Safety and immunogenicity of sequential pneumococcal immunization in preschool asthmatics

Anti-IL-5 therapies for asthma

BACKGROUND

This is the second update of previously published reviews in the Cochrane Library (2015, first update 2017). Interleukin-5 (IL-5) is the main cytokine involved in the proliferation, maturation, activation and survival of eosinophils, which cause airway inflammation and are a classic feature of asthma. Studies of monoclonal antibodies targeting IL-5 or its receptor (IL-5R) suggest they reduce asthma exacerbations, improve health-related quality of life (HRQoL) and lung function in appropriately selected patients, justifying their inclusion in the latest guidelines.

OBJECTIVES

To compare the effects of therapies targeting IL-5 signalling (anti-IL-5 or anti-IL-5Rα) with placebo on exacerbations, health-related quality-of-life (HRQoL) measures and lung function in adults and children with chronic asthma, and specifically in those with eosinophilic asthma refractory to existing treatments.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two trials registers, manufacturers' websites, and reference lists of included studies. The most recent search was 7 February 2022.

SELECTION CRITERIA

We included randomised controlled trials comparing mepolizumab, reslizumab and benralizumab versus placebo in adults and children with asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and analysed outcomes using a random-effects model. We used standard methods expected by Cochrane.

MAIN RESULTS

Seventeen studies on about 7600 participants met the inclusion criteria. Six used mepolizumab, five used reslizumab, and six used benralizumab. One study using benralizumab was terminated early due to sponsor decision and contributed no data. The studies were predominantly on people with severe eosinophilic asthma, which was similarly but variably defined. One was in children aged 6 to 17 years; nine others included children over 12 years but did not report results by age group separately. We deemed the overall risk of bias to be low, with all studies contributing data of robust methodology. We considered the certainty of the evidence for all comparisons to be high overall using the GRADE scheme, except for intravenous (IV) mepolizumab and subcutaneous (SC) reslizumab because these are not currently licensed delivery routes. The anti-IL-5 treatments assessed reduced rates of 'clinically significant' asthma exacerbation (defined by treatment with systemic corticosteroids for three days or more) by approximately half in participants with severe eosinophilic asthma on standard care (at least medium-dose inhaled corticosteroids (ICS)) with poorly controlled disease (either two or more exacerbations in the preceding year or Asthma Control Questionnaire (ACQ) score of 1.5 or more), except for reslizumab SC. The rate ratios for these effects were 0.45 (95% confidence interval (CI) 0.36 to 0.55; high-certainty evidence) for mepolizumab SC, 0.53 (95% CI 0.44 to 0.64; moderate-certainty evidence) for mepolizumab IV, 0.43 (95% CI 0.33 to 0.55; high-certainty evidence) for reslizumab IV, and 0.59 (95% CI 0.52 to 0.66; high-certainty evidence) for benralizumab SC. Non-eosinophilic participants treated with benralizumab also showed a significant reduction in exacerbation rates, an effect not seen with reslizumab IV, albeit in only one study. No data were available for non-eosinophilic participants treated with mepolizumab. There were improvements in validated HRQoL scores with all anti-IL-5 agents in severe eosinophilic asthma. This met the minimum clinically important difference (MCID) for the broader St. George's Respiratory Questionnaire (SGRQ; 4-point change) for benralizumab only, but the improvement in the ACQ and Asthma Quality of Life Questionnaire (AQLQ), which focus on asthma symptoms, fell short of the MCID (0.5 point change for both ACQ and AQLQ) for all of the interventions. The evidence for an improvement in HRQoL scores in non-eosinophilic participants treated with benralizumab and reslizumab was weak, but the tests for subgroup difference were negative. All anti-IL-5 treatments produced small improvements in mean pre-bronchodilator forced expiratory flow in one second (FEV1) of between 0.08 L and 0.15 L in eosinophilic participants, which may not be sufficient to be detected by patients. There were no excess serious adverse events with any anti-IL-5 treatment; in fact, there was a reduction in such events with benralizumab, likely arising from fewer asthma-related hospital admissions. There was no difference compared to placebo in adverse events leading to discontinuation with mepolizumab or reslizumab, but significantly more discontinued benralizumab than placebo, although the absolute numbers were small (42/2026 (2.1%) benralizumab versus 11/1227 (0.9%) placebo). The implications for efficacy or adverse events are unclear.

AUTHORS' CONCLUSIONS

Overall this analysis supports the use of anti-IL-5 treatments as an adjunct to standard care in people with severe eosinophilic asthma and poor symptom control. These treatments roughly halve the rate of asthma exacerbations in this population. There is limited evidence for improved HRQoL scores and lung function, which may not meet clinically detectable levels. The studies did not report safety concerns for mepolizumab or reslizumab, or any excess serious adverse events with benralizumab, although there remains a question over adverse events significant enough to prompt discontinuation. Further research is needed on biomarkers for assessing treatment response, optimal duration and long-term effects of treatment, risk of relapse on withdrawal, non-eosinophilic patients, children (particularly under 12 years), comparing anti-IL-5 treatments to each other and, in patients meeting relevant eligibility criteria, to other biological (monoclonal antibody) therapies. For benralizumab, future studies should closely monitor rates of adverse events prompting discontinuation.

Impact of pneumococcal vaccine response on asthma exacerbation frequency in young children

INTRODUCTION

Chronic asthma is a heterogeneous disease, and increased eosinophils have been shown to predict increased asthma exacerbations, especially in adults. Recent recommendations suggest the need for supplemental PPV-23 vaccination in older children with chronic asthma.

METHODS

To investigate differences in preschool asthma, our case-cohort study comprised of 127 children, mean age 47 months (32-65), with a history of asthma exacerbations requiring more than three courses of systemic steroid bursts and more than six antibiotics courses in the previous year.

RESULTS

At baseline, mean antibody titer response to Streptococcus pneumoniae was decreased at 2.6 ± 2 out of 14 serotypes, despite prior complete pneumococcal conjugate vaccine (PCV) vaccinations. All children were readministered pneumococcal vaccinations with PCV-13 booster and/or PPSV-23. Mean postvaccination pneumococcal vaccine (PV) titer response was 16 ± 5 out of 23 serotypes. After contacting 91 parents/caretakers, 75 responded with less frequency of corticosteroids and antibiotic use for asthma exacerbations after PV. This group had baseline eosinophil counts of 211 ± 36/µL, while those without improvement were significantly higher at 371 ± 123/µL,*P < .05. There were no significant differences (P > .05) between the two groups from other baseline measures including demography or atopic status.

CONCLUSIONS

This subset of children with exacerbation-prone asthma had poor antibody titer response to Streptococcus pneumoniae, even with prior complete PCV-13 immunization. Identification of low antibody responses to PV serotypes may provide a targeted therapeutic approach to reduce wheezing exacerbations in a precise asthma phenotype in children.

Asthma and the Risk of Invasive Pneumococcal Disease: A Meta-analysis

CONTEXT

Invasive pneumococcal disease (IPD) and pneumonia are a leading cause of morbidity and mortality throughout the world, and asthma is the most common chronic disease of childhood.

OBJECTIVE

To evaluate the risk of IPD or pneumonia among children with asthma after the introduction of pneumococcal conjugate vaccines (PCVs).

DATA SOURCES

Four electronic databases were searched.

STUDY SELECTION

We selected all cohorts or case-control studies of IPD and pneumonia in populations who already received PCV (largely 7-valent pneumococcal conjugate vaccine), but not 23-valent pneumococcal polysaccharide, in which authors reported data for children with asthma and in which healthy controls were included, without language restriction.

DATA EXTRACTION

Two reviewers independently reviewed all studies. Primary outcomes were occurrence of IPD and pneumonia. Secondary outcomes included mortality, hospital admissions, hospital length of stay, ICU admission, respiratory support, costs, and additional medication use.

RESULTS

Five studies met inclusion criteria; of those, 3 retrospective cohorts (∼26 million person-years) and 1 case-control study (N = 3294 children) qualified for the meta-analysis. Children with asthma had 90% higher odds of IPD than healthy controls (odds ratio = 1.90; 95% confidence interval = 1.63-2.11; I² = 1.7%). Pneumonia was also more frequent among children with asthma than among controls, and 1 study reported that pneumonia-associated costs increased by asthma severity.

LIMITATIONS

None of the identified studies had information of asthma therapy or compliance.

CONCLUSIONS

Despite PCV vaccination, children with asthma continue to have a higher risk of IPD than children without asthma. Further research is needed to assess the need for supplemental 23-valent pneumococcal polysaccharide vaccination in children with asthma, regardless of their use of oral steroids.

Why are people with asthma susceptible to pneumonia? A review of factors related to upper airway bacteria

Asthma and pneumonia are common respiratory conditions globally, affecting individuals of all ages. Streptococcus pneumoniae is the predominant bacterial cause of pneumonia, with nasopharyngeal carriage an important step towards invasive and pulmonary disease. Vaccines provide individual protection, and also prevent nasopharyngeal carriage, providing herd immunity. Asthma is associated with an increased risk of pneumonia, but there is limited information on the underlying mechanism of this predisposition. Both asthma and its treatment may conceivably alter propensity to, and density of, carriage through an altered epithelial microenvironment driven by disease-related inflammation or treatment-related immunomodulation, for example with inhaled corticosteroids. The relative importance of these factors could impact the efficacy of vaccines in this vulnerable patient population. In this review, we summarize the evidence for an increased risk of pneumonia in asthma, and discuss factors affecting nasopharyngeal carriage in the context of current guidelines for pneumococcal vaccination.

Immunogenicity and persistence of the 13-valent Pneumococcal Conjugate Vaccine (PCV13) in patients with untreated Smoldering Multiple Myeloma (SMM): A pilot study

Smoldering multiple myeloma (SMM) is an asymptomatic clonal plasma cell disorder that frequently progress to multiple myeloma (MM), a disease at high risk of pneumococcal infections. Moreover, if the polysaccharide vaccine is poorly immunogenic in MM, the 13-valent conjugated vaccine has never been tested in clonal plasma cell disorders. We evaluated its immunogenicity for 7 serotypes in 20 patients ≥ 50 years of age with smoldering multiple myeloma (SMM) pre and post routine-vaccination with PCV13.

Concentrations of IgG specific for 7 serotypes were measured at baseline, 1, 6, and 12 months after vaccination by standardized ELISA and an Opsonophagocytic Assay (OPA). The primary endpoint was the proportion of patients responding to at least 5 of the 7 serotypes by ELISA at one month.

At 1 month post vaccination, 12 patients (60%) were responders by ELISA, among whom 8 were also responders by OPA. At 6 months, 6 (30% of total) of the 12 responders had persistent immunity, and only 2 (10% of total) at 12 months. These results suggested a partial response in this population and a rapid decrease in antibody levels in the first months of vaccination.

Although one injection of the 13-valent pneumococcal conjugate vaccine is immunogenic in some patients with SMM, the response is transient. Repeated injections are likely to be needed for effective and sustained protection.

Anti-IL5 therapies for asthma

BACKGROUND

This review is the first update of a previously published review in The Cochrane Library (Issue 7, 2015). Interleukin-5 (IL-5) is the main cytokine involved in the activation of eosinophils, which cause airway inflammation and are a classic feature of asthma. Monoclonal antibodies targeting IL-5 or its receptor (IL-5R) have been developed, with recent studies suggesting that they reduce asthma exacerbations, improve health-related quality of life (HRQoL) and lung function. These are being incorporated into asthma guidelines.

OBJECTIVES

To compare the effects of therapies targeting IL-5 signalling (anti-IL-5 or anti-IL-5Rα) with placebo on exacerbations, health-related qualify of life (HRQoL) measures, and lung function in adults and children with chronic asthma, and specifically in those with eosinophilic asthma refractory to existing treatments.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, clinical trials registries, manufacturers' websites, and reference lists of included studies. The most recent search was March 2017.

SELECTION CRITERIA

We included randomised controlled trials comparing mepolizumab, reslizumab and benralizumab versus placebo in adults and children with asthma.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and analysed outcomes using a random-effects model. We used standard methods expected by Cochrane.

MAIN RESULTS

Thirteen studies on 6000 participants met the inclusion criteria. Four used mepolizumab, four used reslizumab, and five used benralizumab. One study in benralizumab was terminated early due to sponsor decision and contributed no data. The studies were predominantly on people with severe eosinophilic asthma, which was similarly but variably defined. Eight included children over 12 years but these results were not reported separately. We deemed the risk of bias to be low, with all studies contributing data being of robust methodology. We considered the quality of the evidence for all comparisons to be high overall using the GRADE scheme, with the exception of intravenous mepolizumab because this is not currently a licensed delivery route.All of the anti-IL-5 treatments assessed reduced rates of 'clinically significant' asthma exacerbation (defined by treatment with systemic corticosteroids for three days or more) by approximately half in participants with severe eosinophilic asthma on standard of care (at least medium-dose inhaled corticosteroids (ICS)) with poorly controlled disease (either two or more exacerbations in the preceding year or Asthma Control Questionnaire (ACQ) 1.5 or more). Non-eosinophilic participants treated with benralizumab also showed a significant reduction in exacerbation rates, but no data were available for non-eosinophilic participants, and mepolizumab or reslizumab.We saw modest improvements in validated HRQoL scores with all anti-IL-5 agents in severe eosinophilic asthma. However these did not exceed the minimum clinically important difference for ACQ and Asthma Quality of Life Questionnaire (AQLQ), with St. George's Respiratory Questionnaire (SGRQ) only assessed in two studies. The improvement in HRQoL scores in non-eosinophilic participants treated with benralizumab, the only intervention for which data were available in this subset, was not statistically significant, but the test for subgroup difference was negative.All anti-IL-5 treatments produced a small but statistically significant improvement in mean pre-bronchodilator forced expiratory flow in one second (FEV1) of between 0.08 L and 0.11 L.There were no excess serious adverse events with any anti-IL-5 treatment, and indeed a reduction in favour of mepolizumab that could be due to a beneficial effect on asthma-related serious adverse events. There was no difference compared to placebo in adverse events leading to discontinuation with mepolizumab or reslizumab, but significantly more discontinued benralizumab than placebo, although the absolute numbers were small (36/1599 benralizumab versus 9/998 placebo).Mepolizumab, reslizumab and benralizumab all markedly reduced blood eosinophils, but benralizumab resulted in almost complete depletion, whereas a small number remained with mepolizumab and reslizumab. The implications for efficacy and/or adverse events are unclear.

AUTHORS' CONCLUSIONS

Overall our study supports the use of anti-IL-5 treatments as an adjunct to standard of care in people with severe eosinophilic asthma and poor control. These treatments roughly halve the rate of asthma exacerbations in this population. There is limited evidence for improved HRQoL scores and lung function, which may not meet clinically detectable levels. There were no safety concerns regarding mepolizumab or reslizumab, and no excess serious adverse events with benralizumab, although there remains a question over adverse events significant enough to prompt discontinuation.Further research is needed on biomarkers for assessing treatment response, optimal duration and long-term effects of treatment, risk of relapse on withdrawal, non-eosinophilic patients, children (particularly under 12 years), and comparing anti-IL-5 treatments to each other and, in people eligible for both, to anti-immunoglobulin E. For benralizumab, future studies should closely monitor rates of adverse events prompting discontinuation.

Mepolizumab versus placebo for asthma

BACKGROUND

Mepolizumab is a human monoclonal antibody against interleukin-5 (IL-5), the main cytokine involved in the activation of eosinophils, which in turn causes airway inflammation. Recent studies have suggested these agents may have a role in reducing exacerbations and improving health-related quality of life (HRQoL). There are no recommendations for the use of mepolizumab in adults or children in the recent update of the BTS/SIGN guidelines (BTS/SIGN 2014).

OBJECTIVES

To compare the effects of mepolizumab with placebo on exacerbations and HRQoL in adults and children with chronic asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Register (CAGR) of trials, clinical trial registries, manufacturers' websites and the reference lists of included studies. Searches were conducted in November 2013 and updated in November 2014.

SELECTION CRITERIA

We included randomised controlled trials comparing mepolizumab versus placebo in adults and children with asthma.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and analysed outcomes using a random-effects model. We used standard methods expected by The Cochrane Collaboration.

MAIN RESULTS

Eight studies on 1707 participants met the inclusion criteria. Only two studies included children (over 12 years of age), but they did not report separate findings for the adolescents. Seven studies involved intravenous mepolizumab alone; one included a subcutaneous arm. There was heterogeneity in the severity and clinical pattern of asthma among the participants in the eight studies, varying from mild to moderate atopic asthma, to persistent asthma and eosinophilic asthma with recurrent exacerbations. Selection bias was a concern in several of the studies included in this review.Four trials compared intravenous mepolizumab to placebo in relation to HRQoL. Two studies measured scores from the Asthma Quality of Life Questionnaire (AQLQ), which showed a non-significant difference between mepolizumab and placebo (mean difference (MD) 0.21, 95% confidence interval (CI) - 0.01 to 0.44; participants = 682), in the direction favouring mepolizumab. The third study used the St. George's Respiratory Questionnaire (SGRQ) and found a significant difference between mepolizumab and placebo (MD 6.40, 95% CI 3.15 to 9.65; participants = 576), which indicated a clinically important benefit favouring mepolizumab. A fourth study noted that there was no significant difference but did not provide any data. The two studies in people with eosinophilic asthma showed a reduction in clinically significant exacerbation rates (Risk Ratio 0.52, 95% CI 0.43 to 0.64; participants = 690). However, an analysis of four studies that were not confined to people with eosinophilic asthma indicated considerable heterogeneity and no significant difference in people with one or more exacerbations between mepolizumab and placebo using a random-effects model (Risk Ratio 0.67, 95% CI 0.34 to 1.31; participants = 468; I(2) = 59%).The analysis of serious adverse events indicated a significant difference favouring mepolizumab (Risk ratio 0.49, 95% CI 0.30 to 0.80; participants = 1441; studies = 5; I(2) = 0%). It was not possible to combine the results for adverse events, and we deemed the quality of this evidence to be low.A single study compared subcutaneous mepolizumab to placebo in 385 adults with severe eosinophilic asthma and found an improvement in HRQoL scores and a reduction in asthma exacerbations, including exacerbations requiring admission to hospital.

AUTHORS' CONCLUSIONS

It is not possible to draw firm conclusions from this review with respect to the role of mepolizumab in patients with asthma. Our confidence in the results of this review are limited by the fact that the intravenous route is not currently licensed for mepolizumab, and the evidence for the currently licenced subcutaneous route is limited to a single study in participants with severe eosinophilic asthma.The currently available studies provide evidence that mepolizumab can lead to an improvement in health-related quality of life scores and reduce asthma exacerbations in people with severe eosinophilic asthma.Further research is needed to clarify which subgroups of patients with asthma could potentially benefit from this treatment. Dosage, ideal dosing regimens and duration of treatment need to be clarified, as the studies included in this review differed in their protocols. There are no studies reporting results from children, so we cannot comment on treatment for this age group. At the present time, larger studies using licenced treatment regimens are required to establish the role of mepolizumab in the treatment of severe asthma.

Paediatric asthma and pneumococcal vaccination

Asthma is a clinical condition that has only recently been considered a risk factor for the development of pneumococcal infections. In the most recent guidelines concerning the use of pneumococcal vaccines, the Advisory Committee on Immunisation Practices recommends pneumococcal vaccination only when children with asthma aged <71 months are treated with high-dose corticosteroids, whereas the same Committee clearly indicates that asthma (without any definition of severity or treatment) is a reason for systematic pneumococcal vaccination in adults. It is also unclear which pneumococcal vaccine should be used and how to face the problem of booster doses. The main aim of this paper is to describe what is known about the real risk of pneumococcal infections in children with asthma, and discuss the unsolved problems regarding the paediatric use of pneumococcal vaccines. There are few published data regarding pneumococcal colonisation and the burden of pneumococcal disease in asthmatic children and adolescents, and none at all concerning the relationship between paediatric asthma and immune responses to pneumococcal vaccines. Further studies are therefore essential to assure that children and adolescents with asthma receive the best protection against pneumococcal diseases.

Reference ranges and cutoff levels of pneumococcal antibody global serum assays (IgG and IgG2) and specific antibodies in healthy children and adults

Pneumococcal antibodies represent the acquisition of natural immunity. Determination of pneumococcal antibodies is an important screening tool for immunodeficiencies. Our study generated reference ranges and cutoff levels for pneumococcal antibody global serum assays correlated to a specific pneumococcal antibody ELISA. Specific pneumococcal antibody levels were measured from 457 children undergoing elective surgery and 46 healthy adult volunteers (88 with previous pneumococcal immunization from both groups), 22 severe immunodeficient subjects with ataxia telangiectasia (A-T, negative controls), and age-matched 36 healthy allergic asthmatics. We determined a representative panel of serotype-specific pneumococcal antibodies (serotype 4, 5, 6B, 7F, 14, 18C, 19F, 23F) by ELISA and global pneumococcal IgG and IgG2 antibodies by EIA. In vaccine-naïve healthy subjects, initial pneumococcal IgG geometric mean concentrations of 13.1 μg/ml were low in the first year of life and increased over the time, reaching adult levels (70.5 μg/ml) at age 8-12 years. In parallel, IgG2 antibodies increased from 20.7 % (0.5-1 year old) to adult proportions (>30 %) in preschoolers. Correlation between the pneumococcal IgG screening assay and specific pneumococcal antibody levels was acceptable (Pearson's coefficient r = 0.4455; p = 0.001). Cutoff levels showed high sensitivity, whereas specificity was high to moderate calculated from correlations with the specific ELISA. We provide reference ranges and cutoff levels for the interpretation of specific antibody determinations in the clinical setting. The global pneumococcal IgG/IgG2 assay is a suitable screening tool and correlates with the ELISA serotype-specific pneumococcal antibodies. However, results below our cutoff values should be re-evaluated by serotype-specific ELISA testing.

Safety and immunogenicity of the 23-valent pneumococcal polysaccharide vaccine at 12 months of age, following one, two, or three doses of the 7-valent pneumococcal conjugate vaccine in infancy

Fijian infants aged 6 weeks were stratified by ethnicity and randomized to receive 0, 1, 2, or 3 PCV-7 doses with or without the 23-valent pneumococcal polysaccharide vaccine (PPV-23) at 12 months. Strong booster effects for all 7 PCV-7 serotypes were elicited, and for 4/7 serotypes these responses were highest in the single PCV-7 group. There were fourfold rises in GMC for all non-PCV-7 serotypes. By 17 months the PPV-23 group still had significantly higher GMC (each p<0.001) for all serotypes. The PPV-23 was well tolerated and induced excellent responses for all serotypes which were greatest in the single PCV-7 group.

Pneumococcal vaccine for asthma

BACKGROUND

Infection with Streptococcus pneumoniae is an important cause of pneumonia and other serious illnesses, particularly amongst those with certain high-risk medical conditions such as asthma. Although pneumococcal vaccine is routinely advocated for people with asthma, there is uncertainty about the evidence base that underpins this recommendation.

OBJECTIVES

To determine the efficacy of pneumococcal vaccine in reducing mortality or morbidity from pneumococcal disease in asthmatics.

SEARCH STRATEGY

Randomised controlled trials were identified using the Cochrane Airways Group's register derived from MEDLINE, EMBASE, and CINAHL electronic databases and hand searched respiratory journals and meeting abstracts.

SELECTION CRITERIA

Randomised controlled trials, with or without blinding, in which pneumococcal vaccine has been compared with placebo or no treatment in people with clinician diagnosed asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers independently reviewed all abstracts and full papers of all articles of potential relevance were retrieved. Methodological quality was rated using the Cochrane approach and the Jadad rating scale. Data extraction was performed by one reviewer and checked independently by a second. We planned to perform quantitative analyses of outcomes on an intention-to-treat basis, where possible.

MAIN RESULTS

Of the three papers retrieved, only one satisfied the inclusion criteria and the methodological quality of this study was low (unblinded and inadequate allocation concealment). None of the data could be aggregated in a meta-analysis. Comparisons in a sub-set of 30 asthmatic children prone to recurrent episodes of otitis media, showed that pneumococcal vaccination decreased the incidence of acute asthma exacerbations from 10 to 7 (per child per year).

REVIEWER'S CONCLUSIONS

This review found very limited evidence to support the routine use of pneumococcal vaccine in people with asthma. A randomised trial of vaccine efficacy in children and adults with asthma is needed.