Risk of pneumococcal diseases in adults with underlying medical conditions: a retrospective, cohort study using two Japanese healthcare databases

Validity of claims-based definition of number of remaining teeth in Japan: Results from the Longevity Improvement and Fair Evidence Study

BACKGROUND

Secondary healthcare data use has been increasing in the dental research field. The validity of the number of remaining teeth assessed from Japanese dental claims data has been reported in several studies, but has not been tested in the general population in Japan.

OBJECTIVES

To evaluate the validity of the number of remaining teeth assessed from Japanese dental claims data and assess its predictability against subsequent health deterioration.

METHODS

We used the claims data of residents of a municipality that implemented oral health screening programs. Using the number of teeth in the screening records as the reference standard, we assessed the validity of the claims-based number of teeth by calculating the mean differences. In addition, we assessed the association between the claims-based number of teeth and pneumococcal disease (PD) or Alzheimer's disease (AD) in adults aged ≥65 years using Cox proportional hazards analyses.

RESULTS

Of the 10,154 participants, the mean number of teeth assessed from the claims data was 20.9, that in the screening records was 20.5, and their mean difference was 0.5. During the 3-year follow-up, PD or AD onset was observed in 10.4% (3,212/30,838) and 5.3% (1,589/30,207) of participants, respectively. Compared with participants with ≥20 teeth, those with 1-9 teeth had a 1.29 (95% confidence interval [CI]: 1.17-1.43) or 1.19 (95% CI: 1.04-1.36) times higher risk of developing PD or AD, respectively.

CONCLUSION

High validity of the claims-based number of teeth was observed. In addition, the claims-based number of teeth was associated with the risk of PD and AD.

Vaccine Responses in Patients with Liver Cirrhosis: From the Immune System to the Gut Microbiota

Vaccines prevent a significant number of deaths annually. However, certain populations do not respond adequately to vaccination due to impaired immune systems. Cirrhosis, a condition marked by a profound disruption of immunity, impairs the normal immunization process. Critical vaccines for cirrhotic patients, such as the hepatitis A virus (HAV), hepatitis B virus (HBV), influenza, pneumococcal, and coronavirus disease 19 (COVID-19), often elicit suboptimal responses in these individuals. The humoral response, essential for immunization, is less effective in cirrhosis due to a decline in B memory cells and an increase in plasma blasts, which interfere with the creation of a long-lasting response to antigen vaccination. Additionally, some T cell subtypes exhibit reduced activation in cirrhosis. Nonetheless, the persistence of memory T cell activity, while not preventing infections, may help to attenuate the severity of diseases in these patients. Alongside that, the impairment of innate immunity, particularly in dendritic cells (DCs), prevents the normal priming of adaptive immunity, interrupting the immunization process at its onset. Furthermore, cirrhosis disrupts the gut-liver axis balance, causing dysbiosis, reduced production of short-chain fatty acids (SCFAs), increased intestinal permeability, and bacterial translocation. Undermining the physiological activity of the immune system, these alterations could impact the vaccine response. Enhancing the understanding of the molecular and cellular factors contributing to impaired vaccination responses in cirrhotic patients is crucial for improving vaccine efficacy in this population and developing better prevention strategies.

Advancements in Vaccine Strategies for Chronic Liver Disease Patients: Navigating Post-COVID Challenges and Opportunities

This review addresses the vital role of vaccinations in managing patients with chronic liver disease (CLD), especially in the context of the post-COVID-19 landscape. The pandemic has highlighted the unique vulnerabilities of CLD patients, including those awaiting liver transplantation and post-transplant individuals, who face heightened risks of infection due to compromised immune responses. Recent advancements in vaccine technology, such as mRNA platforms, novel adjuvants, and advanced delivery systems, have significantly accelerated vaccine development, enhancing both speed and efficacy. Moreover, the emergence of personalized vaccines, tailored to everyone's unique immunological profile, presents new opportunities, particularly for those with chronic conditions. This review synthesizes the current state of evidence regarding vaccine recommendations for CLD patients, focusing on their response to vaccinations and proposing effective strategies to protect this vulnerable group from vaccine-preventable diseases. It also explores the challenges in implementing these strategies and considers the impact of emerging vaccine delivery systems on improving outcomes for CLD patients. The paper aims to provide nuanced guidance on vaccination in the rapidly evolving healthcare landscape, addressing both technological innovations and comprehensive patient care strategies.

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

BACKGROUND

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Societal Cost of Racial Pneumococcal Disease Disparities in US Adults Aged 50 Years or Older

OBJECTIVE

This study aimed to estimate the societal cost of racial disparities in pneumococcal disease among US adults aged ≥  50 years.

METHODS

In a model-based analysis, societal costs of invasive pneumococcal disease (IPD) and hospitalized nonbacteremic pneumococcal pneumonia (NBP) were estimated using (1) direct medical costs plus indirect costs of acute illness; (2) indirect costs of pneumococcal mortality; and (3) direct and indirect costs of related disability. Disparities costs were calculated as differences in average per-person pneumococcal disease cost between Black and non-Black adults aged ≥  50 years multiplied by the Black population aged ≥  50 years. Costs were in 2019 US dollars (US$), with future costs discounted at 3% per year.

RESULTS

Total direct and indirect costs per IPD case were US$186,791 in Black populations and US$182,689 in non-Black populations; total hospitalized NBP costs per case were US$100,632 (Black) and US$96,781 (non-Black). The difference in population per-person total pneumococcal disease costs between Black and non-Black adults was US$47.85. Combined societal costs of disparities for IPD and hospitalized NBP totaled US$673.2 million for Black adults aged ≥  50 years. Disease and disability risks, life expectancy, and case-fatality rates were influential in one-way sensitivity analyses, but the lowest cost across all analyses was US$194 million. The 95% probability range of racial disparity costs were US$227.2-US$1156.9 million in a probabilistic sensitivity analysis.

CONCLUSIONS

US societal cost of racial pneumococcal disease disparities in persons aged ≥ 50 years is substantial. Successful pneumococcal vaccination policy and programmatic interventions to mitigate these disparities could decrease costs and improve health.

Vaccination in liver diseases and liver Transplantation: Recommendations, implications and opportunities in the post-covid era

The interest in vaccination efficacy and toxicity has surged following the Covid-19 pandemic. Immune responses to several vaccines have been shown to be suboptimal in patients with chronic liver disease (CLD) or post-liver transplant (LT), as a consequence of cirrhosis-associated immune dysfunction (CAID) or post-LT immunosuppression respectively. Accordingly, vaccine-preventable infections may be more common or severe than in the general population. The Covid-19 pandemic has greatly accelerated research and development into vaccination technology and platforms, which will have spillover benefits for liver patients. The aims of this review are: (i) to discuss the impact of vaccine-preventable infections on CLD and post-LT patients, (ii) to appraise current evidence supporting vaccination strategies, and (iii) to provide some insight into recent developments relevant for liver patients.

Recent advancement, immune responses, and mechanism of action of various vaccines against intracellular bacterial infections

Emerging and re-emerging bacterial infections are a serious threat to human and animal health. Extracellular bacteria are free-living, while facultative intracellular bacteria replicate inside eukaryotic host cells. Many serious human illnesses are now known to be caused by intracellular bacteria such as Salmonella enterica, Escherichia coli, Staphylococcus aureus, Rickettsia massiliae, Chlamydia species, Brucella abortus, Mycobacterium tuberculosis and Listeria monocytogenes, which result in substantial morbidity and mortality. Pathogens like Mycobacterium, Brucella, MRSA, Shigella, Listeria, and Salmonella can infiltrate and persist in mammalian host cells, particularly macrophages, where they proliferate and establish a repository, resulting in chronic and recurrent infections. The current treatment for these bacteria involves the application of narrow-spectrum antibiotics. FDA-approved vaccines against obligate intracellular bacterial infections are lacking. The development of vaccines against intracellular pathogenic bacteria are more difficult because host defense against these bacteria requires the activation of the cell-mediated pathway of the immune system, such as CD8+ T and CD4+ T. However, different types of vaccines, including live, attenuated, subunit, killed whole cell, nano-based and DNA vaccines are currently in clinical trials. Substantial development has been made in various vaccine strategies against intracellular pathogenic bacteria. This review focuses on the mechanism of intracellular bacterial infection, host immune response, and recent advancements in vaccine development strategies against various obligate intracellular bacterial infections.

Clinical Characteristics, Antimicrobial Resistance, and Outcomes of Patients with Invasive Pneumococcal Disease in Ningxia Hui Autonomous Region, China, 2013-2021

Objectives

This study aimed to analyze the clinical features, antibiotic susceptibility profiles, and outcomes of patients with invasive pneumococcal disease (IPD) at a hospital in Ningxia Hui Autonomous Region, to provide the basis for improving the clinical treatment effect.

Methods

Patients with IPD were retrospectively collected from 2013 to 2021. Clinical manifestations, laboratory tests, antimicrobial susceptibility, antibiotic treatment, and outcomes of the disease were analyzed.

Results

In this study, we identified 127 IPD cases, of whom 49 (38.6%) had meningitis and 78 (61.4%) had bacteremia. The median ages of pediatric cases and adult cases were 2 years (IQR: 0-5) and 52.5 years (IQR: 35-62), respectively. There were 27 and 45 males in the pediatric and adult groups, and no significant gender difference in the different age groups (p = 0.584) was found. Of 75 cases with underlying diseases, pneumonia (11%), malignancy (11%), hypertension (9.4%), and hepatic cirrhosis (7.9%) were the most common. The incidence of underlying diseases was even higher in the adult group (67.1%) than in the pediatric group (47.1%) (p = 0.028). The frequency of fever, cough, and seizures was significantly higher in the pediatric group than in the adult group, with p-values of 0.004, 0.004, and 0.001, respectively. The percentage of neutrophils in the blood was significantly higher in the adult cases than in the pediatric cases (p  <  0.001). Furthermore, there was a significantly higher WBC count (p  <  0.001), percentage of neutrophils (p = 0.012), and protein level (p = 0.019) in the CSF samples in the adult patients compared to pediatric patients. The susceptibility rates of S. pneumoniae isolates to vancomycin, linezolid, and levofloxacin were 100%. The susceptibility rates of penicillin were 98.7% and 34.1% in bacteremia and meningitis patients, respectively. Most isolates were resistant to erythromycin, clindamycin, tetracycline, and azithromycin. The most common antibiotic treatment was β-lactams. Seven (5.5%) patients died during hospitalization, and 38 (29.9%) patients' health deteriorated.

Conclusion

These results may provide a reference basis for the diagnosis and empiric treatment of IPD in the region.

Impact of maternal depression and anxiety-related disorders on live birth rate in women with recurrent pregnancy loss

It is unknown whether depression and anxiety-related conditions associate with poor perinatal outcomes, especially live birth rates, among women diagnosed with recurrent pregnancy loss. We performed a retrospective cohort study using the Japanese Medical Data Centre Claims Database and identified women diagnosed with recurrent pregnancy loss. Live birth rates were compared as the primary outcome between patients with and without depression and/or anxiety-related disorders. A stabilised inverse probability of treatment weight analysis using propensity scores was also performed to assess the association. Among 5,517 eligible patients, there were 804 (14.6%) women who had depression and/or anxiety-related disorders during treatment for recurrent pregnancy loss during pregnancy. The overall live birth rates differed significantly between the groups according to the Kaplan-Meier method and log-rank test (p = 0.011). However, Cox proportional-hazards regression model and stabilised inverse probability of treatment weight analysis showed no statistically significant association between depressive disorders and live birth rates. The current study showed that approximately 15% of patients diagnosed with recurrent pregnancy loss develop depressive disorders. After accounting for variables, we found no independent association between depressive disorders after recurrent pregnancy losses and low live birth rates.

Risk of cardiovascular events leading to hospitalisation after Streptococcus pneumoniae infection: a retrospective cohort LIFE Study

OBJECTIVES

To elucidate the risk of cardiovascular event occurrence following Streptococcus pneumoniae infection.

DESIGN

Retrospective cohort study using a LIFE Study database.

SETTING

Three municipalities in Japan.

PARTICIPANTS

Municipality residents who were enrolled in either National Health Insurance or the Latter-Stage Elderly Healthcare System from April 2014 to March 2020.

EXPOSURE

Occurrence of S. pneumoniae infection.

PRIMARY OUTCOME MEASURES

Occurrence of one of the following cardiovascular events that led to hospitalisation after S. pneumoniae infection: (1) coronary heart disease (CHD), (2) heart failure (HF), (3) stroke or (4) atrial fibrillation (AF).

RESULTS

S. pneumoniae-infected patients were matched with non-infected patients for each cardiovascular event. We matched 209 infected patients and 43 499 non-infected patients for CHD, 179 infected patients and 44 148 non-infected patients for HF, 221 infected patients and 44 768 non-infected patients for stroke, and 241 infected patients and 39 568 non-infected patients for AF. During follow-up, the incidence rates for the matched infected and non-infected patients were, respectively, 38.6 (95% CI 19.9 to 67.3) and 30.4 (29.1 to 31.8) per 1000 person-years for CHD; 69.6 (41.9 to 108.8) and 50.5 (48.9 to 52.2) per 1000 person-years for HF; 75.4 (48.3 to 112.2) and 35.5 (34.1 to 36.9) per 1000 person-years for stroke; and 34.7 (17.9 to 60.6) and 11.2 (10.4 to 12.0) per 1000 person-years for AF. Infected patients were significantly more likely to develop stroke (adjusted HR: 2.05, 95% CI 1.22 to 3.47; adjusted subdistribution HR: 1.94, 95% CI 1.15 to 3.26) and AF (3.29, 1.49 to 7.26; 2.74, 1.24 to 6.05) than their non-infected counterparts.

CONCLUSIONS

S. pneumoniae infections elevate the risk of subsequent stroke and AF occurrence. These findings indicate that pneumococcal infections have short-term effects on patients' health and increase their midterm to long-term susceptibility to serious cardiovascular events.

Real-world evaluation of osteoporotic fractures using the Japan Medical Data Vision database

In Japanese patients who experienced an osteoporotic fracture, 10.8% and 18.6% had a subsequent fracture within 1 and 2 years of follow-up, respectively. Although the burden of hip and vertebral fractures has been reported widely, we found that patients with non-hip non-vertebral (NHNV) fractures had a 26% higher risk of subsequent fracture than patients with hip fractures; therefore, NHNV fractures should also be considered an important risk factor for subsequent fracture.

INTRODUCTION

To investigate imminent risk and odds of subsequent osteoporotic fractures and associated risk factors in patients who experienced an initial osteoporotic fracture.

METHODS

Patients aged ≥ 50 years with ≥ 1 osteoporotic fracture were analyzed from Japan's Medical Data Vision (MDV) database of claims from acute-care hospitals (January 2012-January 2017). Multivariable models were constructed to explore the impact of key comorbidities and medications on the subsequent fracture risk: Cox proportional hazards model for time to subsequent fracture and logistic regression models for odds of subsequent fracture within 1 and 2 years from index fracture.

RESULTS

In total, 32,926 patients were eligible with a median follow-up duration of 12.3 months. The percentage of patients experiencing subsequent fractures was 14.1% across the study duration, and 10.8% and 18.6% in patients with 1 and 2 years of follow-up, respectively. In the Cox proportional hazards model, patients with vertebral or NHNV index fractures had a higher subsequent fracture risk than patients with a hip index fracture (adjusted hazard ratio [aHR] 1.11 and 1.26, respectively); subsequent fracture risk was lower in males than females (aHR 0.89). Patients with baseline claims for tranquilizers and glucocorticoids had a higher subsequent fracture risk than those without (aHR 1.14 and 1.08, respectively). Additionally, baseline claims for anti-Parkinson's medications, alcoholism, and stage 4/5 chronic kidney disease were significantly associated with higher odds of subsequent fracture in the logistic regression models.

CONCLUSION

Several clinical and demographic factors were associated with a higher risk and odds of subsequent fracture. This may help to identify patients who should be prioritized for osteoporosis treatment.

Pneumococcal and influenza vaccination coverage among at-risk adults: A 5-year French national observational study

INTRODUCTION

The risk of developing pneumococcal infections increases with certain chronic conditions and in immunocompromised patients. We aimed to monitor pneumococcal vaccination coverage in at-risk patients and to examine factors associated with pneumococcal vaccination in France.

MATERIAL AND METHODS

In this annual cross-sectional study, at-risk patients were extracted between 2014 and 2018 from the National Health Insurance's (NHI) General scheme's claims database with their vaccine reimbursements. Descriptive analyses and a logistic model were performed to assess the influence of healthcare use and medical and demographic factors on pneumococcal vaccination.

RESULTS AND DISCUSSION

In 2018, 4.5% of 4,045,021 at-risk adults were up to date with their pneumococcal vaccination. During the study period, the number of patients with chronic medical conditions (86% of 4,045,021) increased by 10.1%, but vaccination coverage decreased from 12.9% to 2.9%. The population with immunocompromised status (14% of 4,045,021) increased by 16.2% and vaccination coverage from 10.3% to 18.8%. Influenza vaccination coverage was much higher and stable (around 45.0%). Factors associated with pneumococcal vaccination were: immunocompromised status vs. having a chronic medical condition (odds ratio [OR] 4.72), influenza vaccination (OR 2.36-3.42), hepatitis B vaccination (OR 2.82), DTPolio vaccination (OR 1.52), ≥5 specialist physicians' visits (OR 1.17), and age above 74 (OR 1.12). Pneumococcal vaccine dispensing was extremely low (median of 9per GP,1per specialist over 9 years) despite frequent healthcare visits.

CONCLUSION

Pneumococcal and influenza vaccination coverage of adults at risk of pneumococcal disease fell well below public health expectations. Invitations for pneumococcal vaccination should be sent by the NHI to high-risk patients. Patient management protocols should include pneumococcal vaccination. Patients with multiple comorbidities are a high-priority population given the large potential health gains offered by pneumococcal vaccination. Commitment of both scientific societies and health authorities is urgently needed to increase vaccination coverage in at-risk populations.

Risk factors for pneumococcal disease in persons with chronic medical conditions: Results from the LIFE Study

OBJECTIVES

This study aimed to identify the risk factors for pneumococcal disease.

METHODS

The study was performed using insurance claims data from the residents of 12 Japanese municipalities. Based on recorded diagnoses, we identified chronic medical conditions in each patient between April 2015 and March 2016 and examined the subsequent occurrence of a pneumococcal disease from April 2016 onward. Cox proportional hazards models were used to estimate the hazard ratio of each chronic medical condition for a pneumococcal disease occurrence.

RESULTS

The study was conducted on 732,235 patients, of whom, 61,306 (8.4%) were aged 0-18 years, 184,367 (25.2%) were aged 19-49 years, 126,078 (17.2%) were aged 50-64 years, and 360,484 (49.2%) were aged ≥65 years. A higher number of conditions was associated with a higher incidence of pneumococcal disease. Significant risk factors for pneumococcal disease in all patients included chronic heart disease, chronic lung disease, diabetes mellitus, cancer, and chronic renal disease. Furthermore, chronic lung disease, diabetes mellitus, aspiration pneumonia, and immunosuppressant use were risk factors among patients aged 50-64 years.

CONCLUSIONS

Persons aged 50-64 years with multiple chronic medical conditions or with specific conditions are at a higher risk of developing pneumococcal disease, indicating a need to consider their inclusion in routine vaccination programs.

Promising Expectations for Pneumococcal Vaccination during COVID-19

The emergence of new viral infections has increased over the decades. The novel virus is one such pathogen liable for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, popularly known as coronavirus disease 2019 (COVID-19). Most fatalities during the past century's influenza pandemics have cooperated with bacterial co/secondary infections. Unfortunately, many reports have claimed that bacterial co-infection is also predominant in COVID-19 patients (COVID-19 associated co/secondary infection prevalence is up to 45.0%). In the COVID-19 pandemic, Streptococcus pneumoniae is the most common coinfecting pathogen. Half of the COVID-19 mortality cases showed co-infection, and pneumonia-related COVID-19 mortality in patients >65 years was 23%. The weakening of immune function caused by COVID-19 remains a high-risk factor for pneumococcal disease. Pneumococcal disease and COVID-19 also have similar risk factors. For example, underlying medical conditions on COVID-19 and pneumococcal diseases increase the risk for severe illness at any age; COVID-19 is now considered a primary risk factor for pneumococcal pneumonia and invasive pneumococcal disease. Thus, pneumococcal vaccination during the COVID-19 pandemic has become more critical than ever. This review presents positive studies of pneumococcal vaccination in patients with COVID-19 and other medical conditions and the correlational effects of pneumococcal disease with COVID-19 to prevent morbidity and mortality from co/secondary infections and superinfections. It also reports the importance and role of pneumococcal vaccination during the current COVID-19 pandemic era to strengthen the global health system.

A phase 3, multicenter, single-arm, open-label study to assess the safety, tolerability, and immunogenicity of a single dose of 13-valent pneumococcal conjugate vaccine in Japanese participants aged 6-64 years who are considered to be at increased risk of pneumococcal disease and who are naive to pneumococcal vaccines

BACKGROUND

This open-label, single-arm, phase 3 study evaluated safety and immunogenicity of the 13-valent pneumococcal conjugate vaccine (PCV13) in pneumococcal vaccine-naive Japanese individuals aged 6-64 years at increased risk of pneumococcal disease (PD).

METHODS

Participants received 1 PCV13 dose. Reactogenicity events were recorded for 7 days (individuals aged 6- to 17-year-old) or 14 days (individuals aged 18 to 64 years old) postvaccination. Adverse events (AEs) were collected for 1 month postvaccination. Opsonophagocytic activity (OPA) and anticapsular immunoglobulin G (IgG) geometric mean concentrations (GMCs) were measured for vaccine serotypes before and 1 month postvaccination. Post hoc analyses compared immunogenicity in participants categorized as at-risk (immunocompetent but having chronic medical conditions associated with increased PD risk) or high-risk (immunocompromised due to diseases/conditions and/or medications).

RESULTS

206 participants aged 6- to 17-year-old (n = 53) and 18 to 64 years old (n = 153) completed the study. Reactogenicity events were generally mild to moderate in severity. AEs were reported in 16% (33/206) of participants; 1.0% (2/206) were severe. Six AEs were vaccine-related; most were associated with local reactions. No serious AEs occurred. Circulating antibody levels for all 13 serotypes increased postvaccination. OPA geometric mean fold rises (GMFRs) from prevaccination to 1 month postvaccination were 5.5-61.7; lower limits of the 2-sided, 95% CI were > 1 for all serotypes. IgG GMFRs were consistent with OPA analyses. In post hoc analyses, 55.8% (115/206) and 44.2% (91/206) of participants were categorized as at risk and at high risk of PD, respectively; OPA GMFRs from prevaccination to 1 month postvaccination were 3.9-635.1, with lower limits of the 2-sided 95% CIs > 1 for all 13 serotypes across these risk groups; IgG GMFRs were consistent with OPA analyses.

CONCLUSIONS

PCV13 was well tolerated and immunogenic in Japanese individuals aged 6-64 years considered at increased risk of PD. Results were broadly comparable with past PCV13 studies in other Japanese and non-Japanese populations. Registration number: NCT03571607; JapicCTI-184024.

Prophylactic vaccine delivery systems against epidemic infectious diseases

Prophylactic vaccines have evolved from traditional whole-cell vaccines to safer subunit vaccines. However, subunit vaccines still face problems, such as poor immunogenicity and low efficiency, while traditional adjuvants are usually unable to meet specific response needs. Advanced delivery vectors are important to overcome these barriers; they have favorable safety and effectiveness, tunable properties, precise location, and immunomodulatory capabilities. Nevertheless, there has been no systematic summary of the delivery systems to cover a wide range of infectious pathogens. We herein summarized and compared the delivery systems for major or epidemic infectious diseases caused by bacteria, viruses, fungi, and parasites. We also included the newly licensed vaccines (e.g., COVID-19 vaccines) and those close to licensure. Furthermore, we highlighted advanced delivery systems with high efficiency, cross-protection, or long-term protection against epidemic pathogens, and we put forward prospects and thoughts on the development of future prophylactic vaccines.

Adults at risk of pneumococcal disease in France

BACKGROUND

Immunocompromised patients and those with certain underlying medical conditions are at risk of pneumococcal disease, but in France their vaccine coverage is largely unknown. We aimed to assess the number of adult patients eligible for pneumococcal vaccination in France.

METHODS

We conducted an annual cross-sectional study based on retrospective data from the French National Health Data System. Over 2014-2018, we included all adults continuously affiliated to the General health insurance scheme (covering 76% of the population), at risk of pneumococcal disease. Patients were identified with published or newly developed algorithms using diagnoses and reimbursements for hospital stays, medical procedures, and specific treatments, laboratory tests, or medical devices.

RESULTS

On January 1, 2018, we identified 4,045,021 at-risk patients (11% increase since 2014). Mean age was 66.1years (55.1% were aged≥65), 51% were men, and 18% had at least two conditions. Of these, 3,634,594 had a chronic medical condition (including 2,617,921 patients treated for diabetes, 616,003 for chronic respiratory disease, 424,223 for heart failure, and 285,214 for chronic liver disease) and 570,035 were immunocompromised (of these, 191,527 were treated with immunosuppressive drugs or biotherapy, 152,255 with chemotherapy for cancer, and 100,604 for HIV).

CONCLUSION

These published or newly developed algorithms - which can be used to address other public health issues - identified more than 4 million adults eligible for pneumococcal vaccination in the main health insurance scheme (10% of the studied adult population). This is a first step towards ensuring patients get vaccinated as part of their chronic condition management.

Cost-effectiveness analysis for PCV13 in adults 60 years and over with underlying medical conditions which put them at an elevated risk of pneumococcal disease in Japan

Background: The objective of this study was to conduct a cost-effectiveness analysis of PCV13 vs. PPV23 and no vaccination and PPV23 vs. no vaccination in adults aged ≥ 60 years with underlying medical conditions which put them at an elevated risk of pneumococcal disease in a Japanese healthcare setting.Research design and methods: A natural history model was developed with a life-long time horizon and 1-year cycle length, with microsimulation as a modeling technique. The expected costs from a public payer's and societal perspective, quality-adjusted life-years (QALYs), and prevented cases and deaths caused by IPD (invasive pneumococcal disease) and NBP (non-bacteremic pneumococcal pneumonia) were estimated.Results: In the base-case scenario, the cost per QALY gained from a public payer's perspective for PCV13 vs, PPV23 and no vaccination were 500,255JPY and 1,139,438JPY, respectively, The cost per QALY gained for PPV23 vs no vaccination was 1,687,057JPY. Over the life-long time horizon for 1 million patients, when compared to PPV23, PCV13 resulted in 65 fewer IPD cases, 2,894 fewer NBP cases, and 384 fewer deaths caused by pneumococcal disease.Conclusions: In adults aged 60 years and over with underlying medical conditions, PCV13 was shown to be a more cost-effective alternative to PPV23.

Multiple comorbidities increase the risk of death from invasive pneumococcal disease under the age of 65 years

INTRODUCTION

Risk factors for death from invasive pneumococcal disease (IPD) have not been clearly established in patients aged under 65 years. We aimed to evaluate contributions of host and bacterial factors to the risk of death from IPD in patients aged under 65 years in Japan.

METHODS

In this prospective, observational, multicenter cohort study, patients with IPD (n = 581) aged 6-64 years were enrolled between 2010 and 2017. We investigated the role of host and bacterial factors in 28-day mortality.

RESULTS

The mortality rate increased from 3.4% to 6.2% in patients aged 6-44 years to 15.5%-19.5% in those aged 45-64 years. Multivariable analysis identified the following risk factors for mortality: age 45-64 years (hazard ratio [HR], 3.4; 95% confidence interval [CI], 1.6-6.8, p = 0.001), bacteremia with unknown focus (HR, 2.0; 95% CI, 1.1-3.7, p = 0.024), meningitis (HR, 2.1; 95% CI, 1.1-4.0, p = 0.019), underlying multiple non-immunocompromising conditions (HR, 2.6; 95% CI, 1.1-7.4, p = 0.023), and immunocompromising conditions related to malignancy (HR, 2.4; 95% CI, 1.0-5.2, p = 0.039). Pneumococcal serotype was not associated with poor outcomes.

CONCLUSIONS

Host factors, including age of 45-64 years and underlying multiple non-immunocompromising conditions, are important for the prognosis of IPD. Our results will contribute to the development of targeted pneumococcal vaccination strategies in Japan.

Changes in the Penetration Rate of Biosimilar Infliximab Within Japan Using a Japanese Claims Database

Purpose

Infliximab, which was approved in 2002, had its first biosimilar launched in 2014 across Japan. However, the penetration rate of this biosimilar remains unclear given the limited data regarding its current clinical use throughout Japan. This study was conducted to describe the current clinical characteristics of patients receiving infliximab and the penetration rate of the reference infliximab and/or biosimilar infliximab using a Japanese administrative claims database.

Patients and Methods

This retrospective, descriptive study utilized the Japan Medical Data Vision database, a nationwide hospital-based database. Data on patients receiving infliximab recorded from April 2008 to March 2019 were extracted from the database. Patient characteristics of the reference and biosimilar infliximab groups and penetration rates according to fiscal year, target diseases diagnosis, and subsidy for intractable diseases were examined.

Results

A total of 9735 patients were extracted for analysis, among whom 92% (n=8950) and 8% (n=785) received only reference infliximab and its biosimilar, respectively. Both groups exhibited similar clinical characteristics. The biosimilar penetration rate increased from 0.8% in 2014 to 22.5% in 2018, with overall penetration rates throughout the period according to diagnosis (with or without subsidy) being 14.4% (with, 4.1%; without, 16.4%), 4.7% (with, 3.7%; without, 10.6%), 5.7% (with, 4.5%; without, 13.5%), and 7.5% (with, 4.4%; without, 8.2%) for rheumatoid arthritis, Crohn’s disease, ulcerative colitis, and psoriasis, respectively.

Conclusion

Biosimilar infliximab is prescribed for patients with similar characteristics to reference infliximab. Despite the increasing penetration rates according to target disease, they remain much lower among patients receiving subsidy for intractable disease than among those who do not.

Effect of Japanese herbal Kampo medicines on live birth rate in women with recurrent pregnancy loss

OBJECTIVE

To determine the effectiveness of Japanese Kampo medicines on the overall live birth rate among patients with recurrent pregnancy loss (RPL) in a real-world setting.

METHODS

In the current retrospective cohort study, we used the JMDC Claims Database to extract information on women diagnosed with RPL between January 1, 2005 and August 31, 2018. Eligible women were divided into two groups according to Kampo medicines administered as treatments for RPL. The primary outcome was the live birth rate during the study period. Propensity score matching, Kaplan-Meier cumulative incidence plots, log-rank test, and Cox proportional-hazards regression model were used to compare the primary outcome between patients with and without Japanese herbal Kampo medicines.

RESULTS

Among 5517 eligible patients, 1652 used Kampo medicines and 3865 did not. After propensity score matching, the live birth rate at 2.0 years was 15.7% in the Kampo group and 11.2% in the non-Kampo group. At 4.0 years, the difference between the two groups had slightly increased. The overall live birth rate differed significantly between the two groups (hazard ratio 1.32, 95% confidence interval 1.13-1.53; P < 0.001).

CONCLUSION

Japanese herbal Kampo medicines may improve the live birth rate in patients with RPL.

Pneumococcal vaccine coverage among individuals aged 18 to 64 years old with underlying medical conditions in the UK: a retrospective database analysis

BACKGROUND

In the UK certain groups with pre-disposing conditions are eligible for vaccination with the pneumococcal polysaccharide vaccine (PPV23). Uptake of the vaccine in these individuals has not been reported for 10 years. Hence this study investigated the rates of pneumococcal vaccination, the time to vaccination since diagnosis, and factors associated with vaccination in individuals aged 18-64 years with certain underlying medical conditions.

METHODS

A retrospective database analysis was conducted using the Clinical Practice Research Datalink (CPRD). Individuals aged 18 to 64 years who had a diagnosis for underlying medical conditions of interest at the index date (January 1, 2011 to December 31, 2015) were included in this study. Both underlying conditions and pneumococcal vaccination were identified using Read codes. A multivariable logistic regression model was used to identify factors associated with pneumococcal vaccination.

RESULTS

A total of 99,153 individuals with underlying medical conditions were included in this study. Within 1 year of follow-up, 13.6% had received pneumococcal vaccination. This figure rose to 32.0% after 4 years of follow-up. The mean time between diagnosis and vaccination was 148.7 days across the overall cohort. Based on multivariate analysis of results, individuals with chronic heart disease, chronic kidney disease, chronic liver disease, chronic respiratory disease or diabetes mellitus were significantly less likely (P < 0.0001) to be vaccinated than those with immunosuppression. Individuals were significantly more likely to receive a pneumococcal vaccination if they received an influenza vaccination in the first year of follow-up than those who did not (P < 0.001).

CONCLUSIONS

Despite the Joint Committee on Vaccination and Immunisation (JCVI) recommendations for pneumococcal vaccination in clinical risk groups, rates of pneumococcal vaccination are suboptimal in the UK for individuals aged 18-64 with underlying medical conditions. Further emphasis should be made on the importance of increased pneumococcal vaccination coverage in the UK, given the increased risk of morbidity and mortality associated with indicative underlying medical conditions.

Serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae associated with invasive pneumococcal disease among adults in Japan

OBJECTIVES

This study evaluated the serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae isolates from adults (aged ≥20 years) with invasive pneumococcal disease (IPD) in Japan.

METHODS

This prospective observational study was conducted in 49 participating Japanese hospitals. S. pneumoniae isolates were serotyped and tested for antimicrobial susceptibility at a central laboratory. Information regarding patient characteristics, underlying disease, IPD clinical syndromes, and treatment was collected through medical chart review.

RESULTS

The final analysis included 177 patients enrolled from 45 hospitals between September 2016 and April 2018 (bacteraemic pneumonia, 110; bacteraemia without identified focus, 29; meningitis, 19). Most patients (70.1%) were aged ≥65 years and most had underlying disease (79.1%). The proportion of isolates from serotypes contained in the pneumococcal polysaccharide vaccine (PPV) 23 was 61.0%, while those in the pneumococcal conjugate vaccine (PCV) 7 and PCV13 were 2.8% and 28.2%, respectively. Non-vaccine serotypes accounted for 37.9% of all isolates and 50.8% of isolates from immunosuppressed patients. Serotype 12F was the most common vaccine serotype, followed by serotype 3.

CONCLUSIONS

The continued disease burden of IPD in adults in Japan warrants improved vaccination rates and development of next-generation vaccines that include serotypes not currently covered.

CLINICAL TRIAL REGISTRATION

Clinical trial summary registration number 160,822,918,146; JapicCTI-163352.

Epidemiology, vaccine effectiveness, and risk factors for mortality for pneumococcal disease among hospitalised adults in Singapore: a case-control study

BACKGROUND

Streptococcus pneumoniae infections can lead to severe morbidity and mortality, especially in patients with invasive pneumococcal disease (IPD). This study evaluated factors associated with pneumococcal disease, pneumococcal vaccine effectiveness, and risk factors for all-cause mortality in hospitalised adults with pneumococcal disease in Singapore.

METHODS

Retrospective case-control study of patients tested for pneumococcal disease with streptococcal urinary antigen testing and at least one sterile site culture, during their admission to a tertiary hospital in Singapore from 2015 to 2017. Patients were defined as cases of IPD or non-IPD, or as controls, based on laboratory results and clinical diagnoses. Multivariable models were constructed to determine factors associated with IPD/non-IPD, and risk factors for mortality from pneumococcal disease. Vaccine effectiveness against IPD/non-IPD was estimated using a variation of the test-negative design.

RESULTS

We identified 496 pneumococcal disease cases, of whom 92 (18.5%) had IPD. The mean age of cases was 69.1 ± 15.4 years, and 65.5% were male. Compared with controls (N = 9181), IPD patients were younger (mean age 61.5 ± 16.3 years, vs 72.2 ± 16.1 years in controls; p < 0.001) and with less co-morbidities [median Charlson's score 1 (IQR 0-4), vs 3 (1-5) in controls; p < 0.001]. IPD patients also had the highest proportions with intensive care unit (ICU) admission (20.7%), inpatient mortality (26.1%) and longest median length of stay [9 (IQR 8-17) days]. On multivariable analysis, IPD was negatively associated with prior pneumococcal vaccination (adjusted relative risk ratio = 0.20, 95%CI 0.06-0.69; p = 0.011). Risk factors for mortality among pneumococcal disease patients were ICU admission, diagnosis of IPD, age ≥ 85 years and Charlson's score > 3.

CONCLUSION

Patients with pneumococcal disease (especially IPD) were younger and had less co-morbidities than controls, but had higher risk of severe clinical outcomes and mortality. Pneumococcal vaccination effectiveness against IPD was estimated to be about 80%, and should be encouraged among high-risk patients.

Recent advances in the epidemiology and prevention of Streptococcus pneumoniae infections

The introduction of pneumococcal conjugate vaccines (PCVs) 7 and 13 into national childhood immunization programs in the US in 2000 and 2010, respectively, proved to be remarkably successful in reducing infant mortality due to invasive pneumococcal disease (IPD), resulting in widespread uptake of these vaccines. Secondary herd protection of non-vaccinated adults against IPD has proven to be an additional public health benefit of childhood immunization with PCVs, particularly in the case of the vulnerable elderly who are at increased risk due to immunosenescence and underlying comorbidity. Despite these advances in pneumococcal immunization, the global burden of pneumococcal disease, albeit of unequal geographic distribution, remains high. Reasons for this include restricted access of children living in many developing countries to PCVs, the emergence of infection due to non-vaccine serotypes of the pneumococcus, and non-encapsulated strains of the pathogen. Emerging concerns affecting the elderly include the realization that herd protection conferred by the current generation of PCVs (PCV7, PCV10, and PCV13) has reached a ceiling in many countries at a time of global population aging, compounded by uncertainty surrounding those immunization strategies that induce optimum immunogenicity and protection against IPD in the elderly. All of the aforementioned issues, together with a consideration of pipeline and pending strategies to improve access to, and serotype coverage of, PCVs, are the focus areas of this review.

A Japanese nationwide survey of 23-valent pneumococcal capsular polysaccharide vaccine (PPSV23) coverage among patients with chronic medical condition aged 50 and older

The 23-valent capsular polysaccharide pneumococcal vaccine (PPSV23) was introduced in Japan’s routine immunization schedule October 2014. It was recommended for adults aged 65 years (including those ≥65 during the transition period), and for adults 60–64 with cardiac, renal, or respiratory dysfunction equivalent to Level 1 physical disability. Several studies have shown that patients aged 50+ with chronic medical conditions (CMC) are at elevated risk of pneumococcal infection. Nonetheless, PPSV23 vaccination rates among this population remains low. In our study, we report the results of a survey investigation into PPSV23 vaccination rates among Japanese patients aged 50+ with CMC. Patients aged 50+ comprised the patient population (n = 5,078) and internal medicine physicians comprised the doctor population (n = 400) located all over Japan were asked an array of questions relevant to PPSV23 immunization in June 2018 via Web-based surveys. PPSV23 coverages among chronic patients aged 50–59, 60–64, and 65+ years were respectively 1.3%, 2.9%, and 37.8%. The high disease-specific PPSV23 rates seen in the 65+ group was 50.0% and 49.4%, for chronic liver disease and chronic lung disease, respectively. Doctors most frequently cited a lack of municipal subsidies as justification for recommending the vaccine to patients with CMC aged 50–64 years, and deference to patients’ wishes as justification for patients with CMC aged 65+. In conclusion, PPSV23 has poor coverage among Japanese adults aged 50–64 with CMC. Doctors and local authorities need to raise public awareness to improve the vaccination rate, given the high risk of pneumococcal infectious disease among patients with CMC.