Pneumococcal vaccination

Strategies for pneumococcal vaccination in older adults in the coming era

Pneumonia, predominantly caused by Streptococcus pneumoniae, remains a leading cause of global mortality. The 23-valent Pneumococcal polysaccharide vaccine (PPSV23) and conjugate vaccines (PCVs) are vital measures to fight against it. This paper discussed the changes in pneumococcal vaccination strategies, particularly for older adults, as vaccine effectiveness and epidemiological patterns shift. While PPSV23 maintains effectiveness against invasive pneumococcal disease (IPD), its effectiveness against pneumococcal pneumonia is declining. Conversely, PCV13 consistently demonstrates effectiveness against both IPD and pneumonia. Consequently, the US Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recommends using PCVs, notably PCV20 and PCV15, over PPSV23. Japanese studies indicate a change in the efficacy/effectiveness of PPSV23 following PCV introduction in children, likely owing to serotype replacement and herd immunity. Additionally, recent data reveals a plateau in the reduction of PCV13 and PPSV23-covered serotypes, posing a challenge to current strategies. This paper indicates a paradigm shift in pneumonia management, acknowledging its chronic nature and potential to exacerbate other diseases. The future of pneumococcal vaccination lies in broader serotype coverage through PCVs, adapting to serotype changes driven by childhood vaccination programs. Furthermore, continuous research and vaccine development are crucial in this evolving field.

Hospitalization and Mortality Due to Infection Among Children and Adolescents With Systemic Lupus Erythematosus in the United States

OBJECTIVE

We aimed to determine the frequency and types of infections in hospitalized children with childhood-onset systemic lupus erythematosus (cSLE), and to identify risk factors for intensive care unit (ICU) admission and mortality.

METHODS

We conducted a retrospective study of youth aged 2 to 21 years using International Classification of Diseases (ICD) codes for SLE assigned during admission to a hospital participating in the Pediatric Health Information System, a database of United States children's hospitals, from 2009 to 2021. Generalized linear mixed effects models were used to identify risk factors for ICU admission and mortality among children hospitalized with infection.

RESULTS

We identified 8588 children with cSLE and ≥ 1 hospitalization. Among this cohort, there were 26,269 hospitalizations, of which 13% had codes for infections, a proportion that increased over time (P = 0.04). Bacterial pneumonia was the most common hospitalized infection. In-hospital mortality occurred in 0.4% (n = 103) of cSLE hospitalizations for any indication and 2% of hospitalizations for infection (n = 60). The highest mortality rates occurred with Pneumocystis jirovecii pneumonia (21%) and other fungal infections (21%). Lupus nephritis (LN) and endstage renal disease (ESRD) were associated with increased odds of ICU admission (odds ratio [OR] 1.47 [95% CI 1.2-1.8] and OR 2.40 [95% CI 1.7-3.4]) among children admitted for serious infection. ESRD was associated with higher mortality (OR 2.34 [95% CI 1.1-4.9]).

CONCLUSION

Hospitalizations with ICD codes for infection comprised a small proportion of cSLE admissions but accounted for the majority of mortality. The proportion of hospitalizations for infection increased over time. LN and ESRD were risk factors for poor outcomes.

Vaccinations in children with hematologic malignancies and those receiving hematopoietic stem cell transplants or cellular therapies

Children who are immune compromised are uniquely threatened by a higher risk of infections, including vaccine-preventable diseases (VPDs). Children who undergo chemotherapy or cellular therapies may not have preexisting immunity to VPDs at the time of their treatment including not yet receiving their primary vaccine series, and additionally they have higher risk of exposures (e.g., due to family structures, daycare and school setting) with decreased capacity to protect themselves using nonpharmaceutic measures (e.g., masking). In the past, efforts to revaccinate these children have often been delayed or incomplete. Treatment with chemotherapy, stem cell transplants, and/or cellular therapies impair the ability of the immune system to mount a robust vaccine response. Ideally, protection would be provided as soon as both safe and effective, which will vary by vaccine type (e.g., replicating versus nonreplicating; conjugated versus polysaccharide). While a single approach revaccination schedule following these therapies would be convenient for providers, it would not account for patient specific factors that influence the timing of immune reconstitution (IR). Evidence suggests that many of these children would mount a meaningful vaccine response as early as 3 months following completion of treatment. Here within, we provide updated guidance on how to approach vaccination both during and following completion of these therapies.

IL-27 mediates immune response of pneumococcal vaccine SPY1 through Th17 and memory CD4+T cells

Vaccination is an effective means of preventing pneumococcal disease and SPY1 is a live attenuated pneumococcal vaccine we obtained earlier. We found IL-27 and its specific receptor (WSX-1) were increased in SPY1 vaccinated mice. Bacterial clearance and survival rates were decreased in SPY1 vaccinated IL-27Rα-/- mice. The vaccine-induced Th17 cell response and IgA secretion were also suppressed in IL-27Rα-/- mice. STAT3 and NF-κB signaling and expression of the Th17 cell polarization-related cytokines were also decreased in IL-27Rα-/- bone-marrow-derived dendritic cells(BMDC) stimulated with inactivated SPY1. The numbers of memory CD4+T cells were also decreased in SPY1 vaccinated IL-27Rα-/- mice. These results suggested that IL-27 plays a protective role in SPY1 vaccine by promoting Th17 polarization through STAT3 and NF-κB signaling pathways and memory CD4+T cells production in the SPY1 vaccine. In addition, we found that the immune protection of SPY1 vaccine was independent of aerobic glycolysis.

General Practitioners' Awareness and Perception of Current Pneumococcal Vaccination for Adult Patients with Known Risk Factors in Switzerland: Evidence from a Survey

In Switzerland, the National Immunization Advisory Group (NITAG) has formulated recommendations for pneumococcal vaccination among adult risk patients. Little is known about general practitioners' (GPs') perception, knowledge, and implementation of these recommendations. Therefore, we investigated GPs' awareness and drivers of and barriers to pneumococcal vaccination using a cross-sectional web-based survey of GPs. Of the 300 study participants, 81.3% were aware of the recommendations for vaccinating at-risk adult patients, but only 42.7% were aware of all risk groups. The recommendations were perceived by 79.7% as slightly to very complex. Most GPs (66.7%) had good arguments to convince patients to get vaccinated, but only 41.7% reported recognizing patients at risk for pneumococcal disease, and only 46.7% checked their patients' vaccination status and proposed vaccination if needed. The main reasons for not vaccinating were patients' refusal (80.1%), lack of reimbursement by the health insurance (34.5%), patients' fear of side effects (25.1%), and lack of regulatory approval despite the NITAG recommendations (23.7%). Most (77.3%) agreed that the treating chronic disease specialist should recommend the vaccination and 94.7% believed that adult-risk patients would not be aware of their need for pneumococcal vaccinations. Optimal implementation of the recommendations will require addressing knowledge gaps and reported barriers.

Pneumococcal vaccination among adult risk patient with axial spondyloarthritis in Switzerland: Data from the survey of the ankylosing spondylitis association of Switzerland (SVMB)

While in Switzerland, pneumococcal vaccination is recommended for adult patients with axial spondyloarthritis (axSpA) treated with biological drugs, since 2014, little is known about the vaccination status of this specific patient population. This study assessed their vaccination status as part of a larger online survey by the ankylosing spondylitis association of Switzerland (SVMB). Out of 1560 who participated in the survey, 834 (53.5%) were eligible for the analysis. Vaccine coverage was low at 32.5% (271/834). Women and patients who got a flu shot every year were more likely to be covered. Age was negatively associated with being vaccinated. Most (54.2%; 147/271) were vaccinated by their general practitioner. Almost two-thirds of those who had not received the vaccine stated that it had not been offered to them (64.1%; 302/471). In summary, the vaccination coverage is low, but might be increased if the vaccine was offered systematically by general practitioners and specialists.

Low Pneumococcal Vaccination among Patients with Psoriasis in Germany: Results from Vac-Pso

While suboptimal pneumococcal vaccination rates have been reported in immunosuppressed patients with rheumatic diseases, data for patients with psoriasis (PsO) or atopic dermatitis (AD) are scarce. Pneumococcal vaccination in Germany is recommended in patients with certain comorbidities, immunosuppression, and/or aged 60 years or above. The aim of this multicenter cross-sectional study was to investigate the pneumococcal vaccination rate in patients with PsO compared to patients with AD and to evaluate patient perceptions. All patients completed a questionnaire on vaccination status and perceptions, patient and disease characteristics, as well as comorbidity. Medical records and vaccination certificates were reviewed. Over the whole cohort (n = 327 PsO (41.9% female), n = 98 AD (42.9% female)), 83.8% and 42.9% of PsO and AD patients, respectively, had an indication for pneumococcal vaccination due to immunosuppressive treatment. The pneumococcal vaccination rate was 14.4% and 10.2% in PsO and AD patients, respectively. The vaccination rate depended significantly on age, working status and presence of psoriatic arthritis. The most common reason for nonvaccination was lacking recommendation by physicians. Higher awareness, particularly for vaccination indication due to immunosuppression among dermatologists, general physicians, and patients, is warranted.

Altmışbeş Yaş ve Üzeri Erişkinlerde Pnömokok Bağışıklaması ve Ülkemizdeki Pnömokok Aşı Uygulamaları

Sorunu ortaya çıkmadan önlemek şüphesiz tedaviye göre kolay ve ucuz bir yöntemdir. Birinci basamak sağlık hizmetlerinin esasını oluşturan koruyucu sağlık hizmetlerinden aşılama, aşı ile önlenebilir hastalıkların önlenmesi ve bu hastalıklara bağlı kayıpların azaltılabilmesi için olmazsa olmazdır. Yaşlılarda ve yüksek riskli erişkinlerde önemli morbidite ve mortaliteye sebep olan pnömokok infeksiyonlarına karşı ülkemizde uygulanan iki tip aşı vardır: konjuge pnömokok aşısı ve polisakkarid pnömokok aşısı. Erişkinlerde pnömokok aşılarının yararı kanıtlanmış olmasına rağmen aşı uygulanma oranları hedeflenen düzeyde olmadığı için iyileştirme çalışmalarına ihtiyaç vardır. Birinci basamak çalışanları başta olmak üzere aşı uygulayıcılarının eğitilmesi ve farkındalığının artırılması, topluma aşıların yararları ve olası riskleri hakkında yeterli bilgi verilmesi, sağlık kontrollerinin ve kayıtların düzenli olması, aşıların yeterli miktarda ve ücretsiz olarak sağlanması gerekmektedir. Bu derleme erişkinlerde pnömokok aşı uygulamalarında mevcut durumu gözden geçirmek ve aşılama oranlarını arttırmak için yapılması gereken uygulamaları vurgulamak amacıyla yazılmıştır.

Community-acquired pneumonia

Community-acquired pneumonia is not usually considered a high-priority problem by the public, although it is responsible for substantial mortality, with a third of patients dying within 1 year after being discharged from hospital for pneumoniae. Although up to 18% of patients with community-acquired pneumonia who were hospitalised (admitted to hospital and treated there) have at least one risk factor for immunosuppression worldwide, strong evidence on community-acquired pneumonia management in this population is scarce. Several features of clinical management for community-acquired pneumonia should be addressed to reduce mortality, morbidity, and complications related to community-acquired pneumonia in patients who are immunocompetent and patients who are immunocompromised. These features include rapid diagnosis, microbiological investigation, prevention and management of complications (eg, respiratory failure, sepsis, and multiorgan failure), empirical antibiotic therapy in accordance with patient's risk factors and local microbiological epidemiology, individualised antibiotic therapy according to microbiological data, appropriate outcomes for therapeutic switch from parenteral to oral antibiotics, discharge planning, and long-term follow-up. This Seminar offers an updated view on community-acquired pneumonia in adults, with suggestions for clinical and translational research.

Characterization and Specification of a Trivalent Protein-Based Pneumococcal Vaccine Formulation Using an Adjuvant-Free Nanogel Nasal Delivery System

We previously developed a safe and effective nasal vaccine delivery system using a self-assembled nanosized hydrogel (nanogel) made from a cationic cholesteryl pullulan. Here, we generated three pneumococcal surface protein A (PspA) fusion antigens as a universal pneumococcal nasal vaccine and then encapsulated each PspA into a nanogel and mixed the three resulting monovalent formulations into a trivalent nanogel-PspA formulation. First, to characterize the nanogel-PspA formulations, we used native polyacrylamide gel electrophoresis (PAGE) to determine the average number of PspA molecules encapsulated per nanogel molecule. Second, we adopted two methods-a densitometric method based on lithium dodecyl sulfate (LDS)-PAGE and a biologic method involving sandwich enzyme-linked immunosorbent assay (ELISA)-to determine the PspA content in the nanogel formulations. Third, treatment of nanogel-PspA formulations by adding methyl-β-cyclodextrin released each PspA in its native form, as confirmed through circular dichroism (CD) spectroscopy. However, when nanogel-PspA formulations were heat-treated at 80 °C for 16 h, CD spectroscopy showed that each PspA was released in a denatured form. Fourth, we confirmed that the nanogel-PspA formulations were internalized into nasal mucosa effectively and that each PspA was gradually released from the nanogel in epithelial cells in mice. Fifth, LDS-PAGE densitometry and ELISA both indicated that the amount of trivalent PspA was dramatically decreased in the heat-treated nanogel compared with that before heating. When mice were immunized nasally using the heat-treated formulation, the immunologic activity of each PspA was dramatically reduced compared with that of the untreated formulation; in both cases, the immunologic activity correlated well with the content of each PspA as determined by LDS-PAGE densitometry and ELISA. Finally, we confirmed that the trivalent nanogel-PspA formulation induced equivalent titers of PspA-specific serum IgG and mucosal IgA Abs in immunized mice. These results show that the specification methods we developed effectively characterized our nanogel-based trivalent PspA nasal vaccine formulation.

Emergent Pneumonia in Children

In recent decades there have been multiple pathogens, viruses and bacteria, which have emerged as causal agents of pneumonia affecting adults, albeit less frequently, to children. For the purposes of this article we have classified emerging pathogens as follows: True emerging, to pathogens identified for the very first time affecting human population (SARS-CoV-1, SARS-CoV-2, MERS-CoV, avian influenza, and hantavirus); Re-emerging, to known pathogens which circulation was controlled once, but they have reappeared (measles, tuberculosis, antimicrobial resistant bacteria such as CA-MRSA, Mycoplasma pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and new serotypes of post-vaccine pneumococcal); and finally, those that we have called old known with new presentations, including common pathogens that, in particular condition, have changed their form of presentation (rhinovirus, and non-SARS coronavirus). We will review for each of them their epidemiology, forms of presentation, therapy, and prognosis in children compared to the adult with the aim of being able to recognize them to establish appropriate therapy, prognostics, and effective control measures.

Vaccinations and Immune Response in Celiac Disease

Immune response to vaccinations in celiac patients is of growing scientific interest. However, some aspects of the relationship between celiac disease (CD) and vaccines are still unclear. A comprehensive search of published literature using the PubMed database was carried out using the following key terms: "adaptive immunity", "celiac disease", "humoral immune response", "immunization", and "vaccination". To date, there is no evidence showing any causative association between vaccines and CD development. Therefore, vaccinations may be administered according to the modalities and timing of the National Immunization Schedule for each country. The rotavirus vaccine is currently recommended for the general population, and according to some data, it appears to reduce the risk for the development of CD autoimmunity in the early years of life. Regarding the hepatitis B virus, a booster dose of the vaccine is often required due to the low or the lost immune response rate in CD. Furthermore, determination of hepatitis B antibody titers could be useful in newly diagnosed CD subjects regardless of age at diagnosis. Finally, pneumococcal vaccines may be administered in patients with advancing age at diagnosis and concomitant risk factors. Future clinical practice guidelines for vaccination and monitoring programs in celiac patients could be recommended.

Prevalence and pattern of comorbidities in chronic rheumatic and musculoskeletal diseases: the COMORD study

Increased risk of comorbidities has been reported in Rheumatic and Musculoskeletal Diseases (RMD). We aimed to evaluate the prevalence and pattern of comorbidities in RMD patients nationwide, to identify multimorbidity clusters and to evaluate the gap between recommendations and real screening. Cross-sectional, multicentric nationwide study. Prevalence of comorbidities was calculated according to six EULAR axes. Latent Class Analysis identified multimorbidity clusters. Comorbidities' screening was compared to international and local recommendations. In 769 patients (307 RA, 213 OA, 63 SLE, 103 axSpA, and 83 pSA), the most frequent comorbidities were cardiovascular risk factors and diseases (CVRFD) (hypertension 36.5%, hypercholesterolemia 30.7%, obesity 22.7%, smoking 22.1%, diabetes 10.4%, myocardial infarction 6.6%), osteoporosis (20.7%) and depression (18.1%). Three clusters of multimorbidity were identified: OA, RA and axSpA. The most optimal screening was found for CVRF (> = 93%) and osteoporosis (53%). For malignancies, mammograms were the most optimally prescribed (56%) followed by pap smears (32%) and colonoscopy (21%). Optimal influenza and pneumococcus vaccination were found in 22% and 17%, respectively. Comorbidities were prevalent in RMD and followed specific multimorbidity patterns. Optimal screening was adequate for CVRFD but suboptimal for malignant neoplasms, osteoporosis, and vaccination. The current study identified health priorities, serving as a framework for the implementation of future comorbidity management standardized programs, led by the rheumatologist and coordinated by specialized health care professionals.

Invasive pneumococcal diseases in children and adults before and after introduction of the 10-valent pneumococcal conjugate vaccine into the Austrian national immunization program

Background

In February 2012 the ten-valent pneumococcal conjugate vaccine (PCV10) with a 2+1 doses schedule (3, 5, 12 or 14 months of age) without catch-up vaccination was introduced in Austria. We assessed direct and indirect vaccine effects on invasive pneumococcal disease (IPD) by a population-based intervention study.

Methods

The study period was divided into pre- (2009–2011) and post-period (2013–2017, February), regarding 2012 as transition year. Outcomes were defined as PCV10 ST-IPD, the PCV10-related ST 6A and 19A IPD and non-PCV10 excluding ST 6A-/19A-IPD (NVT-IPD). We used national surveillance data and compared average monthly incidence rate (IR) between pre- and post-period among <5, 5–49 and ≥50 years old. Additionally, for the 5–49 and ≥50 years old, and the 50–59 and ≥60 years old, we analyzed monthly incidence data of the pre-, post-period, and estimated trend and level changes by using a segmented time-series regression.

Results

The PCV-10 IPD was reduced by 58% (95% CI: 30%; 74%) and 67% (95% CI: 32%; 84%) among <5 and ≥50 years old; the reduction in ≥60 years was 71% (95% CI: 36%; 88%). There were no significant changes in the pre-post-rate or incidence trend of NVT-IPD in the <5 and ≥50 years old. ST-specific analyses revealed no ST 6A- and ST 19A IPD decline in any age-group, and a ST 8 IPD increase among ≥50 years old (IR ratio: 3.5; 95% CI: 1.7; 7.2). We found no vaccine effects among 5–49 years old.

Conclusions

Our study adds to the evidence on direct and indirect protection of a childhood PCV10 vaccine program. Elderlies seem to benefit the most. Findings did not support PCV 10 cross-protection, but indicate replacement at least for ST 8 among the ≥50 years old. Follow-up analyses of IPD surveillance data are needed to fully characterize the magnitude of serotype replacement and further vaccine-attributable IPD reduction with time.

Characterization of macrolide-resistant non-invasive pneumococci in the pre-vaccine era in Serbia

Numerous reports have confirmed that increased macrolide use in the treatment of respiratory tract infection has contributed to the emergence of antibiotic resistance worldwide. Studies have also shown that pneumococcal vaccine can reduce pneumococcal resistance. The aim of this study was to determine the prevalence of co-resistance to penicillin and other antibiotics in macrolide-resistant (MR) non-invasive pneumococcal isolates and to evaluate serotype distribution in resistant strains in the pre-vaccine era in Serbia. About 80% of MR isolates expressed the MLS phenotype with very high resistance to both erythromycin and clindamycin. A total of 132 (84.1%) MR isolates were multiresistant, i.e., they were resistant to erythromycin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole. Among 157 MR pneumococci, 11 different serotypes were found. Four serotypes, 19F, 14, 6B, and 23F, accounted for 77.7% of all MR pneumococcal isolates. Among isolates with the cMLS phenotype, serotypes 19F and 14 were predominant, whereas serotype 6A was the most common among those with the M phenotype, followed by 14. In conclusion, co-resistance to macrolides and penicillin in our non-invasive pneumococcal isolates is high. The majority of tested strains (∼80%) belonged to the four serotypes (19F, 14, 6B, and 23F) that are included in all conjugate vaccine formulations.

Invasive pneumococcal disease in Northern Alberta, not a Red Queen but a dark horse

BACKGROUND

The consequences of the introduction of various pneumococcal protein conjugate vaccines (PCV) for children and adults is poorly understood.

OBJECTIVE

We undertook a population-based cohort study of invasive pneumococcal disease (IPD) in Northern Alberta (Canada) from 2000 to 2014, years spanning pre-and early PCV (2000-2004) vs PCV-7 (2005-2009) vs PCV-13 (2010-2014) time periods.

DESIGN

We collected clinical, laboratory, and Streptococcus pneumoniae serotype information on all patients from 2000 to 2014. We determined changes in presentation, outcomes, serotypes, and incidence in children and adults across time periods.

SETTING

There were 509 cases of IPD in children, an 80% decrease over time. Rates of empyema (4.0-15.7%, p < 0.001), ICU admission (13.1-20%), and mortality (1.8-8.4%, p < 0.001) increased over time. There were 2417 cases of IPD in adults. Unlike children, incidence of IPD did not change nor did rates of empyema. ICU admissions increased (p = 0.004) and mortality decreased (18.7-16.5%, p = 0.002). The total number of serotypes causing IPD remained stable in children (22 vs 26 vs 20) while they decreased in adults (49 vs 47 vs 42).

CONCLUSIONS AND RELEVANCE

For children, PCV vaccination strategies resulted in decreased overall rates of IPD and we observed increased rates of empyema and mortality; for adults, there was no change in IPD rates although disease severity increased while mortality decreased. On a population-wide basis, our results suggest that current PCV vaccination strategies are associated with an overall decrease in IPD but disease severity seems to be increasing in both children and adults.

Protective Regulatory T Cell Immune Response Induced by Intranasal Immunization With the Live-Attenuated Pneumococcal Vaccine SPY1 via the Transforming Growth Factor-β1-Smad2/3 Pathway

Vaccine effectiveness is mainly determined by the mechanism mediating protection, emphasizing the importance of unraveling the protective mechanism for novel pneumococcal vaccine development. We previously demonstrated that the regulatory T cell (Treg) immune response has a protective effect against pneumococcal infection elicited by the live-attenuated pneumococcal vaccine SPY1. However, the mechanism underlying this protective effect remains unclear. In this study, a short synthetic peptide (P17) was used to downregulate Tregs during immunization and subsequent challenges in a mouse model. In immunized mice, increase in immune cytokines (IL-12p70, IL-4, IL-5, and IL-17A) induced by SPY1 were further upregulated by P17 treatment, whereas the decrease in the infection-associated inflammatory cytokine TNF-α by SPY1 was reversed. P17 also inhibited the increase in the immunosuppressive cytokine IL-10 and inflammatory mediator IL-6 in immunized mice. More severe pulmonary injuries and more dramatic inflammatory responses with worse survival in P17-treated immunized mice indicated the indispensable role of the Treg immune response in protection against pneumococcal infection by maintaining a balance among acquired immune responses stimulated by SPY1. Further studies revealed that the significant elevation of active transforming growth factor β (TGF-β)1 by SPY1 vaccination activated FOXP3, leading to increased frequencies of CD4⁺CD25⁺Foxp3⁺ T cells. Moreover, SPY1 vaccination elevated the levels of Smad2/3 and phosphor-Smad2/3 and downregulated the negative regulatory factor Smad7 in a time-dependent manner during pneumococcal infection, and these changes were reversed by P17 treatment. These results illustrate that SPY1-stimulated TGF-β1 induced the generation of SPY1-specific Tregs via the Smad2/3 signaling pathway. In addition, SPY1-specific Tregs may participate in protection via the enhanced expression of PD-1 and CTLA-4. The data presented here extend our understanding of how the SPY1-induced acquired Treg immune response contributes to protection elicited by live-attenuated vaccines and may be helpful for the evaluation of live vaccines and other mucosal vaccine candidates.

Cationic pullulan nanogel as a safe and effective nasal vaccine delivery system for respiratory infectious diseases

The mucosal surfaces of the respiratory and gastrointestinal tracts are continuously exposed to countless beneficial and pathologic antigens. These mucosal surfaces are thus equipped with an immune system that is unique from those elsewhere in the body; this unique system provides the first line of immune surveillance and defense against pathogen invasion. The sophisticated immune induction machinery in the aero–digestive tract involves mucosa-associated lymphoid tissues, including nasopharyngeal- and gut-associated lymphoid tissues, for the generation of antigen-specific humoral and cellular immune responses. Consequently, nasal or oral immunization with an appropriate vaccine delivery vehicle prompts the induction of protective immunity in both the mucosal and systemic compartments, leading to a double layer of protection against pathogens. To harness the benefits of mucosal vaccines, various mucosal antigen delivery vehicles are under development, and a cationic cholesteryl-group-bearing pullulan nanogel (cCHP nanogel) has emerged as a potent nasal vaccine delivery system for the induction of protective immunity against respiratory infections.

Evaluating clinical effectiveness of 13-valent pneumococcal conjugate vaccination against pneumonia among middle-aged and older adults in Catalonia: results from the EPIVAC cohort study

Background

Benefits using the 13-valent pneumococcal conjugate vaccine (PCV13) in adults are controversial. This study investigated clinical effectiveness of PCV13 vaccination in preventing hospitalisation from pneumonia among middle-aged and older adults.

Methods

Population-based cohort study involving 2,025,730 individuals ≥50 years in Catalonia, Spain, who were prospectively followed from 01/01/2015 to 31/12/2015. Primary outcomes were hospitalisation for pneumococcal or all-cause pneumonia and death from any cause. Cox regression models were used to evaluate the association between PCV13 vaccination and the risk of each outcome, adjusting for age, sex and major comorbidities/underlying risk conditions.

Results

Cohort members were observed for a total of 1,990,701 person-years, of which 6912 person-years were PCV13 vaccinated. Overall, crude incidence rates (per 100,000 person-years) were 82.8 (95% confidence interval [CI]: 77.7–88.1) for pneumococcal pneumonia, 637.9 (95% CI: 599.0–678.7) for all-cause pneumonia and 2367.2 (95% CI: 2222.8–2518.7) for all-cause death. After multivariable adjustments we found that the PCV13 vaccination did not alter significantly the risk of pneumococcal pneumonia (multivariable-adjusted hazard ratio [mHR]: 1.17; 95% CI: 0.75–1.83; p = 0.493) and all-cause death (mHR: 1.07; 95% CI: 0.97–1.18; p = 0.190), although it remained significantly associated with an increased risk of all-cause pneumonia (mHR: 1.69; 95% CI: 1.48–1.94; p < 0.001). In stratified analyses focused on middle-aged or elderly persons and immunocompromised or immunocompetent subjects, PCV13 vaccination did not appear effective either.

Conclusion

Our data does not support clinical benefits of PCV13 vaccination against pneumonia among adults in Catalonia. It must be closely monitored in future studies involving more vaccinated person-time at-observation.

Treatment and prevention of invasive pneumococcal disease

Invasive pneumococcal disease is a severe infection that mainly affects patients with associated comorbidity. The paediatric conjugate vaccination has resulted in a change in the adult vaccination strategy. The antibiotic resistance of pneumococcus is not currently a severe problem. Nevertheless, the World Health Organisation has included pneumococcus among the bacteria whose treatment requires the introduction of new drugs, such as ceftaroline and ceftobiprole. Although the scientific evidence is still limited, the combination of beta-lactams and macrolides is recommended as empiric therapy for bacteraemic pneumococcal pneumonia.

Effect of Age on the Manifestations and Outcomes of Invasive Pneumococcal Disease in Adults

BACKGROUND

Although a considerable amount is known about the effect of age on the manifestations and outcomes of pneumonia, the same is not true for invasive pneumococcal disease.

METHODS

This was a prospective observational study of all cases (2435) of invasive pneumococcal disease in adults in Northern Alberta from 2000 to 2014. Rates of invasive pneumococcal disease per 100,000, sociodemographic variables, clinical characteristics, and invasive pneumococcal disease-related outcomes were compared for the following age groups: 17-54, 55-64, 65-74, and ≥75 years.

RESULTS

The rate of invasive pneumococcal disease per 100,000 increased with increasing age. Although only 27.3% of the cases were in those aged ≥65 years, they accounted for 48% of the deaths. The case fatality rate increased with increasing age, from 9.6% for those aged 17-54 years to 31.7% for those aged ≥75 years. The rate of meningitis decreased with increasing age, as did admission to intensive care and use of mechanical ventilation. There was a marked reduction in the rate of invasive pneumococcal disease due to protein conjugate vaccine 7 and protein conjugate vaccine 13 serotypes in those aged ≥55 years but a much smaller decline in rates for those aged 17-54 years. Replacement with non-vaccine serotypes constituted approximately 50% of the cases.

CONCLUSIONS

The rate of invasive pneumococcal disease is highest in the very elderly, and manifestations of invasive pneumococcal disease are influenced by age.

Necrotizing pneumonia: an emerging problem in children?

BACKGROUND

In children, necrotizing pneumonia (NP) is an uncommon, severe complication of pneumonia. It is characterized by destruction of the underlying lung parenchyma resulting in multiple small, thin-walled cavities and is often accompanied by empyema and bronchopleural fistulae.

REVIEW

NP in children was first reported in children in 1994, and since then there has been a gradual increase in cases, which is partially explained by greater physician awareness and use of contrast computed tomography (CT) scans, and by temporal changes in circulating respiratory pathogens and antibiotic prescribing. The most common pathogens detected in children with NP are pneumococci and Staphylococcus aureus. The underlying disease mechanisms are poorly understood, but likely relate to multiple host susceptibility and bacterial virulence factors, with viral-bacterial interactions also possibly having a role. Most cases are in previously healthy young children who, despite adequate antibiotic therapy for bacterial pneumonia, remain febrile and unwell. Many also have evidence of pleural effusion, empyema, or pyopneumothorax, which has undergone drainage or surgical intervention without clinical improvement. The diagnosis is generally made by chest imaging, with CT scans being the most sensitive, showing loss of normal pulmonary architecture, decreased parenchymal enhancement and multiple thin-walled cavities. Blood culture and culture and molecular testing of pleural fluid provide a microbiologic diagnosis in as many as 50% of cases. Prolonged antibiotics, draining pleural fluid and gas that causes mass effects, and maintaining ventilation, circulation, nutrition, fluid, and electrolyte balance are critical components of therapy. Despite its serious nature, death is uncommon, with good clinical, radiographic and functional recovery achieved in the 5-6 months following diagnosis. Increased knowledge of NP's pathogenesis will assist more rapid diagnosis and improve treatment and, ultimately, prevention.

CONCLUSION

It is important to consider that our understanding of NP is limited to individual case reports or small case series, and treatment data from randomized-controlled trials are lacking. Furthermore, case series are retrospective and usually confined to single centers. Consequently, these studies may not be representative of patients in other locations, especially when allowing for temporal changes in pathogen behaviour and differences in immunization schedules and antibiotic prescribing practices.

Strategies to develop vaccines of pediatric interest

INTRODUCTION

The success of the vaccines available on the market has significantly increased interest in vaccine development. Areas covered: The main aim of this paper is to discuss the most important vaccines of pediatric interest that are currently being developed. New pneumococcal vaccines and vaccines against group B Streptococcus, Staphylococcus aureus and respiratory syncytial virus are analyzed in detail. Expert commentary: Advances in understanding human immunology, including human monoclonal antibody identification, sequencing technology, and the ability to solve atomic level structures of vaccine targets have provided tools to guide the rational design of future vaccines. It is likely that some of these vaccines will reach the market in the future and will thus partially contribute to the prevention of very severe diseases that significantly affect the morbidity and mortality of children. However, further studies in animals and several clinical trials in children must be performed before new vaccines become licensed.

Epidemiology, virulence factors and management of the pneumococcus

Pneumococcal infections continue to cause significant morbidity and mortality in patients throughout the world. This microorganism remains the most common bacterial cause of community-acquired pneumonia and is associated with a considerable burden of disease and health-care costs in both developed and developing countries. Emerging antibiotic resistance has been a concern because of its potential negative impact on the outcome of patients who receive standard antibiotic therapy. However, there have been substantial changes in the epidemiology of this pathogen in recent years, not least of which has been due to the use of pneumococcal conjugate vaccines in children, with subsequent herd protection in unvaccinated adults and children. Furthermore, much recent research has led to a better understanding of the virulence factors of this pathogen and their role in the pathogenesis of severe pneumococcal disease, including the cardiac complications, as well as the potential role of adjunctive therapy in the management of severely ill cases. This review will describe recent advances in our understanding of the epidemiology, virulence factors, and management of pneumococcal community-acquired pneumonia.

ADVICE for a healthier life: Adult Vaccination Campaign in Europe

Immunization is one of the most effective public health measures to prevent disease. Despite relatively good vaccination rates in childhood in many parts of the world, vaccines to prevent diseases are underused in the adult population and adult vaccination rates are still far below the target. The European Federation of Internal Medicine (EFIM), declared that 'internal medicine must focus on better care for individuals, better health care for populations and lower costs'. Adult vaccination is a good example of a public health initiative aimed at reducing morbidity and mortality, but awareness of the need for adult vaccination and uptake of the programs across Europe is variable. The Adult Vaccination Campaign in Europe (ADVICE) was developed with an aim to raise awareness for adult vaccination and to understand the dynamics of the vaccination practices and the possible barriers against achieving targeted vaccination rates in Europe. In order to reach vaccination targets, we need evidence based, up to date guidelines; recommendations at national and international levels; surveillance for vaccination rates; and opportunities to provide vaccines more readily. Leadership at a European level and a firm research and action agenda are crucial. The European Federation of Internal Medicine can take the lead as it declared its interest on 'better care for individuals, better health care for populations'. Hence, we consider ADVICE a very timely and very valuable initiative to draw a roadmap to improve adult vaccination rates in Europe.