The effectiveness of pneumococcal polysaccharide vaccine 23 (PPV23) in the general population of 50 years of age and older: A systematic review and meta-analysis

A Systematic Review of Studies Published between 2016 and 2019 on the Effectiveness and Efficacy of Pneumococcal Vaccination on Pneumonia and Invasive Pneumococcal Disease in an Elderly Population

Adult vaccination is high on the agenda in many countries. Two different vaccines are available for the prevention of pneumococcal disease in adults: a 23-valent polysaccharide vaccine (PPV23), and a 13-valent conjugated vaccine (PCV13). The objective of this review is to update the evidence base for vaccine efficacy and effectiveness of PPV23 and PCV13 against invasive pneumococcal disease and pneumonia among an unselected elderly population. We systematically searched for clinical trials and observational studies published between January 1 2016 and April 17 2019 in Pubmed, Embase, Cinahl, Web of Science, Epistemonikos and Cochrane databases. Risk of bias was assessed using Cochrane Risk of Bias tool for and the Newcastle–Ottawa Scale. Results were stratified by vaccine type and outcome. We identified nine studies on PCV13 and six on PPV23. No new randomized clinical trials were identified. Due to different outcomes, it was not possible to do a meta-analysis. New high-quality observational studies indicate protective vaccine effectiveness for both vaccines against vaccine type pneumonia. Our estimates for the protective vaccine efficacy and effectiveness (VE) of PPV23 on pneumonia and pneumococcal pneumonia overlap with results from previously published reviews. Some of the results indicate that the effectiveness of the PPV23 is best in younger age groups, and that it decreases over time.

Development of Next Generation Streptococcus pneumoniae Vaccines Conferring Broad Protection

Streptococcus pneumoniae is a major pathogen causing pneumonia with over 2 million deaths annually, especially in young children and the elderly. To date, at least 98 different pneumococcal capsular serotypes have been identified. Currently, the vaccines for prevention of S. pneumoniae infections are the 23-valent pneumococcal polysaccharide-based vaccine (PPV23) and the pneumococcal conjugate vaccines (PCV10 and PCV13). These vaccines only cover some pneumococcal serotypes and are unable to protect against non-vaccine serotypes and unencapsulated S. pneumoniae. This has led to a rapid increase in antibiotic-resistant non-vaccine serotypes. Hence, there is an urgent need to develop new, effective, and affordable pneumococcal vaccines, which could cover a wide range of serotypes. This review discusses the new approaches to develop effective vaccines with broad serotype coverage as well as recent development of promising pneumococcal vaccines in clinical trials. New vaccine candidates are the inactivated whole-cell vaccine strain (Δpep27ΔcomD mutant) constructed by mutations of specific genes and several protein-based S. pneumoniae vaccines using conserved pneumococcal antigens, such as lipoprotein and surface-exposed protein (PspA). Among the vaccines in Phase 3 clinical trials are the pneumococcal conjugate vaccines, PCV-15 (V114) and 20vPnC. The inactivated whole-cell and several protein-based vaccines are either in Phase 1 or 2 trials. Furthermore, the recent progress of nanoparticles that play important roles as delivery systems and adjuvants to improve the performance, as well as the immunogenicity of the nanovaccines, are reviewed.

Community-Acquired Pneumonia. Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) Guidelines. 2020 Update

The guidelines for community-acquired pneumonia, last published in 2010, have been updated to provide recommendations based on a critical summary of the latest literature to help health professionals make the best decisions in the care of immunocompetent adult patients. The methodology was based on 6 PICO questions (on etiological studies, assessment of severity and decision to hospitalize, antibiotic treatment and duration, and pneumococcal conjugate vaccination), agreed by consensus among a working group of pulmonologists and an expert in documentation science and methodology. A comprehensive review of the literature was performed for each PICO question, and these were evaluated in in-person meetings. The American Thoracic Society guidelines were published during the preparation of this paper, so the recommendations of this association were also evaluated. We concluded that the etiological source of the infection should be investigated in hospitalized patients who have suspected resistance or who fail to respond to treatment. Prognostic scales, such as PSI, CURB 65, and CRB65, are useful for assessing severity and the decision to hospitalize. Different antibiotic regimens are indicated, depending on the treatment setting - outpatient, hospital, or intensive care unit - and the resistance of PES microorganisms should be calculated. The minimum duration of antibiotic treatment should be 5 days, based on criteria of clinical stability. Finally, we reviewed the indication of the 13-valent conjugate vaccine in immunocompetent patients with risk factors and comorbidity.

Indirect costs of adult pneumococcal disease and the productivity-based rate of return to the 13-valent pneumococcal conjugate vaccine for adults in Turkey

Productivity benefits of health technologies are ignored in typical economic evaluations from a health payer’s perspective, risking undervaluation. We conduct a productivity-based cost-benefit analysis from a societal perspective and estimate indirect costs of adult pneumococcal disease, vaccination benefits from the adult 13-valent pneumococcal conjugate vaccine (PCV13 Adult), and rates of return to PCV13 Adult for a range of hypothetical vaccination costs. Our context is Turkey’s funding PCV13 for the elderly and for non-elderly adults with select comorbidities within the Ministry of Health’s National Immunization Program. We use a Markov model with one-year cycles. Indirect costs from death or disability equal the expected present discounted value of lifetime losses in the infected individual’s paid and unpaid work and in caregivers’ paid work. Vaccination benefits comprise averted indirect costs. Rates of return equal vaccination benefits divided by vaccination costs, minus one. Input parameters are from public data sources. We model comorbidities’ effects by scalar multiplication of the parameters of the general population. Indirect costs per treatment episode of inpatient community-acquired pneumonia (CAP), bacteremia, and meningitis – but not for outpatient CAP – approach or exceed Turkish per capita gross domestic product. Vaccination benefits equal $207.02 per vaccination in 2017 US dollars. The rate of return is positive for all hypothetical costs below this. Results are sensitive to herd effects from pediatric vaccination and vaccine efficacy rates. For a wide range of hypothetical vaccination costs, the rate of return compares favorably with those of other global development interventions with well-established strong investment cases.

Immunosenescence and human vaccine immune responses

The age-related dysregulation and decline of the immune system-collectively termed "immunosenescence"-has been generally associated with an increased susceptibility to infectious pathogens and poor vaccine responses in older adults. While numerous studies have reported on the clinical outcomes of infected or vaccinated individuals, our understanding of the mechanisms governing the onset of immunosenescence and its effects on adaptive immunity remains incomplete. Age-dependent differences in T and B lymphocyte populations and functions have been well-defined, yet studies that demonstrate direct associations between immune cell function and clinical outcomes in older individuals are lacking. Despite these knowledge gaps, research has progressed in the development of vaccine and adjuvant formulations tailored for older adults in order to boost protective immunity and overcome immunosenescence. In this review, we will discuss the development of vaccines for older adults in light of our current understanding-or lack thereof-of the aging immune system. We highlight the functional changes that are known to occur in the adaptive immune system with age, followed by a discussion of current, clinically relevant pathogens that disproportionately affect older adults and are the central focus of vaccine research efforts for the aging population. We conclude with an outlook on personalized vaccine development for older adults and areas in need of further study in order to improve our fundamental understanding of adaptive immunosenescence.

Cost Effectiveness of Elderly Pneumococcal Vaccination in Presence of Higher-Valent Pneumococcal Conjugate Childhood Vaccination: Systematic Literature Review with Focus on Methods and Assumptions

BACKGROUND

Previous systematic reviews concluded that pneumococcal vaccination in the elderly was cost effective. However, recently published economic evaluations state that it may not be cost effective when children are vaccinated with higher-valent pneumococcal conjugate vaccines. The literature suggests that the outcomes of vaccination in the elderly are strongly influenced by the vaccine effectiveness (VE) against the vaccine-type pneumococcal diseases (PD) and the impact of childhood vaccination on the vaccine-type PD incidence in the elderly, but the extent remains unclear.

METHODS

We conducted a systematic literature search of cost-effectiveness studies on vaccination in the elderly in the PubMed database starting from 2006. We included studies that consider the presence of a childhood vaccination with pneumococcal conjugate vaccine (PCV) 10 and PCV13. We focus on methods and assumptions used in modeling VE and epidemiology of PD over time.

RESULTS

Twenty-eight economic evaluations underwent full-text review and data extraction. Thirteen were selected for quality assessment. The studies with a higher quality score provide evidence that vaccinating the elderly with PCV13 is not cost effective, when an ongoing rapid decline in the incidence of PCV13-type PD is modeled. A moderate persistence of PCV13 serotypes, in particular due to PCV10 childhood vaccination, makes vaccination of the elderly with PCV13 more attractive. There is no agreement that combining PCV13 with polysaccharide vaccine PPSV23 is cost effective. PPSV23 is attractive when it is effective against non-invasive PD.

CONCLUSION

Methodological approaches and assumptions in modeling VE and the indirect effects of childhood vaccination have a major impact on outcomes of decision-analytic models and cost-effectiveness estimates. Considering recently observed trends in the epidemiology of pneumococcal serotypes, there is currently inconclusive evidence regarding the cost effectiveness of pneumococcal vaccination of the elderly due to lack of studies that model key serotypes such as serotype 3 separately from other groups of serotypes.

Streptococcus pneumoniae serotype 3 is masking PCV13-mediated herd immunity in Canadian adults hospitalized with community acquired pneumonia: A study from the Serious Outcomes Surveillance (SOS) Network of the Canadian immunization research Network (CIRN)

BACKGROUND

The 13-valent pneumococcal conjugate vaccine (PCV13) was recently shown to be effective against PCV13-type invasive pneumococcal disease (IPD) and pneumococcal community acquired pneumonia (CAP_Spn) in healthy adults aged ≥65 years, prompting many countries to re-assess adult immunization. In Canada, the potential benefits of adult PCV13 immunization were unclear given anticipated herd immunity from PCV13 childhood immunization introduced since 2010. This study describes the serotype distribution and clinical outcomes of Canadian adults aged ≥16 years, who were hospitalized with CAP_Spn and IPD from 2010 to 2015.

METHODS

Active surveillance for CAP and IPD was performed in adult hospitals across five Canadian provinces. IPD was identified when Streptococcus pneumoniae was isolated from sterile sites. Bacteremic and non-bacteremic CAP_Spn were identified using blood culture, and sputum culture or PCV13-specific urine antigen detection (UAD_PCV13), respectively. Serotype was assigned using Quellung reaction, PCR, or UAD_PCV13.

RESULTS

Of 6687 CAP cases where a test was performed, S. pneumoniae positivity decreased from 15.9% in 2011 to 8.8% in 2014, but increased to 12.9% in 2015. CAP_Spn attributed to PCV13 serotypes followed a similar trend, dropping from 8.3% in 2010 to 4.6% in 2014, but increasing to 6.3% in 2015. The decline was primarily attributed to serotypes 7F and 19A, and the proportional increase to serotype 3. Similar trends were noted for bacteremic and non-bacteremic CAP_Spn. Serious outcomes such as 30-day mortality, intensive care unit admission, and requirement for mechanical ventilation were prominent in CAP_Spn and IPD cases, but remained unchanged over the study years.

CONCLUSION

Herd immunity afforded primarily by serotypes 7F and 19A appears to be partly masked by a concomitant proportional increase of serotype 3. Despite evidence of herd immunity, these PCV13 serotypes remain persistent in Canadian adults hospitalized with CAP_Spn, and represent between 5 and 10% of all CAP in this patient population.

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.

Direct effectiveness of pneumococcal polysaccharide vaccine against invasive pneumococcal disease and non-bacteremic pneumococcal pneumonia in elderly population in the era of pneumococcal conjugate vaccine: A case-control study

BACKGROUND

While herd effects and serotype replacement by childhood pneumococcal protein conjugated vaccines (PCVs) continues to accumulate worldwide, direct effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPV23) against pneumococcal diseases in the elderly has been challenged. We estimated the direct effectiveness of PPV23 in the elderly population.

METHODS

For a hospital-based case-control study, cases of invasive pneumococcal disease (IPD) and non-bacteremic pneumococcal pneumonia (NBPP) (adults ≥ 65 years) were identified in 14 hospitals participated in the pneumococcal surveillance program from March 2013 to October 2015, following implementation of PPV23 national immunization program (NIP) for the elderly in the Republic of Korea. Controls matched by age, sex, and hospital were selected at ratios of 1:2 (IPD) or 1:1 (NBPP). Clinical data and vaccination records were collected. Vaccine effectiveness was calculated as (1-adjusted odds ratio) × 100.

RESULTS

We enrolled 148 IPD and 557 NBPP cases, and 295 IPD and 557 NBPP controls for analyses. Overall effectiveness of PPV23 against IPD was 28.5% [95% confidence interval (CI) -5.8%-51.6%] and against NBPP was 10.2% (-15.1-30.6) in all patients ≥ 65 years. However, in subgroup analysis of patients aged 65-74 years, PPV23 was protective against IPD [effectiveness 57.4% (19.4-77.5)] and against NBPP [effectiveness 35.0% (2.3-56.7)]. Furthermore, serotype-specific effectiveness of PPV23 against IPD was 90.6% (27.6-98.8) for PPV23-unique serotypes and 81.3% (38.6-94.3) for PPV23 serotypes excluding serotype 3.

CONCLUSIONS

This study indicates that PPV23 with broad serotype coverage might be beneficial in preventing IPD and NBPP due to non-PCV13 serotypes in the young-elderly, with potentially increasing effectiveness in the setting of childhood PCV NIP.

Impact of pneumococcal conjugate vaccines on hospitalizations for pneumonia in the United States

INTRODUCTION

Pneumonia is one of the leading causes of morbidity and mortality among children and older adults. Pneumococcal conjugate vaccines (PCVs) were introduced into the US routine infant vaccination schedule leading to substantial reductions of invasive pneumococcal diseases (IPD). PCV introduction also led to reductions in all-cause pneumonia among US children, though the indirect impact of PCVs on pneumonia in adults is difficult to quantify, especially due to the recent US recommendation for direct PCV use in older adults. Areas covered: We described the existing evidence for both the direct and indirect impact of PCVs on pneumonia among children and adults in the US since PCV introduction. Expert commentary: The introduction of PCVs into the US routine infant vaccination schedule led to important reductions in the burden of IPD and non-invasive pneumonia among vaccinated and unvaccinated populations. The impact of direct vaccination of older adults in the US since 2014, though difficult to quantify, is currently being evaluated. As pneumonia remains one of the leading causes of morbidity and mortality in the US, future evaluations of the direct and indirect effects of current and expanded valency PCVs in the US population are needed.

Epidemiological and clinical features of invasive pneumococcal disease caused by serotype 12F in adults, Japan

Enhanced surveillance of invasive pneumococcal disease (IPD) in adults was conducted during April 2013–March 2018 in 10 of 47 prefectures in Japan, and a total of 1277 IPD patients were enrolled. An emergence of IPD caused by serotype 12F was identified during May 2015–March 2018 through this surveillance. 12F isolates were composed of four related sequence types. In total, 120 patients with 12F IPD were reported during this period. To characterize the clinical features of 12F IPD, the disease characteristics of these patients were compared with those of 1157 patients with non-12F IPD. Compared with the non-12F IPD patients, a significantly lower proportion of 12F IPD patients was aged 65 years or older (55% vs. 70%), vaccinated with 23-valent pneumococcal polysaccharide (4% vs. 14%), had comorbid illness (65% vs. 77%), or were immunocompromised (19% vs. 30%; all P < 0.05). No significant difference in the proportion of case fatalities was found between the two groups. The proportions of those aged 65 years or older (53% vs. 69%) and with bacteremic pneumonia (35% vs. 69%) were significantly lower in 17 patients who died from 12F IPD than in 205 patients who died from non-12F IPD (all P < 0.05). Differences in clinical features were similarly found between 12F IPD patients and patients in low- or intermediate-level invasive potential serogroups. Our data demonstrated that serotype 12F was associated with IPD in younger adults and a lower proportion of comorbid illness, including immunocompromised conditions, in adult IPD, suggesting the high invasive potential of the serotype 12F. In addition, patients who died from 12F IPD were younger and had proportionately more bacteremia without focus. These findings may provide new insight into the pathogenesis of IPD in adults caused by 12F serotype with a high invasive potential.

Adult vaccination for pneumococcal disease: a comparison of the national guidelines in Europe

Pneumococcal disease constitutes a major global health problem. Adults aged over 50 years and younger adults with specific chronic health conditions are at risk for invasive pneumococcal disease, associated with substantial morbidity and mortality. In Europe, two vaccine types are used in adults for pneumococcal immunization: pneumococcal polysaccharide vaccine (PPV23) and pneumococcal conjugate vaccine (PCV13). To provide an overview and to compare the national guidelines for pneumococcal immunization for adults in Europe. In November 2016, national guidelines on pneumococcal vaccination for adults of 31 European countries were obtained by Google search, the website of European Centre for Disease Prevention and Control, and contacting public health officials. In our analysis, we distinguished between age-based and risk-based guidelines. In October 2017, we used the same method to retrieve guideline updates. We observed great variability regarding age, risk groups, vaccine type, and use of boosters. In age-based guidelines, vaccination is mostly recommended in adults aged over 65 years using PPV23. Boosters are generally not recommended. An upper age limit for vaccination is reported in three countries. In the immunocompromised population, vaccination with both vaccines and administration of a booster is mostly recommended. In the population with chronic health conditions, there is more heterogeneity according vaccine type, sequence, and administration of boosters. Asplenia is the only comorbidity for which all countries recommend vaccination. The great variability in European pneumococcal vaccination guidelines warrants European unification of the guidelines for better control of pneumococcal disease.

Impact of Postoperative Pneumonia Developing After Discharge on Long-Term Follow-up for Resected Lung Cancer

BACKGROUND

Postoperative nosocomial pneumonia is a common immediate complication following lung resection. However, the incidence and mortality of pneumonia developing after discharge (PDAD) for lung-resected patients during long-term observation remain unclear. The aim of this study was to investigate the clinical features of PDAD in patients with resected lung cancer.

METHODS

We conducted a retrospective cohort study of 357 consecutive patients with lung cancer who had undergone lung resection at a single institution, between April 2007 and December 2016. The clinical characteristics, pathological features, and overall survival were analyzed. Propensity score matched analysis was used for the evaluation of overall survival between PDAD and non-PDAD groups with adjusted relevant confounding factors.

RESULTS

PDAD was observed in 66 patients (18.5%). The cumulative incidence of PDAD was 14.9% at 3 years and 21.6% at 5 years. Mortality of PDAD was 30.3%. Multivariate analysis demonstrated that the risk factors for PDAD were age (OR 1.07; P = 0.005), oral steroid use (OR 5.62; P = 0.046), and lower-lobe resection (OR 1.87; P = 0.034). After propensity score matching, 52 patients with PDAD and 52 patients without it were compared. The incidence of PDAD resulted in a worse 5-year overall survival (56.1 vs. 69.3%; P = 0.024). The Cox proportional hazards model indicated that PDAD was associated with poor overall survival (HR 1.99, P = 0.027).

CONCLUSIONS

Our findings revealed a high incidence and mortality of PDAD among patients who had undergone lung resection with long-term follow-up. Therefore, PDAD could be associated with poorer overall survival.

Cost-effectiveness of alternative strategies for use of 13-valent pneumococcal conjugate vaccine (PCV13) in Canadian adults

OBJECTIVES

The Canadian National Advisory Committee on Immunization (NACI) recommends use of 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine in a sequential schedule (PCV13 → PPV23) among adults aged ≥ 65 years and those aged ≥ 18 years who are immunocompromised. In light of recent PCV13 efficacy data from the Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA), and new sero-epidemiology data on community-acquired pneumonia (CAP), we examined the economic implications of funding an expanded adult pneumococcal immunization program in Canada.

METHODS

A microsimulation model depicting expected lifetime risks, consequences, and costs of invasive pneumococcal disease (IPD) and CAP was developed. PPV23 effectiveness was based on published literature, and PCV13 effectiveness was based on CAPiTA; all other model parameters were based on published data or secondary sources. Herd effects from the PCV13 pediatric program were considered. Outcomes and costs were evaluated assuming use of PPV23 alone, and alternatively, use of PCV13 → PPV23 among (1) all adults aged ≥ 65 years (n = 5.4 M) and (2) immunocompromised and high-risk adults aged ≥ 65 years (n = 3.0 M).

RESULTS

For population no. 1, PCV13 → PPV23 reduced IPD cases by 1100, CAP cases by 7000, and disease costs by $135.8M; vaccination costs increased by $254.3M, and cost per QALY gained was $35,484. For population no. 2, PCV13 → PPV23 reduced IPD cases by 900, CAP cases by 6000, and disease costs by $120.3M; vaccination costs increased by $149.8M, and cost per QALY gained was $10,728.

CONCLUSION

Expanding use of PCV13 → PPV23 by funding PCV13 among Canadian adults aged ≥ 65 would be a cost-effective use of healthcare resources.

Factors associated with pneumococcal vaccination in elderly people: a cross-sectional study among elderly club members in Miyakonojo City, Japan

BACKGROUND

Pneumonia is the third leading cause of death in Japan. All elderly people aged 65 years or older are recommended to receive a pneumococcal vaccine. A subsidy for part of the cost of routine pneumococcal vaccination in this age group was introduced in 2014. Factors related to vaccination behavior among elderly adults have not been well reported. The purpose of this study was to investigate factors associated with vaccine uptake among elderly people in Japan.

METHODS

We conducted a cross-sectional study, using a self-administered questionnaire among elderly club members aged 65 years or older in one city of Japan in April 2017. The participants were selected from among all elderly club members in the study area. Variables extracted from the questionnaire were analyzed using logistic regression analysis.

RESULTS

A total of 208 elderly club members participated in the study. The mean age (± SD) was 77.2 (± 5.3) years. The pneumococcal vaccination rate was 53.2%. Logistic regression analysis revealed three variables that had a significant association with pneumococcal vaccination: a recommendation for vaccination from medical personnel (aOR 8.42, 95% CI 3.59-19.72, p <  0.001), receiving influenza vaccination in any of the previous three seasons (aOR 3.94, 95% CI 1.70-9.13, p = 0.001), and perception of the severity of pneumonia (aOR 1.23, 95% CI 1.03-1.48, p = 0.026).

CONCLUSIONS

Although the pneumococcal vaccination rate in this study was increased compared with previous reports, almost half of study participants had not yet received vaccination. Our findings could be helpful for developing vaccination strategies to increase the vaccine coverage in the elderly population.

Retrospective cost-effectiveness of the 23-valent pneumococcal polysaccharide vaccination program in Australia

BACKGROUND

The Australian infant pneumococcal vaccination program was funded in 2005 using the 7-valent pneumococcal conjugate vaccine (PCV7) and the 13-valent conjugate vaccine (PCV13) in 2011. The PCV7 and PCV13 programs resulted in herd immunity effects across all age-groups, including older adults. Coincident with the introduction of the PCV7 program in 2005, 23-valent pneumococcal polysaccharide vaccine (PPV23) was funded for all Australian adults aged over 65 years.

METHODS

A multi-cohort Markov model with a cycle length of one year was developed to retrospectively evaluate the cost-effectiveness of the PPV23 immunisation program from 2005 to 2015. The analysis was performed from the healthcare system perspective with costs and quality-adjusted life years discounted at 5% annually. The incremental cost-effectiveness ratio (ICER) for PPV23 doses provided from 2005 to 2015 was calculated separately for each year when compared to no vaccination. Parameter uncertainty was explored using deterministic and probabilistic sensitivity analysis.

RESULTS

It was estimated that PPV23 doses given out over the 11-year period from 2005 to 2015 prevented 771 hospitalisations and 99 deaths from invasive pneumococcal disease (IPD). However, the estimated IPD cases and deaths prevented by PPV23 declined by more than 50% over this period (e.g. from 12.9 deaths for doses given out in 2005 to 6.1 in 2015), likely driven by herd effects from infant PCV programs. The estimated ICER over the period 2005 to 2015 was approximately A$224,000/QALY gained compared to no vaccination. When examined per year, the ICER for each individual year worsened from $140,000/QALY in 2005 to $238,000/QALY in 2011 to $286,000/QALY in 2015.

CONCLUSION

The cost-effectiveness of the PPV23 program in older Australians was estimated to have worsened over time. It is unlikely to have been cost-effective, unless PPV23 provided protection against non-invasive pneumococcal pneumonia and/or a low vaccine price was negotiated. A key policy priority should be to review of the future use of PPV23 in Australia, which is likely to be more cost-effective in certain high-risk groups.

Pneumococcal Disease and the Effectiveness of the PPV23 Vaccine in Adults: A Two-Stage Bayesian Meta-Analysis of Observational and RCT Reports

The efficacy of PPV-23 vaccine on outcomes of pneumococcal disease in adults still remains controversial due mainly to the lack of consistency between the results obtained from observational studies(OSs) and those obtained from randomized controlled trials(RCTs). As a consequence, the complexity in the structure of evidence available, in turn, generates a challenge for combining disparate pieces of evidence quantitatively. In this regard, we used a hierarchical Bayesian inference-based evidence synthesis of RCTs and observational data using a two-stage approach (in addition to a traditional random-effects meta-analysis) to examine the effectiveness of PPV-23 in adults. To this end, 21 studies were included involving 826109 adult participants. By a two-stage Bayesian meta-analysis, which was directly used for combining studies of different designs, the overall log OR (95% credible interval) for IPDs was -0.1048 (-0.3920,-0.0250), indicating a significant protective effect of the vaccination against IPDs. No significant effect of PPV-23 was found on all-cause pneumonia, pneumococcal pneumonia, and death from pneumonia, which confirmed the results obtained by a traditional method followed by stratified and sensitivity analyses. The estimated overall log OR (95% credible interval) was -0.0002 (-0.0241,0.0142), -0.0002 (-0.0110,0.0122), and -6.3912 × 10-5 (-0.0219,0.0131), respectively. The PPV-23 vaccine might be effective in preventing the most severe invasive forms of pneumococcal diseases, but not effective in preventing other clinical outcomes, in the adult population of 18 years and older.

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.

Economic evaluation of pneumococcal vaccines for adults aged over 50 years in Belgium

Streptococcus pneumoniae causes a high disease burden including pneumonia, meningitis and septicemia. Both a polysaccharide vaccine targeting 23 serotypes (PPV23) and a 13-valent conjugate vaccine (PCV13) are indicated for persons aged over 50 years. We developed and parameterized a static multi-cohort model to estimate the incremental cost-effectiveness and budget-impact of these vaccines at different uptake levels. Using three different vaccine efficacy scenarios regarding non-invasive pneumococcal pneumonia and extensive uni- and multivariate sensitivity analyses, we found a strong preference for PPV23 over PCV13 in all age groups at willingness to pay levels below €300 000 per quality adjusted life year (QALY). PPV23 vaccination would cost on average about €83 000, €60 000 and €52 000 per QALY gained in 50-64, 65-74 and 75-84 year olds, whereas for PCV13 this is about €171 000, €201 000 and €338 000, respectively. Strategies combining PPV23 and PCV13 vaccines were most effective but generally less cost-effective. When assuming a combination of increased duration of PCV13 protection, increased disease burden preventable by PCV13 and a 75% reduction of the PCV13 price, PCV13 could become more attractive in <75 year olds, but would remain less attractive than PPV23 from age 75 years onwards. These observations are independent of the assumption that PPV23 has 0% efficacy against non-invasive pneumococcal pneumonia. Pneumococcal vaccination would be most cost-effective in Belgium, when achieving high uptake with PPV23 in 75-84 year olds, as well as by negotiating a lower market-conform PPV23 price to improve uptake and cost-effectiveness.

Accuracy of High-Throughput Nanofluidic PCR-Based Pneumococcal Serotyping and Quantification Assays Using Sputum Samples for Diagnosing Vaccine Serotype Pneumococcal Pneumonia: Analyses by Composite Diagnostic Standards and Bayesian Latent Class Models

The lack of reliable diagnostic tests for detecting vaccine serotype pneumococcal pneumonia (VTPP) remains a challenging issue in pneumococcal vaccine studies. This study assessed the performances of high-throughput nanofluidic PCR-based pneumococcal serotyping and quantification assay methods using sputum samples (the nanofluidic sputum quantitative PCR [Sp-qPCR] assay) to diagnose 13-valent pneumococcal conjugate VTPP compared with the performance of the serotype-specific urinary antigen detection (UAD) assay using urine samples. Adult pneumonia patients from Japan were enrolled in this study between September 2012 and August 2014. Sputum samples were subjected to the nanofluidic Sp-qPCR assay, quantitatively cultured, and serotyped by the Quellung reaction (SpQt). Urine samples were tested by the UAD method. The diagnostic performances of these tests were assessed using composite reference standards and Bayesian latent class models (BLCMs). Among 244 total patients, 27 (11.1%) tested positive with the UAD assay, while 16 (6.6%) and 34 (13.9%) tested positive with the SpQt and nanofluidic Sp-qPCR assays, respectively, with a cutoff value of ≥10⁴ DNA copies/ml, which showed the maximum value of the Youden index. Using BLCMs, the estimated prevalence for VTPP was 12.9%, and the nanofluidic Sp-qPCR assay demonstrated the best performance (sensitivity, 90.2%; specificity, 96.9%), followed by UAD (sensitivity, 75.6%; specificity, 97.9%) and SpQt (sensitivity, 45.8%; specificity, 99.5%). However, when a higher cutoff value of ≥10⁷ DNA copies/ml was applied, the performance of UAD became comparable to that of Sp-qPCR. The vaccine serotype-specific pneumococcal DNA load in sputum among UAD-positive patients was 3 logs higher than that among UAD-negative patients (P = 0.036). The nanofluidic Sp-qPCR assay may be accurate and useful for detecting VTPP among adults.

Report on WHO meeting on immunization in older adults: Geneva, Switzerland, 22-23 March 2017

Many industrialized countries have implemented routine immunization policies for older adults, but similar strategies have not been widely implemented in low- and middle-income countries (LMICs). In March 2017, the World Health Organization (WHO) convened a meeting to identify policies and activities to promote access to vaccination of older adults, specifically in LMICs. Participants included academic and industry researchers, funders, civil society organizations, implementers of global health interventions, and stakeholders from developing countries with adult immunization needs. These experts reviewed vaccine performance in older adults, the anticipated impact of adult vaccination programs, and the challenges and opportunities of building or strengthening an adult and older adult immunization platforms. Key conclusions of the meeting were that there is a need for discussion of new opportunities for vaccination of all adults as well as for vaccination of older adults, as reflected in the recent shift by WHO to a life-course approach to immunization; that immunization in adults should be viewed in the context of a much broader model based on an individual's abilities rather than chronological age; and that immunization beyond infancy is a global priority that can be successfully integrated with other interventions to promote healthy ageing. As WHO is looking ahead to a global Decade of Healthy Ageing starting in 2020, it will seek to define a roadmap for interdisciplinary collaborations to integrate immunization with improving access to preventive and other healthcare interventions for adults worldwide.

Pneumococcal vaccination in older persons: where are we today?

Disease due to Streptococcus pneumoniae, the pneumococcus, remains a major source of illness in older persons. Globally, it remains the most important pathogen in respiratory infection deaths.

Conjugated pneumococcal vaccines are used extensively in national pediatric programs, whereas a polysaccharide vaccine is used in all age groups, but mainly in the elderly and for high-risk groups.

Recent data from the Netherlands led to the licensing in many countries of conjugated pneumococcal vaccines for older persons. There are substantial differences in recommendations from various national immunization technical advisory groups, which owe at least as much to differing assessments of available studies as to differences in local epidemiology.

This review examines those differences and proposes a way forward.

Pneumococcal vaccination and chronic respiratory diseases

Patients with COPD and other chronic respiratory diseases are especially vulnerable to viral and bacterial pulmonary infections, which are major causes of exacerbations, hospitalization, disease progression, and mortality in COPD patients. Effective vaccines could reduce the burden of respiratory infections and acute exacerbations in COPD patients, but what is the evidence for this? This article reviews and discusses the existing evidence for pneumococcal vaccination efficacy and its changing role in patients with chronic respiratory diseases, especially COPD. Specifically, the recent Community-Acquired Pneumonia Immunization Trial in Adults (CAPITA) showed the efficacy of pneumococcal conjugate vaccine in older adults, many of whom had additional risk factors for pneumococcal disease, including chronic lung diseases. Taken together, the evidence suggests that pneumococcal and influenza vaccinations can prevent community-acquired pneumonia and acute exacerbations in COPD patients, while pneumococcal vaccination early in the course of COPD could help maintain stable health status. Despite the need to prevent pulmonary infections in patients with chronic respiratory diseases and evidence for the efficacy of pneumococcal conjugate vaccine, pneumococcal vaccine coverage and awareness are low and need to be improved. Respiratory physicians need to communicate the benefits of vaccination more effectively to their patients who suffer from chronic respiratory diseases.

Determining best outcomes from community-acquired pneumonia and how to achieve them

Community-acquired pneumonia (CAP) is a common acute medical illness with a standard, effective treatment that was introduced before the evidenced-based medicine era. Mortality rates have improved in recent decades but improvements have been minimal when compared to other conditions such as acute coronary syndromes. The standardized approach to treatment makes CAP a target for comparative performance and outcome measures. While easy to collect, simplistic outcomes such as mortality, readmission and length of stay are difficult to interpret as they can be affected by subjective choices and health care resources. Proposed clinical- and patient-reported outcomes are discussed below and include measures such as the time to clinical stability (TTCS) and patient satisfaction, which can be compared between health institutions. Strategies to improve these outcomes include use of a risk stratification tool, local antimicrobial guidelines with antibiotic stewardship and care bundles to include early administration of antibiotics and early mobilization.

Implementing a Multidisciplinary Approach to Enhance Compliance With Guideline-Recommended Prechemotherapy Pneumococcal Vaccination in a Military-Based Medical Oncology Practice

Purpose:

Patients with cancer are at increased risk for invasive pneumococcal disease, including community-acquired pneumonia. Current Advisory Committee on Immunization Practices and National Cancer Comprehensive Network guidelines recommend pneumococcal vaccination for immunocompromised patients, including patients with cancer.

Methods:

We conducted a quality improvement (QI) project to enhance compliance with pneumococcal vaccination in patients before their chemotherapy. Baseline pneumococcal vaccination rates were gathered from July 2013 to June 2014. We reviewed the current guidelines for pneumococcal vaccinations in patients with cancer with physicians and encouraged them to prescribe the pneumococcal vaccination to patients before therapy. We also recruited our clinic nurse practitioner, who meets all patients for chemotherapy teaching, to prescribe the vaccine to patients younger than 65 years of age.

Results:

During the baseline period, of the 110 patients younger than 65 years who received chemotherapy, seven (6.4%) received the pneumococcal vaccine. Of the 90 patients (median age, 60 years; range, 20 to 86 years) who received chemotherapy during the study period, 58 were younger than 65 years, of whom three patients were already vaccinated before their diagnosis. Twenty-five (45.5%) patients were vaccinated through our QI project. We have improved our compliance with pneumococcal vaccination by 39% ( P < .001).

Conclusion:

We have improved compliance with pneumococcal vaccination in patients with cancer receiving chemotherapy in our clinic through a QI project. We found that screening is best accomplished by a single person who is able to screen all patients. This practice is now a standard of care in our clinic.

The full benefits of adult pneumococcal vaccination: A systematic review

BACKGROUND

Pneumococcal disease causes substantial morbidity and mortality, including among adults. Adult pneumococcal vaccines help to prevent these burdens, but they are underused. Accounting for the full benefits of adult pneumococcal vaccination may promote more rational resource allocation decisions with respect to adult pneumococcal vaccines.

OBJECTIVES

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic review to assess the extent to which the literature has empirically captured (e.g., through measurement or modeling) the full benefits of adult pneumococcal vaccination.

METHODS

We systematically searched PubMed and Embase to identify studies published between January 1, 2010 and April 10, 2016 that examine adult pneumococcal vaccination. We included articles if they captured any health or economic benefit of an adult pneumococcal vaccine administered to adults age ≥ 50 or ≥ 18 in risk groups. Finally, we summarized the literature by categorizing the types of benefits captured, the perspective taken, and the strength of the evidence presented. Our protocol is number 42016038335 in the PROSPERO International prospective register of systematic reviews.

RESULTS

We identified 5,857 papers and included 150 studies for analysis. While most capture health gains and healthcare cost savings, far fewer studies consider additional benefit categories, such as productivity gains. However, the studies with a broader approach still exhibit significant limitations; for example, many present only abstracts, while others offer no new measurements. Studies that examine the 13-valent pneumococcal conjugate vaccine focus more on broad economic benefits, but still have limitations.

CONCLUSIONS

This review highlights the need for more robust empirical accounting of the full benefits of adult pneumococcal vaccination. Literature outside this realm indicates that these broad benefits may be substantial. Failing to investigate the full benefits may lead society to undervalue vaccines' contributions and therefore underinvest in their development and adoption.

Functional immune responses to 11 non-PCV13 serotypes after immunization with a 23-valent pneumococcal polysaccharide vaccine in older adults

BACKGROUND

The 23-valent pneumococcal polysaccharide vaccine (PPSV23) has been recommended for adults aged ≥65years. To evaluate functional immune response against the additional 11 serotypes that are included in PPSV23, but not the 13-valent pneumococcal conjugate vaccine (PCV13), serotype-specific anti-pneumococcal antibodies were examined using an opsonophagocytic assay (OPA).

METHODS

Participants ≥65years of age that were naïve to the pneumococcal vaccine were enrolled. They were divided into two groups according to their age: group 1 (N=30; aged 65-74years) and group 2 (N=32; aged ≥75years). The functional antibody response prior to and 4weeks post-immunization with PPSV23 was determined, using a multiplexed OPA (MOPA) for 11 pneumococcal serotypes (2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20B, 22F, and 33F).

RESULTS

Geometric mean OPA titers (GMTs) to 11 serotypes were significantly increased in both groups post-immunization compared to those prior to immunization. The GMTs for all serotypes were not significantly different between the two groups after immunization. The proportion of subjects with OPA titers post-immunization of ≥8 and ≥64 was 93-100% and 80-100% for the 11 serotypes, respectively, while subjects with a ≥4-fold increase in OPA titers ranged from 9 to 90% for the 11 serotypes.

CONCLUSIONS

This study revealed that PPSV23 vaccination induced significant functional immune responses to 11 non-PCV13 serotypes in older adults. The MOPA has been shown to be a useful tool for future application in evaluating new PCVs in older adults. The clinical trial registration number is KCT 0001963 (CRIS, https://cris.nih.go.kr/cris/en/).

Impact of pneumococcal polysaccharide vaccine on incidence and mortality after pneumonia in adults aged ≥60 years-a population-based retrospective cohort study

OBJECTIVES

The 23-valent pneumococcal polysaccharide vaccine (PPV) is recommended for prevention of pneumococcal diseases in adults at risk. Few data exist on time-, age- and sex-dependent vaccine effectiveness on outcomes in pneumonia.

METHODS

We performed a population-based cohort study including adults ≥60 years of age (n = 738 927) based on statutory health insurance data from 2005 to 2011. Primary outcomes were all-cause pneumonia incidence and 30-day all-cause mortality. Pneumonia was identified by International Classification of Diseases, 10th Revision, German Modification (ICD-10-GM) codes, with ambulatory cases validated by antibiotic prescription within 7 days. The effect of PPV within 5 years was analysed after propensity score-based matching (three controls per case with PPV vaccination) including comorbidities, care status, age, sex and influenza vaccination. Evaluations were stratified by age group, sex and time of PPV.

RESULTS

Two-year incidence of all-cause pneumonia in 213 431 vaccinated individuals was 7501 (3.51%) of 213 431 vs. 23 243 (3.63%) of 640 293 in matched controls (difference -0.11, 95% confidence interval (CI) -0.22 to -0.002, p 0.046). After sex-dependent analysis, PPV effectiveness on pneumonia incidence was observed only in women (difference -0.15, 95% CI -0.28 to -0.02, p 0.02). Thirty-day mortality in vaccinated individuals with pneumonia was 1302 (17.36%) of 7501 vs. 4267 (18.96%) of 22 503 in matched controls (difference -1.60%, 95% CI -2.83 to -0.38, p 0.011). After analysis according to age group, significant mortality reduction was present only in adults aged 60 to 79 years (difference -2.31, 95% CI -3.79 to -0.83, p 0.002). Year of PPV vaccination showed no effect on outcomes.

CONCLUSIONS

The findings support consideration of sex and age dependence of PPV effectiveness in future studies.

Pneumonia and Streptococcus pneumoniae vaccine

Pneumonia is an inflammatory disease of the lung, responsible for high morbidity and mortality worldwide. It is caused by bacteria, viruses, fungi, or other microorganisms. Streptococcus pneumoniae, a gram-positive bacterium with over 90 serotypes, is the most common causative agent. Moreover, comorbid factors including heart failure, renal disease, and pulmonary disease could increase the risk of pneumococcal pneumonia. Since the advent of the pneumococcal vaccine in the 1980s, the incidence of pneumonia has decreased significantly. However, current vaccines confer only limited protection against serotypes included in the vaccine. Thus, to overcome this limitation, new types of pneumococcal vaccines have been sought and under clinical trials. In this review, we discuss pneumonia and summarize the various types of pneumococcal vaccines in progress.

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.

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.

Effectiveness of pneumococcal vaccines in preventing pneumonia in adults, a systematic review and meta-analyses of observational studies

INTRODUCTION

S. pneumoniae can cause a wide spectrum of diseases, including invasive pneumococcal disease and pneumonia. Two types of pneumococcal vaccines are indicated for use in adults: 23-valent pneumococcal polysaccharide vaccines (PPV23) and a 13-valent pneumococcal conjugate vaccine (PCV13).

OBJECTIVE

To systematically review the literature assessing pneumococcal vaccine effectiveness (VE) against community-acquired pneumonia (CAP) in adults among the general population, the immunocompromised and subjects with underlying risk factors in real-world settings.

METHODS

We searched for peer-reviewed observational studies published between 1980 and 2015 in Pubmed, SciELO or LILACS, with pneumococcal VE estimates against CAP, pneumococcal CAP or nonbacteremic pneumococcal CAP. Meta-analyses and meta-regression for VE against CAP requiring hospitalization in the general population was performed.

RESULTS

1159 unique articles were retrieved of which 33 were included. No studies evaluating PCV13 effectiveness were found. Wide ranges in PPV23 effectiveness estimates for any-CAP were observed among adults ≥65 years (-143% to 60%). The meta-analyzed VE estimate for any-CAP requiring hospitalization in the general population was 10.2% (95%CI: -12.6; 33.0). The meta-regression indicates that VE against any-CAP requiring hospitalization is significantly lower in studies with a maximum time since vaccination ≥60 months vs. <60 months and in countries with the pediatric PCV vaccine available on the private market. However, these results should be interpreted cautiously due to the high influence of two studies. The VE estimates for pneumococcal CAP hospitalization ranged from 32% (95%CI: -18; 61) to 51% (95%CI: 16; 71) in the general population.

CONCLUSIONS

Wide ranges in PPV23 effectiveness estimates for any-CAP were observed, likely due to a great diversity of study populations, circulation of S. pneumoniae serotypes, coverage of pediatric pneumococcal vaccination, case definition and time since vaccination. Despite some evidence for short-term protection, effectiveness of PPV23 against CAP was not consistent in the general population, the immunocompromised and subjects with underlying risk factors.

Cost-effectiveness of pneumococcal vaccination strategies for the elderly in Korea

Background

Although the 13-valent pneumococcal conjugate vaccine (PCV13) showed good efficacy against pneumococcal disease in the the CAPiTA trial, the 23-valent pneumococcal polysaccharide vaccination (PPSV23) program has been ongoing for older adults aged ≥ 65 years in Korea since May of 2013. This study aimed to evaluate the cost-effectiveness of the current vaccination strategy (a single-dose PPSV23 vaccination) compared to a single-dose PCV13 vaccination and sequential PCV13-PPSV23 vaccinations in the elderly population aged ≥ 65 years.

Methods

Using a Markov model, the incremental cost-effectiveness ratios (ICERs) of three vaccination strategies were assessed in a societal context. The transition probabilities, utility weights to estimate quality adjusted life year (QALY), and disease treatment costs were either calculated or cited from published data and the Health Insurance Review and Assessment Service. Simulations were performed in hypothetical cohorts of Korean adults aged ≥ 19 years. The vaccine effectiveness of PPSV23 was cited from a Cochrane Review report, while PCV13 effectiveness data were gathered from the CAPiTA trial.

Results

Current PPSV23 vaccination strategies were cost-effective (ICER, $25,786 per QALY). However, the administration of PCV13 as a substitute for PPSV23 was shown to be more cost-effective than PPSV23 vaccination (ICER, $797 per QALY). Sequential PCV13-PPSV23 vaccination was also more cost-effective than PPSV23 for elderly people aged ≥ 65 years. In sensitivity analysis assuming significant PPSV23 effectiveness (50%) against non-bacteremic pneumococcal pneumonia, the PCV13 vaccination strategy was superior to the PPSV23 vaccination strategy in terms of cost-effectiveness.

Conclusion

The results suggest that PCV13 vaccination is more cost-effective in elderly subjects aged ≥ 65 years compared to the current PPSV23 vaccination strategy. When complete data is obtained in 2018 on the maximal herd effects of childhood PCV13 immunization, the incidence of pneumococcal pneumonia and the cost-effectiveness of vaccination strategies need to be reassessed.

Indirect (herd) protection, following pneumococcal conjugated vaccines introduction: A systematic review of the literature

BACKGROUND

Pneumococcal diseases are major causes of morbidity among adults, especially those over 50years of age. While pneumococcal conjugated vaccines (PCV's) impact on pneumococcal disease rates among children is well established, the extent of its impact on adult pneumococcal related illness remains unclear. The aim of this systematic literature review was to describe the impact of PCV introduction to childhood national immunization programs worldwide on PCV-naive adult population.

METHODS

A systematic literature search was performed using the PubMed database. The search was limited to articles written in English and published between January 2000 and February 2016. Studies evaluating pneumococcal disease rates in individuals over 5years of age were included. Independent extraction of articles was performed by the two authors. Search terms included: Pneumococcal conjugated vaccine, herd, indirect, adults, and pneumonia.

RESULTS

Forty-nine articles meeting the selection criteria were identified, 39 regarding invasive pneumococcal disease (IPD, one on meningitis only), 8 regarding pneumonia, and 2 on both IPD and pneumonia. The majority of reports were from the US, UK and Canada. Considerable variability in the data sources, quality and completeness was observed. While most studies reported either statistically significant reduction or insignificant changes in IPD and pneumonia disease rates in adults following PCV nationwide implementation, few studies reported statistically significant increase in pneumococcal disease rates, these were mainly from countries with low PCV coverage rates and/or inadequate surveillance.

CONCLUSION

Invasive pneumococcal diseases and pneumonia rates among the adult population decreased in most countries following PCV introduction into the NIP. This indirect effect on older population seems to be dependent on PCV coverage rates and time from PCV nationwide implementation. Adults >65years old seem to benefit the most from PCV introduction.

Serotype Replacement in Adult Pneumococcal Pneumonia after the Introduction of Seven-Valent Pneumococcal Conjugate Vaccines for Children in Japan: a Systematic Literature Review and Pooled Data Analysis

Streptococcus pneumoniae is the major causative agent for adult pneumonia. Following the introduction of pneumococcal conjugate vaccines (PCV) for children, serotype replacement has been reported in adult invasive pneumococcal diseases but has not been well studied for cases of pneumococcal pneumonia in adults in Asia. To investigate serotype replacement in adult pneumococcal pneumonia in Japan, we conducted a systematic review of the literature across 5 databases using terms, including pneumococcus, serotype, their synonyms, and derivatives. After the assessment of the identified articles, data on the pneumococcal serotype distribution among adult pneumonia cases were extracted from relevant studies. Twenty-two studies were reviewed, and 4 relevant articles were included in the pooled data analysis. The proportion of the 7-valent PCV (PCV7)-covered serotypes from before and after the introduction of PCV7 for children (－18.1%, p ＜ 0.001) significantly decreased; moreover, the proportions of serotypes covered by PCV13 but not PCV7 (＋9.9%, p = 0.003) and those covered by the 23-valent polysaccharide vaccine but not PCV7 (＋9.4%, p = 0.007) significantly increased. Serotype replacement occurred in adult cases of pneumococcal pneumonia following vaccination of children with PCV7 in Japan. Further nationwide surveillance is warranted to investigate serotype replacement in the post-PCV13 phase.

Effectiveness of 23-valent pneumococcal polysaccharide vaccination in preventing community-acquired pneumonia hospitalization and severe outcomes in the elderly in Spain

Pneumococcal pneumonia is a serious cause of morbidity and mortality in the elderly, but investigation of the etiological agent of community-acquired pneumonia (CAP) is not possible in most hospitalized patients. The aim of this study was to estimate the effect of pneumococcal polysaccharide vaccination (PPSV23) in preventing CAP hospitalization and reducing the risk of intensive care unit admission (ICU) and fatal outcomes in hospitalized people aged ≥65 years. We made a multicenter case-control study in 20 Spanish hospitals during 2013-2014 and 2014-2015. We selected patients aged ≥65 years hospitalized with a diagnosis of pneumonia and controls matched by sex, age and date of hospitalization. Multivariate analysis was performed using conditional logistic regression to estimate vaccine effectiveness and unconditional logistic regression to evaluate the reduction in the risk of severe and fatal outcomes. 1895 cases and 1895 controls were included; 13.7% of cases and 14.4% of controls had received PPSV23 in the last five years. The effectiveness of PPSV23 in preventing CAP hospitalization was 15.2% (95% CI -3.1-30.3). The benefit of PPSV23 in avoiding ICU admission or death was 28.1% (95% CI -14.3-56.9) in all patients, 30.9% (95% CI -32.2-67.4) in immunocompetent patients and 26.9% (95% CI -38.6-64.8) in immunocompromised patients. In conclusion, PPSV23 showed a modest trend to avoidance of hospitalizations due to CAP and to the prevention of death or ICU admission in elderly patients hospitalized with a diagnosis of CAP.

Effectiveness of the 23-Valent Pneumococcal Polysaccharide Vaccine (PPV23) against Pneumococcal Disease in the Elderly: Systematic Review and Meta-Analysis

BACKGROUND

Routine vaccination of elderly people against pneumococcal diseases is recommended in many countries. National guidelines differ, recommending either the 23-valent polysaccharide vaccine (PPV23), the 13-valent conjugate vaccine (PCV13) or both. Considering the ongoing debate on the effectiveness of PPV23, we performed a systematic literature review and meta-analysis of the vaccine efficacy/effectiveness (VE) of PPV23 against invasive pneumococcal disease (IPD) and pneumococcal pneumonia in adults aged ≥60 years living in industrialized countries.

METHODS

We searched for pertinent clinical trials and observational studies in databases MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews. We assessed the risk of bias of individual studies using the Cochrane Risk of Bias tool for randomized controlled trials and the Newcastle-Ottawa Scale for observational studies. We rated the overall quality of the evidence by GRADE criteria. We performed meta-analyses of studies grouped by outcome and study design using random-effects models. We applied a sensitivity analysis excluding studies with high risk of bias.

RESULTS

We identified 17 eligible studies. Pooled VE against IPD (by any serotype) was 73% (95%CI: 10-92%) in four clinical trials, 45% (95%CI: 15-65%) in three cohort studies, and 59% (95%CI: 35-74%) in three case-control studies. After excluding studies with high risk of bias, pooled VE against pneumococcal pneumonia (by any serotype) was 64% (95%CI: 35-80%) in two clinical trials and 48% (95%CI: 25-63%) in two cohort studies. Higher VE estimates in trials (follow-up ~2.5 years) than in observational studies (follow-up ~5 years) may indicate waning protection. Unlike previous meta-analyses, we excluded two trials with high risk of bias regarding the outcome pneumococcal pneumonia, because diagnosis was based on serologic methods with insufficient specificity.

CONCLUSIONS

Our meta-analysis revealed significant VE of PPV23 against both IPD and pneumococcal pneumonia by any serotype in the elderly, comparable to the efficacy of PCV13 against vaccine-serotype disease in a recent clinical trial in elderly people. Due to its broader serotype coverage and the decrease of PCV13 serotypes among adults resulting from routine infant immunization with PCV13, PPV23 continues to play an important role for protecting adults against IPD and pneumococcal pneumonia.

Prevention of Community-Acquired Pneumonia with Available Pneumococcal Vaccines

Community-acquired pneumonia (CAP) places a considerable burden on society. A substantial number of pediatric and adult CAP cases are due to Streptococcus pneumoniae, but fortunately there are effective vaccines available that have a significant impact on CAP-related medical, social, and economic problems. The main aim of this paper is to evaluate the published evidence concerning the impact of pneumococcal vaccines on the prevention of CAP in children and adults. Available data indicate that pneumococcal conjugate vaccines (PCVs) are effective in children, reducing all-cause CAP cases and bacteremic and nonbacteremic CAP cases. Moreover, at least for PCV7 and PCV13, vaccination of children is effective in reducing the incidence of CAP among adults. Recently use of PCV13 in adults alone or in combination with the pneumococcal polysaccharide vaccine has been suggested and further studies can better define its effectiveness in this group of subjects. The only relevant problem for PCV13 is the risk of a second replacement phenomenon, which might significantly reduce its real efficacy in clinical practice. Protein-based pneumococcal vaccines might be a possible solution to this problem.

Effectiveness, immunogenicity and safety of 23-valent pneumococcal polysaccharide vaccine revaccinations in the elderly: a systematic review

Background

In many industrialized countries routine vaccination with the 23-valent pneumococcal polysaccharide vaccine (PPSV-23) is recommended to prevent pneumococcal disease in the elderly. However, vaccine-induced immunity wanes after a few years, and there are controversies around revaccination with PPSV-23. Here, we systematically assessed the effectiveness and safety of PPSV-23 revaccination.

Method

We conducted a systematic literature review in MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials from inception to June 2015. We included all study types that compared effectiveness, immunogenicity and/or safety of PPSV-23 as a primary vs. a revaccination dose in persons aged 50 years and older. With respect to immunogenicity, we calculated the ratio of geometric mean antibody concentrations and opsonophagocytic indexes at identical time-points after primary and revaccination. Additionally, we compared rates and severity of adverse events (AEs) after primary and revaccination.

Results

We included 14 observational studies. 10 studies had a prospective design and analysed data on (i) the same individuals after a first and a second dose of PPSV-23 given 1 to 10 years later (n = 5) or (ii) two groups consisting of participants receiving PPSV-23 who were either vaccine-naïve or had received a first PPSV-23 dose 3 to 13 years earlier (n = 5). Three studies used electronic data bases to compare AEs after primary vs. revaccination doses of PPSV-23 after 1 to 10 years and one study had a cross-sectional design. Number of participants in the non-register-based and register-based studies ranged from 29 to 1414 and 360 to 316,000, respectively. 11 out of 14 included studies were at high risk of bias, three studies had an unclear risk of bias. None of the studies reported data on clinical effectiveness. Immunogenicity studies revealed that during the first two months antibody levels tended to be lower after revaccination as compared to primary vaccination. Thereafter, no obvious differences in antibody levels were observed. Compared to primary vaccination, revaccination was associated with an increased risk of local and systemic AEs, which, however, were usually mild and self-limiting. The risk and severity of AEs appeared to decrease with longer intervals between primary and revaccination.

Conclusion

Data comparing the effectiveness of primary vs. revaccination with PPSV-23 are still lacking, because there are no studies with clinical endpoints. Data from observational studies indicates that revaccination with PPSV-23 is likely to induce long-term antibody levels that are comparable to those after primary vaccination. Given the high disease burden and the waning of vaccine-induced immunity, revaccination with PPSV-23 could be considered in the elderly. The increased risk of local and systemic AEs can likely be mitigated when giving revaccination at least five years after the primary dose. Adequately powered randomized controlled trials using clinical endpoints are urgently needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2040-y) contains supplementary material, which is available to authorized users.

Evaluating the costs and benefits of pneumococcal vaccination in adults

INTRODUCTION

Pneumococcal infection is a public health concern that disproportionately affects the young, the elderly, and the immunocompromised. There is an open debate on the implementation of polysaccharide and/or conjugate vaccines for pneumococcal diseases in adults and the elderly in many countries. The aim of this paper is to systematically review the economic profile of pneumococcal vaccines in adults in terms of costs and benefits. Areas covered: The search for economic studies on pneumococcal vaccination was carried out in Pubmed, Embase, Scopus, and the HTA and NHS EED databases and through a manual search in journals dealing with economic evaluations. We included original articles and reviews with economic evaluation of polysaccharide 23-valent (PPV23) and/or conjugate pneumococcal vaccine 13-valent (PCV13) use in adults, the elderly, and at-risk groups to provide a systematic review of economical evaluation. Expert commentary: Pneumococcal vaccination is strongly recommended for all adults, especially subjects at risk and the elderly. Pneumococcal vaccination with PCV13 or PPV23 in adults is good value for money and should be a priority for the decision-makers. The main issue is how vaccination could be offered.

Equity in disease prevention: Vaccines for the older adults - a national workshop, Australia 2014

On the 20th June, 2014 the National Health and Medical Research Council's Centre for Research Excellence in Population Health "Immunisation in under Studied and Special Risk Populations", in collaboration with the Public Health Association of Australia, hosted a workshop "Equity in disease prevention: vaccines for the older adults". The workshop featured international and national speakers on ageing and vaccinology. The workshop was attended by health service providers, stakeholders in immunisation, ageing, primary care, researchers, government and non-government organisations, community representatives, and advocacy groups. The aims of the workshop were to: provide an update on the latest evidence around immunisation for the older adults; address barriers for prevention of infection in the older adults; and identify immunisation needs of these groups and provide recommendations to inform policy. There is a gap in immunisation coverage of funded vaccines between adults and infants. The workshop reviewed provider misconceptions, lack of Randomised Control Trials (RCT) and cost-effectiveness data in the frail elderly, loss of autonomy, value judgements and ageism in health care and the need for an adult vaccination register. Workshop recommendations included recognising the right of elderly people to prevention, the need for promotion in the community and amongst healthcare workers of the high burden of vaccine preventable diseases and the need to achieve high levels of vaccination coverage, in older adults and in health workers involved in their care. Research into new vaccine strategies for older adults which address poor coverage, provider attitudes and immunosenescence is a priority. A well designed national register for tracking vaccinations in older adults is a vital and basic requirement for a successful adult immunisation program. Eliminating financial barriers, by addressing inequities in the mechanisms for funding and subsidising vaccines for the older adults compared to those for children, is important to improve equity of access and vaccination coverage. Vaccination coverage rates should be included in quality indicators of care in residential aged care for older adults. Vaccination is key to healthy ageing, and there is a need to focus on reducing the immunisation gap between adults and children.

What do we know about the cost-effectiveness of pneumococcal conjugate vaccination in older adults?

The cost-effectiveness of 13-type pneumococcal conjugate vaccine (PCV13) use in older adults, and the relative merits when compared to the 23-type polysaccharide pneumococcal vaccine (PPV23), has been a topic of much debate. Although a number of economics evaluations have been conducted many of these were completed before the availability of critical data on PCV13 efficacy in older adults. Recent studies using this data have found conflicting results. This may in part reflect differences in the level of herd protection from infant pneumococcal vaccination programs in different countries. The costs and benefits of pneumococcal vaccination in adults are likely to rest on several critical parameters: the magnitude pneumococcal disease in older adults and the serotypes responsible for it, the efficacy of each vaccine against invasive and non-invasive pneumonia, the duration of vaccine protection, and differences in vaccine price. The ongoing changes in pneumococcal disease patterns highlight the need for economic evaluations to use recent serotype-specific disease estimates from the setting under consideration. In countries that do recommend PCV13 use in adults, post-implementation economic evaluation (using data from after a program is implemented) may be useful to help inform potential future changes to vaccine recommendations as well as the maximum price that should be paid for the vaccines in future negotiations.

Indirect Effects of Pneumococcal Conjugate Vaccines in National Immunization Programs for Children on Adult Pneumococcal Disease

The pneumococcal conjugate vaccine (PCV) was developed to overcome the limitations of the pneumococcal polysaccharide vaccine, which produces poor immunogenicity in infants younger than 2 years. As many countries have included PCVs in national immunization programs for children, the incidence of invasive pneumococcal disease caused by vaccine type Streptococcus pneumoniae has declined markedly, not only among the vaccinated pediatric population, but also among unvaccinated adults. In this review, we present a concise overview of the indirect effects of mass pediatric PCV immunization on unvaccinated adults.