estimated by penalized multivariable logistic regression.

RESULTS

Of 1023 hospitalized adults enrolled, 866 (84.7%) participants had complete immunization status, molecular influenza testing and covariates to calculate frailty. There were 83 influenza-positive cases and 783 test-negative controls overall, who were 74% white, 25% black, and 59% female. The median frailty index was 0.167 (Interquartile: 0.117, 0.267). The frailty index was 0.167 (0.100, 0.233) for the influenza positive cases compared to 0.183 (0.133, 0.267) for influenza negative controls (p = 0.07). Vaccine effectiveness estimates were 55.2% (95%CI: 30.5, 74.2), 60.4% (95%CI: 29.5, 74.4), and 54.3% (95%CI: 28.8, 74.0) without the frailty variable, including frailty as a continuous variable, and including frailty as a categorical variable, respectively.

CONCLUSIONS

Using the case positive test negative study design to assess vaccine effectiveness, our measure of frailty was not a significant confounder as inclusion of this measure did not significantly change vaccine effectiveness estimates.

A review of economic evaluations of 13-valent pneumococcal conjugate vaccine (PCV13) in adults and the elderly

The 13-valent pneumococcal conjugated vaccine (PCV13) is already recommended for some adult groups and is being considered for wider use in many countries. In order to identify the strengths and limitations of the existing economic evaluation studies of PCV13 in adults and the elderly a literature review was conducted. The majority of the studies identified (9 out of 10) found that PCV13 was cost-effective in adults and/or the elderly. However, these results were based on assumptions that could not always be informed by robust evidence. Key uncertainties included the efficacy of PCV13 against non-invasive pneumonia and the herd immunity effect of childhood vaccination programs. Emerging trial evidence on PCV13 in adults from the Netherlands offers the ability to parameterize future economic evaluations with empirical efficacy data. However, it is important that these estimates are used thoughtfully when they are transferred to other settings.

Why the recent ACIP recommendations regarding conjugate pneumococcal vaccine in adults may be irrelevant

The Advisory Committee on Immunization Practices of the US Centers for Disease Control (ACIP) has recently recommended the 13-valent protein-conjugate pneumococcal vaccine (PCV13) for routine use in adults age 18-65 who have immunocompromising conditions as well as in all adults over the age of 65. By comparison to 23-valent pneumococcal polysaccharide vaccine (PPSV23), antibody responses to PCV13 are similar or modestly better one month after vaccination. The implication that PCV13 will provide more persistent immunity has been disproven; 12 months later, recipients of PPSV23 or PCV13 have identical anti-pneumococcal activity. The theoretical concept that a protein-based vaccine will be followed by a booster effect when pure polysaccharide antigens are administered is based on remarkably little evidence. The strongest objection to the current recommendations is that, since PCVs stimulate mucosal antibodies, the widespread use of these PCVs has led to a near-disappearance of vaccine serotypes from the population. This phenomenon has been amply documented for PCV7, and PCV13 is well on its way to doing the same. Thus, as US physicians are convincing their adult patients to receive 2 "pneumonia shots" instead of one, the use of PCV13 in the USA is rapidly becoming irrelevant.