Effectiveness of 23-valent pneumococcal polysaccharide vaccine on diabetic elderly

Expert panel opinion on adult pneumococcal vaccination in the post-COVID era (NAP- EXPO Recommendations-2024)

INTRODUCTION

Pneumococcal diseases pose a significant public health concern in India, with substantial morbidity and mortality, with the elderly and those with coexisting medical conditions being most at risk. Pneumococcus was also seen to be one of the main reasons for co-infection, pneumonia and complications in COVID. Current guidelines recommend vaccination for specific adult populations, but there is a lack of uniformity and guidance on risk stratification, prioritisation and optimal timing.

METHODS

Nation Against Pneumococcal Infections - Expert Panel Opinion (NAP-EXPO) is a panel convened to review and update recommendations for adult pneumococcal vaccination in India. The panel of 23 experts from various medical specialties engaged in discussions and evidence-based reviews, discussed appropriate age for vaccination, risk stratification for COPD and asthma patients, vaccination strategies for post-COVID patients, smokers and diabetics, as well as methods to improve vaccine awareness and uptake.

OUTCOME

The NAP-EXPO recommends the following for adults: All healthy individuals 60 years of age and above should receive the pneumococcal vaccine; all COPD patients, regardless of severity, high-risk asthma patients, post-COVID cases with lung fibrosis or significant lung damage, should be vaccinated with the pneumococcal vaccine; all current smokers and passive smokers should be educated and offered the pneumococcal vaccine, regardless of their age or health condition; all diabetic individuals should receive the pneumococcal vaccine, irrespective of their diabetes control. Strategies to improve vaccine awareness and uptake should involve general practitioners (GPs), primary health physicians (PHPs) and physicians treating patients at high risk of pneumococcal disease. Advocacy campaigns should involve media, including social media platforms.

CONCLUSION

These recommendations aim to enhance pneumococcal vaccination coverage among high-risk populations in India in order to ensure a reduction in the burden of pneumococcal diseases, in the post-COVID era. There is a need to create more evidence and data to support the recommendations that the vaccine will be useful to a wider range of populations, as suggested in our consensus.

Diabetes as a risk factor for pneumococcal disease and severe related outcomes and efficacy/effectiveness of vaccination in diabetic population. Results from meta-analysis of observational studies

AIMS

To collect all available evidence on the effect of diabetes mellitus (DM) as a risk factor for pneumococcal disease incidence and related complications, and on the efficacy/effectiveness of vaccines in patients with DM.

METHODS

Two distinct systematic searches on MEDLINE, Cochrane, ClinicalTrials.gov and EMBASE databases were performed, one for each meta-analysis, collecting all observational (cohort and case-control) studies and randomized clinical trials performed on humans up to June 1st, 2023.

RESULTS

We retrieved 36 observational studies comparing risk for pneumococcal disease and related complications in people with or without DM, and 11 studies (1 randomized clinical trial and 10 observational studies) assessing conjugated and polysaccaridic vaccines efficacy/effectiveness on preventing such outcomes. People with DM were at higher risk for Invasive Pneumococcal Disease (unadjusted OR 2.42 [2.00; 2.92]); Case-Fatality Rate (unadjusted OR 1.61 [1.25; 2.07], Pneumococcal pneumonia (unadjusted OR 2.98 [2.76; 3.22), and Intensive care unit admission for pneumococcal disease (unadjusted OR 2.09 [1.20; 3.66]). In diabetic individuals vaccinated with conjugated vaccine, incidence of pneumonia specific for vaccine type in a clinical trial (OR 0.237 [0.008; 0.704]), and hospitalization for overall pneumonia during the year following the polysaccharide vaccination in observational studies (unadjusted OR 0.63 [0.45-0.89]) were significantly lower in comparison with unvaccinated DM subjects, with no significant differences for other outcomes.

CONCLUSIONS

People with diabetes mellitus are at higher risk for less favourable course of pneumococcal disease and should be therefore targeted in vaccination campaigns; more evidence needs to be collected on vaccination outcomes in people with diabetes.

Adherence to Advisory Committee on Immunization Practices in diabetes mellitus patients in Saudi Arabia: A multicenter retrospective study

BACKGROUND

Patients with diabetes mellitus (DM) are predisposed to an increased risk of infection signifying the importance of vaccination to protect against its potentially severe complications. The Centers for Disease Control and Prevention/Advisory Committee on Immunization Practices (CDC/ACIP) issued immunization re-commendations to protect this patient population.

AIM

To assess the adherence of patients with DM to the CDC/ACIP immunization recommendations in Saudi Arabia and to identify the factors associated with the vaccine adherence rate.

METHODS

An observational retrospective study conducted in 2023 was used to collect data on the vaccination records from 13 diabetes care centers in Saudi Arabia with 1000 eligible patients in phase I with data collected through chart review and 709 patients in phase II through online survey.

RESULTS

Among participants, 10.01% (n = 71) had never received any vaccine, while 85.89% (n = 609) received at least one dose of the coronavirus disease 2019 (COVID-19) vaccine, and 34.83% (n = 247) had received the annual influenza vaccine. Only 2.96% (n = 21), 2.11% (n = 15), and 1.12% (n = 8) received herpes zoster, tetanus, diphtheria, and pertussis (Tdap), and human papillomavirus (HPV) vaccines, respectively. For patients with DM in Saudi Arabia, the rate of vaccination for annual influenza and COVID-19 vaccines was higher compared to other vaccinations such as herpes zoster, Tdap, pneumococcal, and HPV. Factors such as vaccine recommendations provided by family physicians or specialists, site of care, income level, DM-related hospitalization history, residency site, hemoglobin A1c (HbA1c) level, and health sector type can significantly influence the vaccination rate in patients with DM. Among non-vaccinated patients with DM, the most reported barriers were lack of knowledge and fear of side effects. This signifies the need for large-scale research in this area to identify additional factors that might facilitate adherence to CDC/ACIP vaccine recommendations in patients with DM.

CONCLUSION

In Saudi Arabia, patients with DM showed higher vaccination rates for annual influenza and COVID-19 vaccines compared to other vaccinations such as herpes zoster, Tdap, pneumococcal, and HPV. Factors such as vaccine recommendations provided by family physicians or specialists, the site of care, income level, DM-related hospitalization history, residency site, HbA1c level, and health sector type can significantly influence the vaccination rate in patients with DM.

Effectiveness of pneumococcal vaccination on hospitalization and death in the adult and older adult diabetic population: a systematic review

INTRODUCTION

Diabetic patients are at a higher risk of getting pneumococcal disease and are therefore recommended to get vaccinated. The aim of our systematic review is the retrieval and analysis of all available evidence on the effect of pneumococcal vaccination on the risk of hospitalization and death in adult patients with diabetes.

RESEARCH DESIGN AND METHODS

MEDLINEand EMBASE were searched from inception until January 2023. We included all studies investigating whether pneumococcal vaccination reduces the risk of dying or being hospitalized in diabetic patients. The Newcastle-Ottawa scale was used to assess risk of bias.

RESULTS

Only two studies, encompassing a total of 68,246 subjects, were considered eligible for inclusion and of high quality. In both studies polysaccharide pneumococcal vaccination was associated with a reduction of the risk of hospitalization or death in adult diabetic patients (aHR: 0.76 in one study, aOR: 0.97 in the other one). However, in neither of the two included studies the lower risk was statistically significant.

CONCLUSIONS

Further research is needed due to the potentially major clinical implications for diabetic patients. The results of this systematic review can serve as a foundation for future studies, indicating the importance of continuing research in this area to improve patient outcomes.

Risk of community acquired pneumonia in patients with diabetes mellitus: Review

The article for the first time provides a relatively comprehensive overview of the main aspects of the epidemiology and clinical features of infectious pathology, i.e., community-acquired pneumonia, as comorbid and aggravating conditions in patients with type 1 and type 2 diabetes mellitus. Risk factors and pathogenetic patterns of infectious processes development, as well as the special etiological role of pneumococcal infection in this group of patients, are considered. Particular attention is paid to the possibilities of and approaches to the primary prevention of vaccine-preventable infections as the causes of the development of community-acquired pneumonia and invasive diseases in patients with diabetes mellitus with a review of international studies, guidelines, and local experience data in pneumococcal infection immunization.

Systematic literature review of the disease burden and vaccination of pneumococcal disease among adults in select Asia-Pacific areas

INTRODUCTION

Pneumococcal diseases are common and cause significant morbidity and mortality, with higher rates especially in developing areas including many in the Asia-Pacific (AP) region. However, current strategies to prevent pneumococcal disease in adults are quite complicated and not well implemented among many AP areas, and vaccination coverage rates among adults are generally low or perceived as low in the region. Thus, this literature review's purpose was to summarize the disease burden and vaccination against pneumococcal diseases among adults in select AP areas (Australia, Hong Kong, India, Indonesia, South Korea, Malaysia, New Zealand, the Philippines, Singapore, Taiwan, Thailand, and Vietnam).

AREAS COVERED

This systematic review included published articles from January 2010 to August 2020 using MEDLINE/Embase. Grey literature websites were searched for national immunization programs and medical society vaccination recommendations from areas of interest. A total of 69 publications were identified.

EXPERT OPINION

In the AP region, pneumococcal disease burden and serotype prevalence are variable among adult populations, particularly among older adults. Data was provided primarily from countries with established national immunization programs (NIPs). Further research on the disease burden and emphasis on the benefits of vaccination in AP areas lacking pneumococcal vaccination programs is warranted.

Machine-Learning Techniques for Feature Selection and Prediction of Mortality in Elderly CABG Patients

Coronary artery bypass surgery grafting (CABG) is a commonly efficient treatment for coronary artery disease patients. Even if we know the underlying disease, and advancing age is related to survival, there is no research using the one year before surgery and operation-associated factors as predicting elements. This research used different machine-learning methods to select the features and predict older adults' survival (more than 65 years old). This nationwide population-based cohort study used the National Health Insurance Research Database (NHIRD), the largest and most complete dataset in Taiwan. We extracted the data of older patients who had received their first CABG surgery criteria between January 2008 and December 2009 (n = 3728), and we used five different machine-learning methods to select the features and predict survival rates. The results show that, without variable selection, XGBoost had the best predictive ability. Upon selecting XGBoost and adding the CHA2DS score, acute pancreatitis, and acute kidney failure for further predictive analysis, MARS had the best prediction performance, and it only needed 10 variables. This study's advantages are that it is innovative and useful for clinical decision making, and machine learning could achieve better prediction with fewer variables. If we could predict patients' survival risk before a CABG operation, early prevention and disease management would be possible.

COVID-19 vaccination in patients with diabetes mellitus: Current concepts, uncertainties and challenges

BACKGROUND AND AIMS

To summarize the available evidence on the use COVID-19 vaccines in patients with diabetes mellitus.

METHODS

We performed a thorough literature search with regard to COVID-19 vaccines in patients with type 1 and type 2 diabetes mellitus.

RESULTS

The novel coronavirus disease (COVID-19) tends to portend a poor prognosis in patients with diabetes mellitus (DM). Primary prevention remains the mainstay for mitigating the risks associated with COVID-19 in patients with DM. A significant step in primary prevention is timely vaccination. Routine vaccination against pneumococcal pneumonia, influenza, and hepatitis B is recommended in patients with DM with good efficacy and reasonable safety profile. With clinical data supporting a robust neutralizing antibody response in COVID-19 patients with DM, vaccination in individuals with DM is justified. In fact, as the burden of the disease is borne by people with DM, COVID-19 vaccination should be prioritized in individuals with DM. Multiple unresolved issues with regard to preferred vaccine type, vaccine efficacy and durability, frequency of administration, vaccination in children (<18 years) and pregnant/lactating women however remain, and need to be addressed through future research.

CONCLUSIONS

Patients with type 1 and type 2 diabetes mellitus are at a high risk of poor prognosis with COVID-19 and vaccination should be prioritized in them. However, many unresolved issues with regard to COVID-19 vaccination need to be addressed through future research.

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

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

The Pneumococcal Polysaccharide-Tetanus Toxin Native C-Fragment Conjugate Vaccine: The Carrier Effect and Immunogenicity

The encapsulated bacteria, as Streptococcus pneumonia, Haemophilus influenzae type b, and Neisseria meningitidis, cause serious morbidity and mortality worldwide. The capsular polysaccharide (PS), which could elicit a weak T cell-independent immune response, is a vital virulence determinant. One of the strategies to improve the PS-specific immunogenicity is to conjugate PS with a nontoxic carrier protein. Tetanus toxoid (TT) and CRM₁₉₇ are the typical carrier proteins for the PS conjugate vaccines. TT is the inactivated tetanus toxin manipulated with formaldehyde, which suffers from the pollution from residual formaldehyde and the incomplete detoxification. CRM₁₉₇ has the disadvantage of low-yield purification with the requirement of sophisticated culture conditions. Thus, a novel carrier protein without these disadvantages is highly required. The tetanus toxin native C-fragment (Hc) is safe, low-cost, and highly immunogenic with easy purification, which can act as a promising carrier protein. Pneumococcal serogroups 14 and 23F were major epidemic causes of pneumococcal infections. In the present study, the capsular PSs (PS14 and PS23F) were conjugated with Hc, TT, and CRM₁₉₇, respectively. TT- and CRM₁₉₇-based conjugates acted as controls for Hc-based conjugates (PS14-Hc and PS23F-Hc). The structural properties of Hc were not fundamentally changed after conjugated with PS. PS14-Hc and PS23F-Hc could potentiate sound PS-specific antibody levels comparable to the controls. Thus, Hc exhibited a practical carrier effect to help the pneumococcal conjugate vaccines perform good immunogenicities.

The phenyl linker markedly increases the immunogenicity of the pneumococcal polysaccharide conjugate vaccine

OBJECTIVE

Capsular polysaccharide (PS) of Streptococcus pneumoniae is a key virulence factor and typically conjugated with a carrier protein. It is necessary to improve the immunogenicity of the conjugate vaccine against S. pneumoniae.

RESULTS

A phenyl linker between tetanus toxoid (TT) and S. pneumoniae Type 14 PS was used to improve the PS-specific immunogenicity of the conjugate vaccine. As compared with the one with the amyl linker (PS-TT), the conjugate with the phenyl linker (PS-phe-TT) decreased the TT-specific IgG titers and significantly increased the PS-specific IgG titers and the IL-5 level.

CONCLUSION

The phenyl linker could potentiate a robust humoral immune response to PS by decreasing the carrier-induced epitopic suppression effect. PS-phe-TT was expected to act as an effective vaccine against S. pneumoniae.