Efficacy of pneumococcal vaccine in high-risk patients. Results of a Veterans Administration Cooperative Study

Cost-Effectiveness of 20-Valent Pneumococcal Conjugate Vaccine in Argentinean Adults

INTRODUCTION

In Argentina, vaccination with 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23; PCV13 → PPSV23) has been recommended for all adults aged ≥ 65 years and younger adults with chronic medical ("moderate-risk") or immunocompromising ("high-risk") conditions since 2017. With the approval of a 20-valent PCV (PCV20), we evaluated the cost-effectiveness of PCV20 versus current recommendations for moderate-/high-risk adults aged 18-64 years and all adults 65-99 years.

METHODS

A probabilistic cohort model was used to project lifetime outcomes and costs associated with invasive pneumococcal disease (IPD) and all-cause non-bacteremic pneumonia (NBP), and the expected impact of vaccination. Clinical outcomes were projected annually based on Argentinean data. Economic costs were estimated based on cases and corresponding medical costs (adjusted to 2023 USD) and costs of vaccine and administration. Cost-effectiveness of PCV20 was evaluated versus the current strategy, PCV13 → PPSV23, and alternatively, versus sequentially administered 15-valent PCV and PPSV23 (PCV15 →  PPSV23), and presented as cost per quality-adjusted life year gained; a healthcare system perspective was used. Costs and benefits were discounted at 3%/year.

RESULTS

PCV20 in lieu of PCV13 → PPSV23 among moderate-/high-risk adults aged 18-64 years and all adults 65-99 years (N = 13.4M) prevented 3838 IPD, 4377 inpatient NBP, and 6003 outpatient NBP cases, and 1865 disease-related deaths; relative to PCV15 → PPSV23 the corresponding reductions were 2775, 3285, 4518, and 1348. PCV20 was projected to be the dominant strategy versus PCV13 → PPSV23 and PCV15 → PPSV23 as overall costs were lower by $87.6M and $80.8M, respectively. In probabilistic sensitivity analyses, PCV20 was dominant (i.e., more effective, less costly) in 100% of 1000 simulations.

CONCLUSIONS

Analyses suggest implementing a PCV20 vaccination program in moderate-/high-risk adults aged 18-64 years and all adults ≥ 65 years-in lieu of PCV13 → PPSV23-would yield substantial reductions in pneumococcal disease and would be cost saving to the Argentinean healthcare system.

Cost-Effectiveness of 20-Valent Pneumococcal Conjugate Vaccine Among US Children with Underlying Medical Conditions

INTRODUCTION

A 20-valent pneumococcal conjugate vaccine (PCV20) was recently recommended for use among US children. We evaluated the cost-effectiveness of PCV20 among children aged 6 years with chronic medical conditions (CMC+) and children aged 6 years with immunocompromising conditions (IC) versus one and two doses of 23-valent pneumococcal polysaccharide vaccine (PPSV23), respectively.

METHODS

A probabilistic model was employed to depict 10-year risk of clinical outcomes and economic costs of pneumococcal disease, reduction in life years from premature death, and expected impact of vaccination among one cohort of children with CMC+ and IC aged 6 years. Vaccine uptake was assumed to be 20% for both PCV20 and PPSV23. Cost per quality-adjusted life year (QALY) gained was evaluated from the US societal and healthcare system perspectives; deterministic and probabilistic sensitivity analyses (DSA/PSA) were also conducted.

RESULTS

Among the 226,817 children with CMC+ aged 6 years in the US, use of PCV20 (in lieu of PPSV23) was projected to reduce the number cases of pneumococcal disease by 5203 cases, medical costs by US$8.7 million, and nonmedical costs by US$6.2 million. PCV20 was the dominant strategy versus PPSV23 from both the healthcare and societal perspectives. In the PSA, 99.9% of the 1000 simulations yielded a finding of dominance for PCV20. Findings in analyses of children with IC aged 6 years in the USA were comparable (i.e., PCV20 was the dominant vaccination strategy). Scenario analyses showed that increasing PCV20 uptake to 100% could potentially prevent > 22,000 additional cases of pneumococcal disease and further reduce medical and nonmedical costs by US$70.0 million among children with CMC+ and IC.

CONCLUSIONS

Use of PCV20 among young children with CMC+ and IC in the USA would reduce the clinical burden of pneumococcal disease and yield overall cost savings from both the US healthcare system and societal perspectives. Higher PCV20 uptake could further reduce the number of pneumococcal disease cases in this population.

Cost-effectiveness analysis of adult pneumococcal conjugate vaccines for pneumococcal disease in Japan

BACKGROUND

The 23-valent pneumococcal polysaccharide vaccine (PPSV23) is used in the Japanese National Immunization Program for older adults and adults with increased risk for pneumococcal disease, however, disease incidence and associated burden remain high. We evaluated the cost-effectiveness of pneumococcal conjugate vaccines (PCVs) for adults aged 65 years and high-risk adults aged 60-64 years in Japan.

RESEARCH DESIGN AND METHODS

Using a Markov model, we evaluated lifetime costs using societal and healthcare payer perspectives and estimated quality-adjusted life-years (QALYs), and number of prevented cases and deaths caused by invasive pneumococcal disease (IPD) and non-IPD. The base case analysis used a societal perspective.

RESULTS

In comparison with PPSV23, the 20-valent PCV (PCV20) prevented 127 IPD cases 10,813 non-IPD cases (inpatients: 2,461, outpatients: 8,352) and 226 deaths, and gained more QALYs (+0.0015 per person) with less cost (-JPY22,513 per person). All sensitivity and scenario analyses including a payer perspective analysis indicated that the incremental cost-effectiveness ratios (ICERs) were below the cost-effectiveness threshold value in Japan (JPY5 million/QALY).

CONCLUSIONS

PCV20 is both cost saving and more effective than PPSV23 for adults aged 65 years and high-risk adults aged 60-64 years in Japan.

Cost-effectiveness of using a 20-valent pneumococcal conjugate vaccine to directly protect adults in England at elevated risk of pneumococcal disease

OBJECTIVES

Despite the current pneumococcal vaccination program in England for older adults and adults with underlying conditions, disease burden remains high. We evaluated cost-effectiveness of 20-valent pneumococcal conjugate vaccine (PCV20) compared to current pneumococcal recommendations for adults in England.

METHODS

Lifetime outcomes/costs of invasive pneumococcal disease (IPD) and community-acquired pneumonia (CAP) among adults aged 65-99 years and adults aged 18-64 years with underlying conditions in England were projected using a probabilistic cohort model. Vaccination with PCV20 was compared with 23-valent pneumococcal polysaccharide vaccine (PPV23) from the National Health Service perspective.

RESULTS

PCV20 was cost saving compared with PPV23 in base case and most sensitivity analyses. In the base case, replacing PPV23 with PCV20 prevented 7,789 and 140,046 cases of IPD and hospitalized CAP, respectively, and 22,199 associated deaths, resulting in incremental gain of 91,375 quality-adjusted life-years (QALYs) and incremental savings of £160M. In probabilistic sensitivity analyses, PCV20 (vs. PPV23) was cost saving in 85% of simulations; incremental cost per QALY was below £30,000 in 99% of simulations.

CONCLUSIONS

PCV20 vaccination in adults aged 65-99 years and those aged 18-64 years with underlying comorbidities in England is expected to prevent more hospitalizations, save more lives, and yield lower overall costs than current recommendations for PPV23.

The remarkable history of pneumococcal vaccination: an ongoing challenge

Although it varies with age and geographical distribution, the global burden of infection with Streptococcus pneumoniae (pneumococcus) remains considerable. The elderly, and younger adults with comorbid conditions, are at particularly high risk of pneumococcal infection, and this risk will increase as the population ages. Vaccination should be the backbone of our current strategies to deal with this infection.

Main body: This manuscript reviews the history of the development of pneumococcal vaccines, and the impact of different vaccines and vaccination strategies over the past 111 years. It documents the early years of vaccine development in the gold mines of South Africa, when vaccination with killed pneumococci was shown to be effective, even before the recognition that different pneumococci were antigenically distinct. The development of type-specific vaccines, still with whole killed pneumococci, showed a high degree of efficacy. The identification of the importance of the pneumococcal capsule heralded the era of vaccination with capsular polysaccharides, although with the advent of penicillin, interest in pneumococcal vaccine development waned. The efforts of Austrian and his colleagues, who documented that despite penicillin therapy, patients still died from pneumococcal infection in the first 96 h, ultimately led to the licensing first of a 14-valent pneumococcal polysaccharide in 1977 followed by the 23-valent pneumococcal polysaccharide in 1983. The principal problem with these, as with other polysaccharide vaccines, was that that they failed to immunize infants and toddlers, who were at highest risk for pneumococcal disease. This was overcome by chemical linking or conjugation of the polysaccharide molecules to an immunogenic carrier protein. Thus began the era of pneumococcal conjugate vaccine (PCV), starting with PCV7, progressing to PCV10 and PCV13, and, most recently, PCV15 and PCV20. However, these vaccines remain serotype specific, posing the challenge of new serotypes replacing vaccine types. Current research addresses serotype-independent vaccines which, so far, has been a challenging and elusive endeavor.

Conclusion: While there has been enormous progress in the development of pneumococcal vaccines during the past century, attempts to develop a vaccine that will retain its efficacy for most pneumococcal serotypes are ongoing.

Public health and budgetary impact of 20-valent pneumococcal conjugate vaccine for adults in England

BACKGROUND

. Despite use of 23-valent pneumococcal polysaccharide vaccine (PPV23) in England, disease burden among at-risk adults remains high. We evaluated the public health and budgetary impact of 20-valent pneumococcal conjugate vaccine (PCV20) compared to the current adult pneumococcal vaccination program.

METHODS

Five-year outcomes and costs of invasive pneumococcal disease (IPD) and community-acquired pneumonia (CAP) among adults aged 65-99 years and adults aged 18-64 years with underlying conditions in England were projected using a deterministic cohort model. Hypothetical vaccination with PCV20 versus PPV23 was compared from National Health Service (NHS) perspective.

RESULTS

Replacing PPV23 with PCV20 would prevent 785 IPD hospitalizations, 11,751 CAP hospitalizations, and 1,414 deaths over five years, and would reduce medical care costs by £48.5M. With vaccination costs higher by £107.2M, projected net budgetary impact is £58.7M. The budgetary impact would be greatest in year one (£26.3M), and would decrease over time (to £1.6M by year five). The average budget increase (£11.7M/year) represents <0.01% of the Department of Health and Social Care budget and <3% of the vaccines budget.

CONCLUSIONS

Use of PCV20 among adults currently eligible for PPV23 in England would substantially reduce the burden of pneumococcal disease, with modest budgetary impact.

Alternative Complement Pathway Inhibition Abrogates Pneumococcal Opsonophagocytosis in Vaccine-Naïve, but Not in Vaccinated Individuals

To assess the relative contribution of opsonisation by antibodies, classical and alternative complement pathways to pneumococcal phagocytosis, we analyzed killing of pneumococci by human blood leukocytes collected from vaccine-naïve and PCV13-vaccinated subjects. With serotype 4 pneumococci as model, two different physiologic opsonophagocytosis assays based on either hirudin-anticoagulated whole blood or on washed cells from EDTA-anticoagulated blood reconstituted with active serum, were compared. Pneumococcal killing was measured in the presence of inhibitors targeting the complement components C3, C5, MASP-2, factor B or factor D. The two assay formats yielded highly consistent and comparable results. They highlighted the importance of alternative complement pathway activation for efficient opsonophagocytic killing in blood of vaccine-naïve subjects. In contrast, alternative complement pathway inhibition did not affect pneumococcal killing in PCV13-vaccinated individuals. Independent of amplification by the alternative pathway, even low capsule-specific antibody concentrations were sufficient to efficiently trigger classical pathway mediated opsonophagocytosis. In heat-inactivated or C3-inhibited serum, high concentrations of capsule-specific antibodies were required to trigger complement-independent opsonophagocytosis. Our findings suggest that treatment with alternative complement pathway inhibitors will increase susceptibility for invasive pneumococcal infection in non-immune subjects, but it will not impede pneumococcal clearance in vaccinated individuals.

Efficacy and effectiveness of a 23-valent polysaccharide vaccine against invasive and noninvasive pneumococcal disease and related outcomes: a review of available evidence

Introduction: Routine pneumococcal vaccination for adults aged ≥60 or ≥65 years and those with underlying at-risk and high-risk conditions is recommended in many countries. However, studies estimating the effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPSV23) have revealed mixed results, partly due to variability in study design and endpoints used to assess outcomes.Areas covered: The authors conducted a literature review of independently randomized trials and real-world studies published from 2010 to 2020 that assessed the effectiveness and efficacy of PPSV23 against vaccine-type or any-serotype invasive and noninvasive pneumococcal disease in adults aged ≥60 years. The authors also evaluated differences in study design that may contribute to the heterogeneity of available evidence.Expert opinion: Policy decisions regarding the inclusion of vaccines into national immunization plans should consider study quality and limitations. This review shows that PPSV23 is effective against vaccine-type invasive pneumococcal disease and vaccine-type pneumococcal pneumonia and can lower the burden of vaccine-type pneumococcal pneumonia. PPSV23-conferred protection may be lower in adults aged ≥75 years, those with certain underlying conditions, and individuals who were vaccinated >5 years before disease onset. This is an important finding that supports the benefit of PPSV23 vaccination for older adults.

SLy2-deficiency promotes B-1 cell immunity and triggers enhanced production of IgM and IgG2 antibodies against pneumococcal vaccine

Background

Despite the benefits of existing vaccines, Streptococcus pneumoniae is still responsible for the greatest proportion of respiratory tract infections around the globe, thereby substantially contributing to morbidity and mortality in humans. B‐1 cells are key players of bacterial clearance during pneumococcal infection and even provide long‐lasting immunity towards S. pneumoniae. Previous reports strongly suggest an essential role of the immunoinhibitory adapter Src homology domain 3 lymphocyte protein 2 (SLy2) for B‐1 cell‐mediated antibody production. The objective of this study is to evaluate S. pneumoniae‐directed B cell responses in the context of SLy2 deficiency.

Methods

B‐1 cell populations were analyzed via flow cytometry before and after pneumococcal immunization of SLy2‐deficient and wild‐type control mice. Global and vaccine‐specific immunoglobulin M (IgM) and IgG antibody titers were assessed by enzyme‐linked immunosorbent assay. To investigate survival rates during acute pneumococcal lung infection, mice were intranasally challenged with S. pneumoniae (serotype 3). Complementary isolated splenic B cells were stimulated in vitro and their proliferative response was assessed by fluorescent staining. In vitro antibody secretion was quantified by LEGENDplex.

Results

We demonstrate increased frequencies of B‐1 cells and elevated titers of preantigenic IgM in SLy2‐deficient mice. In addition, these mice produce significantly more amounts of IgM and IgG₂ upon pneumococcal vaccination. Knocking out SLy2 did not induce survival advantages in our murine model of acute pneumonia, indicating the presence of compensatory mechanisms.

Conclusion

Our results reveal reinforced specific antibody responses towards pneumococcal polysaccharides and enhanced IgG₂ secretion as a consequence of SLy2 deficiency, which could be relevant to the development of more efficient vaccines.

Vaccines to Prevent Pneumococcal Community-Acquired Pneumonia

Streptococcus pneumoniae is the most frequent pathogen in community-acquired pneumonia and also causes invasive diseases like bacteremia and meningitis. Young children and elderly are especially at risk for pneumococcal diseases and are, therefore, eligible for pneumococcal vaccination in most countries. This reviews provides an overview of the current epidemiology of pneumococcal infections, history and evidence of available pneumococcal polysaccharide and conjugate vaccines, and current recommendations.

Older Human B Cells and Antibodies

B cells have a number of different roles in the immune response. Their excellent antigen presentation potential can contribute to the activation of other cells of the immune system, and evidence is emerging that specialized subsets of these cells, that may be increased with age, can influence the cell-mediated immune system in antitumor responses. They can also regulate immune responses, to avoid autoreactivity and excessive inflammation. Deficiencies in regulatory B cells may be beneficial in cancer but will only exacerbate the inflammatory environment that is a hallmark of aging. The B cell role as antibody producers is particularly important, since antibodies perform numerous different functions in different environments. Although studying tissue responses in humans is not as easy as in mice, we do know that certain classes of antibodies are more suited to protecting the mucosal tissues (IgA) or responding to T-independent bacterial polysaccharide antigens (IgG₂) so we can make some inference with respect to tissue-specific immunity from a study of peripheral blood. We can also make inferences about changes in B cell development with age by looking at the repertoire of different B cell populations to see how age affects the selection events that would normally occur to avoid autoreactivity, or increase specificity, to antigen.

Decision-making for PCV in adults

Thirteen-valent pneumococcal conjugate vaccine (PCV13) was licensed in adults to address the unmet medical need of vaccine-type community acquired pneumonia (CAP) and the limitations of previous plain-polysaccharide vaccines. Since then, some have questioned the utility of adult PCV13 use, arguing that: i) high PCV13 uptake in young children would provide indirect effects that, by themselves, would sufficiently protect unvaccinated adults and ii) no data describing the real-world effectiveness of PCV13 use in adults, especially with immunocompromising conditions, exist. Even in countries like the United States where PCV13 has been routinely recommended for all adults aged ≥ 65 years, the recommendation is contingent on a re-evaluation to determine if continued use is needed in the context of a mature PCV13 pediatric immunization program. Emerging evidence, however, suggests that i) a meaningful burden of PCV13-type pneumococcal pneumonia still persists in adults at increased risk for pneumococcal disease, despite indirect effects from long-standing pediatric PCV13 use, ii) adult PCV13 use is effective and has reduced pneumococcal CAP, even in the elderly and those with chronic medical or immunocompromising conditions – and disease could come back if PCV13 were removed, and iii) ethical and pragmatic vaccine policy considerations support continued adult PCV13 use in countries that have already introduced the vaccine (eg, disparities in adult PCV13 uptake, confusion stemming from removing a previously-recommended vaccine for a non-safety-related concern, and the reality that next-generation PCVs are only a few years away). Together, these findings suggest that continued PCV13 vaccination in adults is needed to control vaccine-type CAP.

Estimating the cost-effectiveness of a sequential pneumococcal vaccination program for adults in Germany

Introduction

In Germany, a 23-valent polysaccharide pneumococcal vaccine (PPSV23) is recommended for elderly (60+) and patients 16+ with chronic diseases not associated with immune suppression. For all other patients at risk, sequential immunization with a 13-valent pneumococcal conjugate vaccine (PCV13) first, followed by PPSV23 is recommended. Repeated vaccination with PPSV23 is recommended every 6 years after individual assessment by the physician. This was adopted into the vaccination directive with binding reimbursement and funding. However, additional voluntary services allow statutory health insurances to differentiate from each other. Aim of this study is to estimate the cost-effectiveness of voluntary service scenarios compared to the strategy in place to support informed decision making.

Methods

A microsimulation framework with Markov-type process of a population susceptible to pneumococcal disease over a lifetime horizon was developed to compare effectiveness and cost-effectiveness of different vaccination strategies. We simulated 1,000 iterations for seven scenarios. Assumptions were derived from published literature and probabilistic sensitivity analysis was run to show the robustness of the model.

Results

Our study indicates that all voluntary service strategies could prevent further clinical cases compared to the existing policy. Depending on the scenario, 48–142 invasive pneumococcal disease (IPD), 24,000–45,000 hospitalized all-cause nonbacteremic pneumonia (NBP), 15,000–45,000 outpatient NBP cases, and 4,000–8,000 deaths could be avoided on average. This refers to potential savings of €115 Mio. - €187 Mio. for medical and non-medical costs. Additional costs per patient for the payer are €2.48 to €7.13 and for the society €2.20 to €6.85. The ICER per LYG ranged from €3,662 to €23,061 (payer) and €3,258 to €29,617 (societal). All but one scenario was cost-effective in ≥60% of the generated 1,000 simulations.

Conclusion

Compared to the vaccination strategy in place, the different hypothetical scenarios can be considered cost-effective and suitable as additional voluntary services.

Accuracy of composite diagnostic standards for pneumococcal pneumonia in vaccine trials

Because of a lack of gold standard diagnostics, a combination of multiple diagnostic tests, or composite diagnostic standard, has been used to measure pneumococcal pneumonia (PP) in pneumococcal vaccine trials. We estimated the accuracy of composite diagnostic standards for PP used in previous randomised controlled trials by simple formulas. A systematic literature review identified five eligible trials and all trials had used different combinations of diagnostic tests for PP. The estimated values of sensitivity and minimum specificity of composite diagnostic standards varied substantially between trials: 48.4% to 98.1% and 71.0% to 97.3%, respectively. Without standardizing the outcome measurements, pneumococcal vaccine efficacy estimates against PP are not comparable between trials and their pooled estimates are biased.

Pneumococcal conjugate vaccine use for the prevention of pneumococcal disease in adults <50 years of age

INTRODUCTION

Adults, particularly those with underlying chronic conditions, eg, cardiovascular, liver, and pulmonary diseases and diabetes mellitus, have a persistent pneumococcal disease burden. Thirteen-valent pneumococcal conjugate vaccine (PCV13) is recommended in the United States for all adults aged ≥65 years and immunocompromised adults aged <65 years to protect against vaccine-serotype (VT) invasive pneumococcal disease (IPD) and pneumonia. PCV13 is not recommended for immunocompetent adults aged ≥18 years with comorbidities associated with increased pneumococcal disease risk.

AREAS COVERED

This US-focused review summarizes PCV13-type IPD and community-acquired pneumonia burden in adults aged <50 years, PCV13 immunogenicity and safety in this population, and adult pneumococcal vaccination recommendations.

EXPERT COMMENTARY

Considering (i) PCV13 has demonstrated efficacy against VT-IPD and pneumonia in adults aged ≥65 years (with or without underlying chronic conditions), and (ii) immune responses to PCV13 in younger adults are comparable or better than in older adults, PCV13 would likely have similar efficacy in adults aged <50 years. Recommending PCV13 for at-risk adults aged <50 years would provide direct immunologic benefit of a conjugate vaccine and could address an important unmet medical need for pneumococcal pneumonia prevention. Although not directly addressed here, this benefit would likely extend to at-risk adults aged 50-64 years.

Rethinking number-needed-to-vaccinate for pneumococcal conjugate vaccines in older adults: Current and future implications

BACKGROUND

Number-needed-to-vaccinate (NNV) is increasingly used to inform decisions about vaccine use, but it is not calculated uniformly across studies. This study compared two methodologies for calculating NNV with 13-valent pneumococcal conjugate vaccine (PCV13) to prevent one case of community-acquired pneumonia (CAP) among US adults aged ≥65years: (i) using one-year absolute rate differences as was originally performed by the Centers for Disease Control and Prevention (CDC) and (ii) using absolute risk reduction over 5years.

METHODS

We constructed a hypothetical fixed cohort of 200,000 adults aged ≥65years equally separated into PCV13-vaccinated and PCV13-unvaccinated groups. We incorporated the same conservative assumptions used by CDC in 2014 regarding annual incidence of hospitalized (1375 per 100,000) and outpatient (2010 per 100,000) CAP, the initial (2014) proportion of adult PCV13-type CAP (10%), and PCV13 efficacy against vaccine-type CAP (45%). To model PCV13 impact over time, we assumed annual mortality was 5% for both groups, the percentage of adult PCV13-type CAP declined annually due to pediatric herd effects, and PCV13 efficacy did not wane over 5years.

RESULTS

Among adults aged ≥65years, NNV with PCV13 to prevent one hospitalized and one outpatient case of CAP as originally calculated by CDC in 2014 were 1620 and 1110, respectively. Accounting for 5-year cumulative effects, NNV with PCV13 to prevent one hospitalized and one outpatient case of CAP over 5years were 576 and 394, respectively. These revised NNV estimates are roughly one third of initial estimates in which cumulative effects were ignored. NNV to prevent any CAP (inpatient or outpatient) over 5years with one PCV13 dose was 234.

CONCLUSION

Accounting for cumulative preventive effects of PCV13 vaccination over time is critical. Failing to do so, even when using conservative disease burden parameters, can grossly underestimate the public health impact of adult PCV13 use.

Primary prevention in the intensive care unit: a prospective single-centre study of the risk factors for invasive pneumococcal disease

Invasive pneumococcal disease is a significant health burden in Australia, with immunisation recommended for children and at-risk adults. Health benefits of immunisation are clear, but less effective when immunisation rates are low, as in Western Australia. We hypothesised that patients admitted unplanned to the intensive care unit (ICU) would have high eligibility for pneumococcal immunisation, but low rates of recorded vaccine administration. We performed a prospective observational study of 119 emergency admissions to Royal Perth ICU, a 20-bed mixed ICU at a tertiary teaching hospital in Western Australia. Each admission was screened for vaccine eligibility (age and risk factors as per Australian Technical Advisory Group of Immunisation guidelines), with patients' health records examined and primary care providers contacted after ICU discharge. Risk factors for invasive pneumococcal disease were common, with 52% of the study population having one or more. Fifty-four of 119 admitted patients (45%) were assessed as eligible for immunisation after ICU discharge. ICU survivors represent a high-risk population for which intervention against modifiable targets, such as invasive pneumococcal disease, may reduce both their chronic health burden and future health expenditure. Future efforts should concentrate on assessing the feasibility of a screening program for modifiable factors in ICU survivors, and the logistics of delivering these interventions in a timely manner during their hospital stay.

Survey of vaccination practices in patients with diabetes: A report examining patient and provider perceptions and barriers

In a cross-sectional study involving 279 patients with diabetes attending a primary care center the proportion of patients vaccinated for seasonal influenza, pneumococcus and hepatitis B was 40%, 2% and 2%, respectively. We found significant barriers for vaccination in 24% of patients and in 42% of providers.

Pneumococcal conjugate vaccine use in adults - Addressing an unmet medical need for non-bacteremic pneumococcal pneumonia

Streptococcus pneumoniae is a frequent cause of community acquired pneumonia (CAP), with the largest burden of disease attributed to non-bacteremic pneumonia. Due to the high persistent burden of disease, pneumococcal pneumonia, particularly non-bacteremic pneumococcal pneumonia, continues to be a major public health concern. There are currently two pneumococcal vaccines approved for use in adults in the United States (US) and other countries worldwide: a 23-valent pneumococcal simple polysaccharide vaccine (PPV23), and a 13-valent pneumococcal conjugate vaccine (PCV13). The capsular polysaccharides included in PPV23 induce antibodies primarily by a T-cell independent mechanism, thus the immune response is short lived and lacks the ability to elicit an anamnestic response. PCV13, on the other hand, has the bacterial polysaccharides covalently conjugated to an immunogenic carrier protein resulting in the formation of memory B lymphocytes, thus proving long-acting immunologic memory and an anamnestic response. Despite 30years of use, the question of PPV23 vaccine efficacy, particularly with respect to efficacy for non-bacteremic pneumonia, has been extensively debated and investigated; whereas PCV13 efficacy against vaccine-type pneumococcal CAP, both bacteremic and non-bacteremic, was confirmed in a large randomized controlled trial in older adults. PCV13 was approved under the US Food and Drug Administration's accelerated pathway, which allows for earlier approval of products that provide meaningful benefit over existing treatments - in this case, protection of adults from non-bacteremic pneumococcal pneumonia. Its use is now increasingly recommended globally. This article summarizes the history and use of PPV23 and PCV13 in adults and how vaccination of adults with PCV13 addresses an unmet medical need.

Pneumococcal vaccines for preventing pneumonia in chronic obstructive pulmonary disease

BACKGROUND

People with chronic obstructive pulmonary disease (COPD) are at increased risk of pneumococcal disease, especially pneumonia, as well as acute exacerbations with associated morbidity and healthcare costs.

OBJECTIVES

To determine the efficacy of injectable pneumococcal vaccination for preventing pneumonia in persons with COPD.

SEARCH METHODS

We searched the Cochrane Airways COPD Trials Register and the databases CENTRAL, MEDLINE and Embase, using prespecified terms. Searches are current to November 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCT) comparing injectable pneumococcal polysaccharide vaccine (PPV) or pneumococcal conjugated vaccine (PCV) versus a control or alternative vaccine type in people with COPD.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. For meta-analyses, we subgrouped studies by vaccine type.

MAIN RESULTS

For this update, we added five studies (606 participants), meaning that the review now includes a total of 12 RCTs involving 2171 participants with COPD. Average age of participants was 66 years, male participants accounted for 67% and mean forced expiratory volume in one second (FEV1) was 1.2 L (five studies), 54% predicted (four studies). We assessed risks of selection, attrition and reporting bias as low, and risks of performance and detection bias as moderate.Compared with control, the vaccine group had a lower likelihood of developing community-acquired pneumonia (CAP) (odds ratio (OR) 0.62, 95% confidence interval (CI) 0.43 to 0.89; six studies, n = 1372; GRADE: moderate), but findings did not differ specifically for pneumococcal pneumonia (Peto OR 0.26, 95% CI 0.05 to 1.31; three studies, n = 1158; GRADE: low). The number needed to treat for an additional beneficial outcome (NNTB) (preventing one episode of CAP) was 21 (95% CI 15 to 74). Mortality from cardiorespiratory causes did not differ between vaccine and control groups (OR 1.07, 95% CI 0.69 to 1.66; three studies, n = 888; GRADE: moderate), nor did all-cause mortality differ (OR 1.00, 95% CI 0.72 to 1.40; five studies, n = 1053; GRADE: moderate). The likelihood of hospital admission for any cause, or for cardiorespiratory causes, did not differ between vaccine and control groups. Vaccination significantly reduced the likelihood of a COPD exacerbation (OR 0.60, 95% CI 0.39 to 0.93; four studies, n = 446; GRADE: moderate). The NNTB to prevent a patient from experiencing an acute exacerbation was 8 (95% CI 5 to 58). Only one study (n = 181) compared the efficacy of different vaccine types - 23-valent PPV versus 7-valent PCV - and reported no differences for CAP, all-cause mortality, hospital admission or likelihood of a COPD exacerbation, but investigators described a greater likelihood of some mild adverse effects of vaccination with PPV-23.

AUTHORS' CONCLUSIONS

Injectable polyvalent pneumococcal vaccination provides significant protection against community-acquired pneumonia, although no evidence indicates that vaccination reduced the risk of confirmed pneumococcal pneumonia, which was a relatively rare event. Vaccination reduced the likelihood of a COPD exacerbation, and moderate-quality evidence suggests the benefits of pneumococcal vaccination in people with COPD. Evidence was insufficient for comparison of different pneumococcal vaccine types.

Pneumococcal Vaccination Strategies. An Update and Perspective

Streptococcus pneumoniae is an important global pathogen that causes a wide range of clinical disease in children and adults. Pneumococcal pneumonia is by far the common presentation of noninvasive and invasive pneumococcal disease and affects the young, the elderly, and the immunocompromised disproportionately. Patients with chronic pulmonary diseases are also at higher risk for pneumococcal infections. Substantial progress over the century has been made in the understanding of pneumococcal immunobiology and the prevention of invasive pneumococcal disease through vaccination. Currently, two pneumococcal vaccines are available for individuals at risk of pneumococcal disease: the 23-valent pneumococcal polysaccharide vaccine (PPV23) and the 13-valent pneumococcal protein-conjugate vaccine (PCV13). The goal of pneumococcal vaccination is to stimulate effective antipneumococcal antibody and mucosal immunity response and immunological memory. Vaccination of infants and young children with pneumococcal conjugate vaccine has led to significant decrease in nasal carriage rates and pneumococcal disease in all age groups. Recent pneumococcal vaccine indication and schedule recommendations on the basis of age and risk factors are outlined in this Focused Review. As new pneumococcal vaccine recommendations are being followed, continued efforts are needed to address the vaccine efficacy in the waning immunity of the ever-aging population, the implementation of vaccines using two different vaccines under very specific schedules and their real world clinical and cost effectiveness, and the development of next generation pneumococcal vaccines.

Pneumococcal Vaccination in High-Risk Individuals: Are We Doing It Right?

Controversy exists regarding the optimal use of the 23-valent pneumococcal conjugate vaccine for the protection of high-risk individuals, such as children and adults with immunocompromising conditions and the elderly. The effectiveness and immunogenicity of 23-valent pneumococcal polysaccharide vaccine (PPV23) are limited in such high-risk populations compared to the healthy, with meta-analyses failing to provide robust evidence on vaccine efficacy against invasive pneumococcal disease (IPD) or pneumonia. Moreover, several studies have demonstrated a PPV23-induced state of immune tolerance or hyporesponsiveness to subsequent vaccination, where the response to revaccination does not reach the levels achieved with primary vaccination. The clinical significance of hyporesponsiveness is not yet clarified, but attenuated humoral and cellular response could lead to reduced levels of protection and increased susceptibility to pneumococcal disease. As disease epidemiology among high-risk groups shows that we are still in need of maximum serotype coverage, the optimal use of PPV23 in the context of combined conjugate/polysaccharide vaccine schedules is an important priority. In this minireview, we discuss PPV23-induced hyporesponsiveness and its implications in designing highly effective vaccination schedules for the optimal protection for high-risk individuals.

The Saudi Thoracic Society pneumococcal vaccination guidelines-2016

Streptococcus pneumoniae (pneumococcus) is the leading cause of morbidity and mortality worldwide. Saudi Arabia is a host to millions of pilgrims who travel annually from all over the world for Umrah and the Hajj pilgrimages and are at risk of developing pneumococcal pneumonia or invasive pneumococcal disease (IPD). There is also the risk of transmission of S. pneumoniae including antibiotic resistant strains between pilgrims and their potential global spread upon their return. The country also has unique challenges posed by susceptible population to IPD due to people with hemoglobinopathies, younger age groups with chronic conditions, and growing problem of antibiotic resistance. Since the epidemiology of pneumococcal disease is constantly changing, with an increase in nonvaccine pneumococcal serotypes, vaccination policies on the effectiveness and usefulness of vaccines require regular revision. As part of the Saudi Thoracic Society (STS) commitment to promote the best practices in the field of respiratory diseases, we conducted a review of S. pneumoniae infections and the best evidence base available in the literature. The aim of the present study is to develop the STS pneumococcal vaccination guidelines for healthcare workers in Saudi Arabia. We recommend vaccination against pneumococcal infections for all children <5 years old, adults ≥50 years old, and people ≥6 years old with certain risk factors. These recommendations are based on the presence of a large number of comorbidities in Saudi Arabia population <50 years of age, many of whom have risk factors for contracting pneumococcal infections. A section for pneumococcal vaccination before the Umrah and Hajj pilgrimages is included as well.

Pneumococcal Disease Prevention Among Adults: Strategies for the Use of Pneumococcal Vaccines

Use of the pneumococcal conjugate vaccines among children in the U.S. since 2000 has dramatically reduced pneumococcal disease burden among adults. Significant vaccine-preventable morbidity and mortality from pneumococcal infections still remains, especially among older adults. The U.S. Advisory Committee on Immunization Practices (ACIP) has recently recommended the routine use of both pneumococcal conjugate (PCV13) and polysaccharide vaccines (PPSV23) for adults ≥65 years. These recommendations were based on the remaining burden of illness among adults and the importance of non-bacteremic pneumonia prevention in light of new evidence confirming the efficacy of PCV13 to prevent pneumococcal pneumonia among older adults. This paper reviews the evidence that led ACIP to make recommendations for PCV13 and PPSV23 use among adults, and highlights potential gaps to be addressed by future studies to inform adult vaccination policy. The changing epidemiology of invasive pneumococcal disease and pneumonia should be closely monitored to evaluate the effectiveness and continued utility of the current vaccination strategy, and to identify future directions for pneumococcal disease prevention among older adults.

[Pneumococcal vaccines. New conjugate vaccines for adults]

Pneumococcal infections are a significant cause of morbidity and mortality, and are one of the 10 leading causes of death worldwide. Children under 2 years have a higher incidence rate, followed by adults over 64 years. The main risk group are individuals with immunodeficiency, and those with anatomical or functional asplenia, but can also affect immunocompetent persons with certain chronic diseases. Significant progress has been made in the last 10 years in the prevention of these infections. Until a few years ago, only the 23-valent non-conjugate pneumococcal vaccine was available. Its results were controversial in terms of efficacy and effectiveness, and with serious limitations on the type of immune response induced. The current possibility of using the 13-valent conjugate vaccine in adults has led to greater expectations in improving the prevention of pneumococcal disease in these age groups.

Pneumococcal disease prevention among adults: Strategies for the use of pneumococcal vaccines

Use of the pneumococcal conjugate vaccines among children in the US since 2000 has dramatically reduced pneumococcal disease burden among adults. Significant vaccine-preventable morbidity and mortality from pneumococcal infections still remains, especially among older adults. The US Advisory Committee on Immunization Practices (ACIP) has recently recommended the routine use of both pneumococcal conjugate (PCV13) and polysaccharide vaccines (PPSV23) for adults ≥65 years. These recommendations were based on the remaining burden of illness among adults and the importance of non-bacteremic pneumonia prevention in light of new evidence confirming the efficacy of PCV13 to prevent pneumococcal pneumonia among older adults. This paper reviews the evidence that led the ACIP to make recommendations for PCV13 and PPSV23 use among adults, and highlights potential gaps to be addressed by future studies to inform adult vaccination policy. The changing epidemiology of invasive pneumococcal disease and pneumonia should be closely monitored to evaluate the effectiveness and continued utility of the current vaccination strategy, and to identify future directions for pneumococcal disease prevention among older adults.

Effect of the adult pneumococcal polysaccharide vaccine on cardiovascular disease: a systematic review and meta-analysis

Animal models and clinical studies suggest a mechanistic link between the pneumococcal polysaccharide vaccine (PPV) and a cardiovascular protective effect. However, conflicting results exist from several large observational studies in humans. We set out to systematically review current literature and conduct meta-analyses of studies on PPV and cardiovascular outcomes. Medline, Embase and CENTRAL were searched for randomised controlled trials (RCTs) and observational studies in adults, using PPV as the intervention, up to 30 April 2014. Studies that compared PPV with a control (another vaccine, no vaccine or placebo) and recorded ischaemic events were included in this review. Two investigators extracted data independently on study design, baseline characteristics and summary outcomes. Study quality was examined using the Newcastle-Ottawa Quality Assessment Scale. Pooled estimates using random effects models and their 95% CIs were calculated separately for the outcomes of acute coronary syndrome (ACS) events and stroke. No RCT data were available. A total of 230 426 patients were included in eight observational studies and recorded as ACS events. PPV was associated with significantly lower odds of ACS events in patients 65 years and older (pooled OR=0.83 (95% CI 0.71 to 0.97), I(2)=77.0%). However, there was no significant difference in ACS events when younger people were included (pooled OR=0.86 (95% CI 0.73 to 1.01), I(2)=81.4%). Pooling of four studies, covering a total of 192 210 patients, did not find a significantly reduced risk of stroke in all patients (pooled OR=1.00 (95% CI 0.89 to 1.12), I(2)=55.3%), or when restricted to those 65 years and older (pooled OR=0.96 (95% CI 0.87 to 1.05), I(2)=22.5%). In this meta-analysis of observational studies, the use of PPV was associated with a significantly lower risk of ACS events in the older population, but not stroke. An adequately powered and blinded RCT to confirm these findings is warranted.

Pneumococcal polysaccharide vaccination in rheumatoid arthritis patients receiving tacrolimus

Introduction

In rheumatoid arthritis (RA) patients receiving immunosuppressive treatments, vaccination against Streptococcus pneumoniae is recommended. The objective of the study was to evaluate the effects of tacrolimus (TAC) on immune response following administration of a 23-valent pneumococcal polysaccharide vaccine (PPSV23) in patients with established RA.

Methods

Patients with RA (n = 133) were vaccinated with PPSV23. Patients were classified into TAC (n = 29), methotrexate (MTX) (n = 55), control (n = 35), and TAC/MTX (n = 14) treatment groups. We measured the concentrations of pneumococcal serotypes 6B and 23F by using an enzyme-linked immunosorbent assay and determined antibody functionality by using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI), before and 4 to 6 weeks after vaccination. A positive antibody response was defined as at least a twofold increase in the IgG concentration or as at least a 10-fold increase in the OI.

Results

IgG concentrations and OIs were significantly increased in all treatment groups after PPSV23 vaccination. The TAC treatment group appears to respond in a manner similar to that of the RA control group in terms of 6B and 23F serotype concentration and function. In contrast, the MTX group had the lowest immune response. Patients who received a combination of TAC and MTX (TAC/MTX) also had a diminished immune response compared with those who received TAC alone.

Conclusions

TAC monotherapy does not appear to impair PPSV23 immunogenicity in patients with RA, whereas antibody production and function may be reduced when TAC is used with MTX. Thus, PPSV23 administration during ongoing TAC treatment should be encouraged for infection-prone TAC-treated patients with rheumatic diseases.

Trial registration

University Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0662-x) contains supplementary material, which is available to authorized users.

Economic Evaluation of Standing Order Programs for Pneumococcal Vaccination of Hospitalized Elderly Patients

Background.

Standing order programs (SOPs), which allow for vaccination without an individual physician order, are the most effective mechanism to achieve high vaccination rates. Among the suggested settings for the utilization of SOPs are hospital inpatient units, because they provide care for those most likely to benefit from vaccination. The cost-effectiveness of this approach for elderly hospitalized persons is unknown. The purpose of this study was to estimate the cost-effectiveness of SOPs for pneumococcal polysaccharide vaccine (PPV) vaccination for patients 65 years of age or older in 2 types of hospital.

Methods.

In 2004, a 1,094-bed tertiary care hospital implemented a pharmacy-based SOP for PPV, and a 225-bed community hospital implemented a nursing-based SOP for PPV. Newly admitted patients 65 years of age or older were screened for PPV eligibility and then offered PPV. Vaccination rates before and after initiation of SOPs in the United States, incidence rates of invasive pneumococcal disease in the United States, and US economic data were the bases of the cost-effectiveness analyses. One-way and multivariate sensitivity analyses were conducted.

Results.

PPV vaccination rates increased 30.5% in the tertiary care hospital and 15.3% in the community hospital. In the base-case cost-effectiveness analysis, using a societal perspective, we found that both pharmacy-based and nursing-based SOPs cost less than $10,000 per quality-adjusted life-year gained, with program costs (pharmacy-based SOPs cost $4.16 per patient screened, and nursing-based SOPs cost $4.60 per patient screened) and vaccine costs ($18.33 per dose) partially offset by potential savings from cases of invasive pneumococcal disease avoided ($12,436 per case). Sensitivity analyses showed SOPs for PPV vaccination to be cost-effective, compared with PPV vaccination without SOPs, unless the improvement in vaccination rate was less than 8%.

Conclusion.

SOPs do increase PPV vaccination rates in hospitalized elderly patients and are economically favorable, compared with PPV vaccination rates without SOPs.

Evaluation of antibody levels over 3 years after 23-valent pneumococcal polysaccharide vaccination in patients with pulmonary diseases receiving steroids and immunosuppressive agents

OBJECTIVES

Pneumococcal capsular polysaccharide vaccine is a mainstay for prevention of Streptococcus pneumoniae infection in adults. There is the possibility that this vaccine is less effective in patients undergoing immunosuppressive therapy. In the present study, we aimed to evaluate the immune response following 23-valent pneumococcal polysaccharide vaccination in pulmonary disease patients receiving steroids and immunosuppressive agents (immunosuppressive group).

DESIGN AND METHODS

Antibody levels were measured over 3 years in the immunosuppressive group (median age: 68.5 years) and in aged-match pulmonary disease patients not being treated with immunosuppressive therapy (control group) using enzyme-linked immunosorbent assays.

RESULTS

The geometric mean antibody levels were significantly increased after vaccination in both groups (p < 0.05) and remained above baseline for 3 years. The fold increases 1 month after vaccination were 9.4 (95% confidence interval [CI]: 5.7-15.6) and 8.8 (95% CI: 5.8-13.2) in the immunosuppressive and control groups, respectively (p = 0.813). There was no significant difference in the proportion of subjects with a ≥ two-fold increase of antibody level between the immunosuppressive and control groups at any point.

CONCLUSIONS

These results suggest that immunization with the 23-valent pneumococcal polysaccharide vaccine was effective, even in patients undergoing immunosuppressive therapy and should be recommended for such patients.

Characterization of the inflammatory infiltrate in Streptococcus pneumoniae pneumonia in young and elderly patients

There is an increased susceptibility and mortality in the elderly due to pneumonia caused by Streptococcus pneumoniae. We aimed to assess the inflammatory cell composition with respect to age in pneumococcal pneumonia patients. Neutrophilic granulocytes and various lymphocyte and macrophage subpopulations were immunohistochemically quantified on lung tissue specimens of young (n = 5; mean age 8.4 years), middle-aged (n = 8; mean age 55.9 years) and elderly (n = 9; mean age 86.6 years) pneumonia patients with microbiologically proven S. pneumoniae pneumonia. We discovered a higher percentage of neutrophilic granulocytes in elderly as opposed to young patients (95 vs. 75%, p = 0.012). Conversely, young patients versus elderly patients had more alveolar macrophages (CD11c+: 20 vs. 9%, p = 0.029) and M1 macrophages (CD14+: 30 vs. 10%, p = 0.012 and HLA-DR+: 52 vs. 11%, p = 0.019). There was no significant difference concerning M2 macrophages and lymphocytes. Comparison of young patients with middle-aged patients showed similar significant results for alveolar macrophages (p = 0.019) and subsignificant results for M1 macrophages and neutrophilic granulocytes (p < 0.08). This is the first study characterizing the inflammatory infiltrate of pneumococcal pneumonia in situ. Our observations improve the understanding of the innate immune mechanisms of pneumococcal lung infection and point at the potential of therapies for restoring macrophage function and decreasing neutrophilic influx in order to help prevent or cure pneumonia.

Cost-effectiveness analysis of pneumococcal conjugate vaccine 13-valent in older adults in Colombia

BACKGROUND

Nowadays, there are two vaccination strategies in Colombia to prevent pneumococcal diseases in people over 50 years. Our aim is to estimate cost-effectiveness of pneumococcal conjugate vaccine 13-valent (PCV13) versus pneumococcal polysaccharide vaccine 23-valent (PPSV23) to prevent pneumococcal diseases and their related mortality in people over 50 years old in Colombia.

METHODS

A Markov model was developed with national data, including pneumococcal serotypes distribution in Colombia between 2005 and 2010. Vaccination of a cohort was simulated and a five year time horizon was assumed. Analysis was done from a perspective of a third party payer. Direct costs were provided by a national insurance company; sensitive univariate and probabilistic analysis were done for epidemiological and clinical effectiveness parameters and costs.

RESULTS

PCV13 avoids 3 560 deaths by pneumococcal infections versus PPSV23 and 4 255 deaths versus no vaccine. PCV13 prevents 79 633 cases by all-cause pneumonia versus PPSV23 and 81 468 cases versus no vaccine. Total costs (healthcare and vaccines costs) with PCV13 would be U.S. $ 97,587,113 cheaper than PPSV23 and it would save U.S. $ 145,196,578 versus no vaccine.

CONCLUSION

PCV13 would be a cost-saving strategy in the context of a mass vaccination program in Colombia to people over 50 years old because it would reduce burden of disease and specific mortality by pneumococcal diseases, besides, it saves money versus PPSV23.

Additive preventive effect of influenza and pneumococcal vaccines in the elderly: results of a large cohort study

Elderly people are at increased risk of influenza and pneumococcal diseases. Influenza increases clinical pneumococcal disease incidence. Pneumococcal vaccination could therefore be a supplement to influenza vaccination. This study evaluated all-cause mortality and antibiotic consumption according to elderly people's influenza and pneumococcal vaccination status. Its goal was to demonstrate that vaccination with both Influenza and pneumococcal vaccines decrease all-cause mortality and antibiotic consumption. From 2004-10-01 to 2004-12-31 (3 mo), elderly people (≥ 65 y) who lived in the Gard department (South of France) were offered both vaccinations. Among the 68,897 subjects followed-up one year after this vaccination campaign, 21,303 (30.9%) were vaccinated with both vaccines, 18,651 (27.1%) with influenza vaccine alone, 3,769 (5.5%) with pneumococcal vaccine alone; 25,174 (36.5%) subjects were unvaccinated. Mortality rate (per 1,000 inhabitants-year) adjusted on gender, age and prior underlying chronic disease was 17.9 (95% CI: 16.3-19.6), 20.8 (19.0-22.8), 22.5 (19.0-26.6) and 24.7 (22.7-26.8), respectively. It was 42.1 (38.8-45.8) in elderly people with underlying chronic disease who received both vaccines vs. 58.1 (53.7-62.9) in unvaccinated elderly people. The decrease in mortality rate was 27.0% (20.0-34.0) in subjects who received both vaccines and 16.0% (6.0-24.0) in those who received influenza vaccine. No significant reduction in mortality rate was seen with the pneumococcal vaccine alone. Influenza and/or pneumococcal vaccinations did not decrease antibiotic consumption that drastically increases during the winter period. An additive effect was observed in the prevention of all-cause mortality with influenza and pneumococcal vaccines given together in elderly people, including in those with underlying chronic disease.

The immune response to pneumococcal polysaccharides 14 and 23F among elderly individuals consists predominantly of switched memory B cells

The phenotype of B cells that respond to vaccination with the purified pneumococcal polysaccharide (PPS) has been a topic of debate. We have recently identified the phenotype of cells from healthy young volunteers as CD27(+)IgM(+) B cells. However, the PPS-responding B-cell population has not yet been identified in high-risk populations, such as elderly individuals. Previous studies have shown that elderly individuals have a lower percentage of immunoglobulin M memory B cells than healthy young adults. In this study, we directly characterized the phenotype of PPS-specific B cells before and after vaccination with PPS vaccine (PPV) in elderly adults, using fluorescently labeled PPS14 and PPS23F. In contrast to our observations in healthy young volunteers, the PPS-responding B-cell population consisted primarily of switched memory (CD27(+)IgM(-)) B cells. In concurrence with these findings, postvaccination immunoglobulin M concentrations were not significantly increased in this population, and the opsonophagocytic response was decreased, compared with that in young adults. These findings identify a significant shift in the phenotype of the B-cell population in response to PPV among elderly individuals.

Vaccines for preventing pneumococcal infection in adults

BACKGROUND

Diseases caused by Streptococcus pneumoniae (S. pneumoniae) continue to cause substantial morbidity and mortality globally. Whilst pneumococcal polysaccharide vaccines (PPVs) have the potential to prevent disease and death, the degree of protection afforded against various clinical endpoints and within different populations is uncertain.

OBJECTIVES

To assess the efficacy and effectiveness of PPVs in preventing pneumococcal disease or death in adults. We did not assess adverse events.

SEARCH METHODS

We searched CENTRAL 2012, Issue 6, MEDLINE (January 1966 to June Week 2, 2012) and EMBASE (1974 to June 2012).

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) in adults, provided the study outcome met the definition of the outcome considered in the review. We also considered non-RCTs in adults, where the study assessed PPV effectiveness against culture-confirmed invasive pneumococcal disease (IPD), provided the study controlled for important confounding factors.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial quality of RCTs and three review authors extracted the data. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using a random-effects model. Two review authors assessed study quality and extracted data for non-RCTs. We calculated ORs and 95% CIs using a random-effects model following the conversion of each study outcome to a log OR and standard error (SE).

MAIN RESULTS

Twenty-five studies met our inclusion criteria (18 RCTs involving 64,852 participants and seven non-RCTs involving 62,294 participants). Meta-analysis of the RCTs found strong evidence of PPV efficacy against IPD with no statistical heterogeneity (OR 0.26, 95% CI 0.14 to 0.45; random-effects model, I(2) statistic = 0%). There was efficacy against all-cause pneumonia in low-income (OR 0.54, 95% CI 0.43 to 0.67, I(2) statistic = 19%) but not high-income countries in either the general population (OR 0.71, 95% CI 0.45 to 1.12, I(2) statistic = 93%) or in adults with chronic illness (OR 0.93, 95% CI 0.73 to 1.19, I(2) statistic = 10%). PPV was not associated with substantial reductions in all-cause mortality (OR 0.90, 95% CI 0.74 to 1.09; random-effects model, I(2) statistic = 69%). Vaccine efficacy against primary outcomes appeared poorer in adults with chronic illness. Non-RCTs provided evidence for protection against IPD in populations for whom the vaccine is currently utilised (OR 0.48, 95% CI 0.37 to 0.61; random-effects model, I(2) statistic = 31%). This review did not consider adverse events as it was outside the scope of the review.

AUTHORS' CONCLUSIONS

This meta-analysis provides evidence supporting the recommendation for PPV to prevent IPD in adults. The evidence from RCTs is less clear with respect to adults with chronic illness. This might be because of lack of effect or lack of power in the studies. The meta-analysis does not provide evidence to support the routine use of PPV to prevent all-cause pneumonia or mortality.

Pneumonia immunization in older adults: review of vaccine effectiveness and strategies

Vaccination remains the primary preventive strategy in the elderly against Streptococcus pneumoniae and influenza infections. The effectiveness of this strategy in preventing pneumonia has been in doubt despite the increase in vaccination coverage among older adults. Randomized controlled trials (RCTs) and observational studies aimed at determining clinical outcomes and immune response following pneumococcal vaccination have yielded conflicting results. The protective efficacy of pneumococcal vaccination against pneumonia in older adults has not been firmly established due to a lack of RCTs specifically examining patients ≥ 65 years of age. Similarly, the reported benefits of influenza vaccination have been derived from observational data. The assessment of clinical benefit from influenza vaccination in the elderly population is complicated by varying cohorts, virulence of the influenza strain, and matching of vaccine and circulating viral strains. The presence of selection bias and use of nonspecific end points in these studies make the current evidence inconclusive in terms of overall benefit. The development of more immunogenic vaccines through new formulations or addition of adjuvants holds the promise of revolutionizing delivery and improving efficacy. Dismantling existing barriers through education, providing technology assistance predominantly to developing countries, and establishing clear regulatory guidance on pathways for approval are necessary to ensure timely production and equitable distribution.

Public health and economic impact of 13-valent pneumococcal conjugate vaccine in US adults aged ≥50 years

BACKGROUND

A 13-valent pneumococcal conjugate vaccine (PCV13) was recently developed for use in older adults, and may be effective not only against invasive pneumococcal disease (IPD) but also nonbacteremic pneumococcal pneumonia. The potential public health and economic impact of PCV13 in this population is unknown.

METHODS

A microsimulation model depicting risk and costs of IPD and all-cause nonbacteremic pneumonia (NBP) in US adults aged ≥50 years (n=96.1 million), as well as expected impact of vaccination, was developed. Effectiveness of PPSV23 was based on published literature, and for all-cause NBP, was zero; effectiveness of PCV13 was based on PCV7 data in children, and for all-cause NBP, was varied across a reasonable range. Lifetime outcomes and costs were projected assuming: (1) use of PCV13 in all subjects at model entry, with and without periodic revaccination; and (2) use of PPSV23 per current ACIP recommendations.

RESULTS

Use of PCV13 in all subjects at model entry without revaccination - in lieu of PPSV23 use per recommendations - reduced cases of IPD by 15,000 (95% CI 9000-21,000); cases of NBP by 1.2 million (0.9-1.5); total healthcare costs by $3.5 billion (1.9-5.2); and total societal costs by $7.4 billion (5.3-9.8). Use of PCV13 with revaccination every 5-10 years resulted in fewest cases of disease and lowest total costs. Findings were largely unchanged in sensitivity analyses.

CONCLUSIONS

Assuming that the effectiveness of PCV13 in adults is comparable to that observed for PCV7 in children and under reasonable assumptions regarding the underlying risks and costs of IPD and NBP, model projections suggest that routine use of PCV13 - in lieu of PPSV23 - would result in a greater reduction in the overall burden of pneumococcal disease in older US adults.

Streptococcus pneumoniae vaccination in older adults

BACKGROUND

Streptococcus pneumoniae infections are a major cause of morbidity and mortality in older adults. Vaccination in older adults is intended to prevent S pneumoniae infections, yet little information is available regarding its efficacy in this patient population.

OBJECTIVE

The aim of this article was to review the current literature to determine the efficacy and tolerability of S pneumoniae vaccination in older adults.

METHODS

PubMed (1950-present) and EMBASE (1974-present) were searched using the search terms Streptococcus pneumoniae immunization, pneumococcus immunization, pneumococcus vaccine, and aged. Additional articles were identified from the reference lists of included studies. Studies were included if they reported information in older (55-<65 years) and elderly (≥65 years) adults and were related to at least 1 of the following topics: epidemiology of S pneumoniae, estimates of vaccine coverage, recommendations for vaccination, tolerability, and efficacy and/or effectiveness of vaccination against S pneumoniae.

RESULTS

Six randomized controlled trials and 18 observational studies that evaluated the efficacy of pneumococcal vaccination in older and elderly adults were reviewed. Findings from evaluations of efficacy, as measured by clinical outcomes and immunogenicity, in older adults have been conflicting, with some subsets of prospective, well-controlled studies finding little benefit, whereas findings from several retrospective studies have suggested significant benefit. This discord may have been a result of the limited power of the prospective subanalyses to detect significant differences.

CONCLUSIONS

In light of the potential clinical benefit and few reports of serious adverse events, vaccination in older adults is likely warranted. Prospective, well-controlled studies are needed to better quantitatively evaluate the benefit of pneumococcal vaccine in older adults.

The potential role for protein-conjugate pneumococcal vaccine in adults: what is the supporting evidence?

Vaccination with protein-conjugate pneumococcal vaccine (PCV) provides children with extraordinary protection against pneumococcal disease, although the protective effect may be blunted by the emergence of replacement strains. Studies in adults have compared PCV with pneumococcal polysaccharide vaccine (PPV) using surrogate markers of protection, namely, serum anticapsular IgG antibody and opsonic activity. Results suggest that PCV is at least as effective as PPV for the strains covered, but a definitive and consistent advantage has not been demonstrated. Unfortunately, persons who are most in need of vaccine do not respond as well as otherwise healthy adults to either vaccine. Newer formulations of PCV will protect against the most prevalent of the current replacement strains, but replacement strains will create a moving target for PCVs. Unless an ongoing trial comparing 13-valent PCV with placebo (not to PPV) demonstrates a clearly better effect than that seen in the past with PPV, cost-effectiveness considerations are likely to prevent widespread use of PCV in adults.

An appraisal of the evidence underlying performance measures for community-acquired pneumonia

Numerous organizations use performance measures to monitor the quality of care provided for a variety of clinical conditions. An appraisal of the evidence underlying such performance measures has never been reported. Our objective was to estimate the effects of interventions recommended by performance measures and to determine the quality of evidence from which those estimates derive, using the Joint Commission and the Centers for Medicare and Medicaid Services' performance measures for community-acquired pneumonia (CAP) as examples. We performed systematic reviews of the literature to identify evidence related to the performance measures for CAP. Metaanalyses were then performed to estimate the absolute and relative effects of the interventions recommended by the performance measures. The Grading Recommendations, Assessment, Development, and Evaluation system was used to determine the quality of evidence. The estimated effects favored the interventions recommended by five of the six performance measures. These included pneumococcal vaccination (incidence of pneumococcal pneumonia: relative risk [RR], 0.43; 95% confidence interval [CI], 0.24-0.75), blood cultures, antibiotic administration within 6 hours, use of a guideline-compliant antibiotic regimen, and influenza vaccination (incidence of symptomatic influenza: RR, 0.30; 95% CI, 0.22-0.40). However, among these performance measures, only influenza vaccination was supported by high-quality evidence. One-step smoking cessation counseling was contradicted by moderate-quality evidence (smoking quit rate: RR, 1.05; 95% CI, 0.90-1.22). The evidence supporting performance measures is frequently not of high quality and occasionally contradictory.

Injectable vaccines for preventing pneumococcal infection in patients with chronic obstructive pulmonary disease

BACKGROUND

As chronic obstructive pulmonary disease (COPD) progresses, exacerbations can occur with increasing frequency. One goal of therapy is to prevent these exacerbations, thereby reducing morbidity and associated healthcare costs. Pneumococcal vaccinations are one strategy for reducing the risk of infective exacerbations.

OBJECTIVES

To determine the safety and efficacy of pneumococcal vaccination in COPD. The primary outcomes assessed were episodes of pneumonia and acute exacerbations. Secondary outcomes of interest included hospital admissions, adverse events related to treatment, disability, change in lung function, mortality, and cost effectiveness.

SEARCH STRATEGY

We searched the Cochrane Airways Group COPD trials register and the databases CENTRAL, MEDLINE and EMBASE using pre-specified terms. The latest searches were performed in March 2010.

SELECTION CRITERIA

Randomised controlled trials assessing the effects of injectable pneumococcal vaccine in people with COPD were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and three review authors independently assessed trial quality.

MAIN RESULTS

Seven studies were identified that met the inclusion criteria for this review and were included in the 2010 review update. Two older trials used a 14-valent vaccine and five more recent trials used a 23-valent injectable vaccine.In six studies involving 1372 people, the reduction in likelihood of developing pneumonia with pneumococcal vaccination compared to control did not achieve statistical significance, the odds ratio (OR) was 0.72 (95% confidence interval (CI) 0.51 to 1.01), with moderate heterogeneity present between studies. The reduction in likelihood of acute exacerbations of COPD from two studies involving 216 people was not statistically significant (Peto OR 0.58; 95% CI 0.30 to 1.13).Of the secondary outcomes for which data were available there was no statistically significant effect for reduction in hospital admissions (two studies) or emergency department visits (one study). There was no significant reduction in pooled results from three studies involving 888 people for odds of all-cause mortality for periods up to 48 months post-vaccination (OR 0.94; 95% CI 0.67 to 1.33), or for death from cardiorespiratory causes (OR 1.07; 95% CI 0.69 to 1.66).

AUTHORS' CONCLUSIONS

The limited evidence from randomised controlled trials (RCTs) included in this review suggests that, while it is possible that injectable polyvalent pneumococcal vaccines may provide some protection against morbidity in persons with COPD, no significant effect on any of the outcomes was shown. Further large RCTs in this population would be needed to confirm effectiveness of the vaccine suggested by results from longitudinal studies.