Pneumococcal Vaccine Research Articles

Patients with immune mediated inflammatory diseases are insufficiently protected against vaccine-preventable infections.

Patients with Immune Mediated Inflammatory Diseases (IMIDs) using immunosuppressive therapy are at increased risk of infections, including vaccine-preventable infections. In this study, we aimed to evaluate whether patients with IMIDs on systemic immunosuppressive therapy are vaccinated according to current guidelines. A survey was sent out, between August 2022 and March 2023, to all patients with IMIDs that visited the departments of dermatology, rheumatology and gastroenterology at an academic and regional hospital in Rotterdam, the Netherlands. Patient-reported vaccination status was compared to the Dutch guidelines on vaccinations in patients with chronic inflammatory diseases. A total of 1,905/5,987 patients responded to the survey (response rate 32%). After exclusion of patients without systemic immunosuppressive medication, the study population comprised 1,390 patients, median age 56 years (IQR 42-66) and 41% male. Most patients (92%) had been vaccinated according to the Dutch National Immunization Program. Before starting immunosuppressive therapy, 2% of the patients who were still considered at risk according to the Dutch guideline were vaccinated for measles, and 4% for diphtheria/tetanus/polio (DT-IPV). Additionally, 62% of patients received an annual influenza vaccine, 16% received a five-yearly pneumococcal vaccine, and 91% were fully vaccinated against COVID-19. Patients with IMIDs on immunosuppressive therapy are not vaccinated in accordance with the guidelines. Implementation strategies to improve the vaccination rates for patients with IMIDs should specifically focus on vaccinating against measles and diphtheria/tetanus/polio, and periodic vaccination against pneumococcal and influenza infections.

Immunogenicity and safety of different combinations involving a third booster dose of SARS-CoV-2 inactivated vaccine, inactivated quadrivalent influenza vaccine, and 23-valent pneumococcal polysaccharide vaccine in adults aged ≥60 years: a phase 4, randomized, open-label study.

Concomitant administration of COVID-19, influenza, and pneumococcal vaccines could reduce the burden on healthcare systems. However, the immunogenicity and safety of various combinations of a third booster dose of SARS-CoV-2 inactivated vaccine (CoronaVac), inactivated quadrivalent influenza vaccine (IIV4), and 23-valent pneumococcal polysaccharide vaccine (PPV23), particularly in different age groups, is still unknown. A phase 4, randomized, open-label, controlled trial was conducted in Beijing, China. 636 healthy adults were divided into two age groups (18-59 and ≥60 years) and randomized equally into three groups: CoronaVac and IIV4 followed by PPV23; CoronaVac and PPV23 followed by IIV4; or CoronaVac followed by IIV4 and PPV23, with a 28-day interval between vaccinations. Immunogenicity was evaluated by measuring antibody titers, and safety was monitored. ClinicalTrials.gov Identifier: NCT05298800. Co-administration of a third dose of CoronaVac, IIV4, and PPV23 in any combination was safe. Among adults aged 18-59, co-administration with PPV23 maintained non-inferiority of antibody levels for CoronaVac and IIV4, despite a slight reduction in antibody responses. This reduction was not observed in participants ≥60 years. Furthermore, co-administration of IIV4 and PPV23 affected seroconversion rates for both vaccines. Co-administration of the third dose of SARS-CoV-2 inactivated vaccine with the influenza vaccine, followed by PPV23, may be optimal for adults aged 18-59. In adults ≥60, all vaccine combinations were immunogenic, suggesting a flexible vaccination approach. Since antibody measurements were taken 28 days post-vaccination, ongoing surveillance is essential to assess the longevity of the immune responses.

Pneumococcal carriage and changes in serotype distribution post- PCV13 introduction in children in Matiari, Pakistan

BackgroundIn early 2021, the 10-valent Pneumococcal conjugate vaccine (PCV10) was replaced with 13-valent (PCV13) by the federal directorate of immunization (FDI), Pakistan. We assessed the impact of a higher valent vaccine, PCV13, on the serotype distribution of nasopharyngeal carriage in rural Pakistan. MethodsChildren <2 years were randomly selected from two rural union councils of Matiari, Sindh in Pakistan between September–October,2022. Clinical, sociodemographic and vaccination histories were recorded. Nasopharyngeal swabs were collected and processed at Infectious Disease Research Laboratory, Aga Khan University, Karachi. Whole genome sequencing was performed on the culture positive isolates. ResultsOf the 200 children enrolled, pneumococcus was detected in 140(70 %) isolates. Majority of age-eligible children (60.1 %,110/183) received 3 PCV13 doses. PCV10 carriage declined from 13.2 %(78/590) in 2017/18 to 7.2 % (10/140) in 2022, additional PCV13 serotypes (3, 6A/6C and 19A) decreased from 18.5 %(109/590) to 11.4 %(16/140) while non-PCV13 serotypes increased from 68.3 %(403/590) to 81.4 %(114/140). There were 88.5 %(n = 124), 80.7 %(n = 113), 55.0 %(n = 77), and 46.0 %(n = 65) isolates predicted to be resistant to cotrimoxazole, penicillin(meningitis cut-off), tetracycline, and erythromycin respectively. ConclusionReplacing PCV10 with PCV13 rapidly decreased prevalence of PCV13 carriage among vaccinated children in Matiari, Pakistan. Vaccine-driven selection pressure may have been responsible for the increase of non-PCV13 serotypes.

Multicentre case–control study of pneumococcal infections among children with pneumonia in Peninsular Malaysia (MY-Pneumo): a study protocol

BackgroundS. pneumoniae (SPN) is the most common cause of pneumonia. The disease can be effectively prevented through immunisation. Since December 2020, the Malaysian Government has included the 10-valent pneumococcal conjugate vaccine (PCV10) for all infants born on or after 1 January 2020 as part of the National Immunisation Programme (NIP). However, the epidemiology of pneumonia remains poorly understood. To fill the knowledge gap, we established a multicentre surveillance study to understand the burden of pneumococcal pneumonia among young children in Peninsular Malaysia.MethodsMY-Pneumo is a multicentre prospective case–control study conducted in three sentinel sites located in three different states of Peninsular Malaysia – Kuala Lumpur, Pahang, and Kelantan. A cohort of at least 500 incident cases and 500 controls is enrolled beginning in October 2021 and matched for age. Cases are hospitalised children < 5 years with radiologically confirmed pneumonia, and the controls are children without any features suggestive of pneumonia. Clinical samples, including nasopharyngeal swabs (NPS) and urine, are collected according to the study protocol. Biological fluids such as blood, cerebrospinal fluid (CSF) and pleural fluid are obtained from invasive pneumonia disease (IPD) patients, if available. All children are tested for SPN using polymerase chain reaction (PCR) and pneumococcal urine antigen test (PUAT) using BinaxNow.DiscussionSurveillance data, including carriage rate, serotype variations and the phylogeny data structure of SPN among young children in Malaysia during PCV implementation, will be generated from this study. Trends and patterns of pneumococcal serotypes by different regions are important for targeted public health strategies. Our data will provide baseline information for estimating the impact of PCV10 implementation and will influence policymakers' decisions regarding the upgrade from PCV10 to a higher-valency conjugate vaccine in Malaysia.Trial registrationThis project was registered at ClinicalTrials.gov (NCT04923035) on 2021, June 11. The study protocol was approved by the International Medical University Joint-Committee on Research & Ethics (4.15/JCM-216/2021) and the Institutional Review Board at sentinel sites (USM/JEPeM/21020190, IREC 2021–114, MREC ID No: 2021128–9769) and University of Southampton's Ethics and Research Governance (ERGo II 64844).

Genome sequences of 36 Streptococcus pneumoniae strains optimized for the multiplexed opsonophagocytosis killing assay.

A multiplexed opsonophagocytosis assay (MOPA) was developed as a cost-effective, high-throughput biological assay to evaluate the efficacy of pneumococcal vaccines by in vitro measurement of opsonophagocytic activity of anti-capsular antibodies. Here, we report draft genomes of the 36 strains of Streptococcus pneumoniae developed for use in the reference pneumococcal MOPA.

Indirect impact of childhood 13-valent pneumococcal conjugate vaccine (PCV13) in Canadian older adults: a Canadian Immunization Research Network (CIRN) retrospective observational study

Background13-valent pneumococcal conjugate vaccine (PCV13) has been part of publicly funded childhood immunisation programmes in Ontario and British Columbia (BC) since 2010. We assessed the indirect impact of infant PCV13...

Pneumococcal Vaccination Rates and Associated Meningitis Events in Patients With Acute Cerebrospinal Fluid Leak.

To characterize the institutional utilization of pneumococcal vaccination during an index hospital admission for acute cerebrospinal fluid (CSF) leakage and associated infectious and clinical outcomes. This retrospective cohort study included patients hospitalized and treated for an acute CSF leak from January 2017 to June 2022. The primary outcome evaluated the incidence of pneumococcal vaccination during the index admission in patients without prior vaccination. Secondary outcomes evaluated the incidence of meningitis, time from CSF leak identification to meningitis, and mortality within 1 year of the index admission. A total of 94 patients were included. Nineteen (20.2%) patients received pneumococcal vaccination prior to admission. Of the 75 patients without prior vaccination, 4 (5.3%) patients received vaccination during the admission. Meningitis occurred in 5/94 (5.3%) patients and occurred 4-24 days from CSF leak identification. Mortality was observed in 9/94 (9.6%) patients. None of the meningitis cases were attributed to culture-positive findings of pneumococcal disease. The results of this study demonstrate an overall low institutional utilization of pneumococcal vaccination in patients with an acute CSF leak. Infectious and clinical outcomes reflected comparable to previous reported literature. Further evaluation into the risk-benefit relationship of vaccination omission is warranted in this patient population.

Attitude of healthcare professionals in Türkiye to COVID-19 vaccine

Background: The COVID-19 vaccine has been effective in reducing infection rates and disease severity; however, vaccination coverage has been lower than expected because of vaccine hesitancy, even among healthcare workers. Aim: To investigate the attitude of healthcare professionals in Türkiye to the COVID-19 vaccine. Methods: This cross-sectional study was conducted between December 2020 and February 2021 among physicians, nurses, midwives, emergency medical technicians, dieticians, and physiotherapists in Türkiye, using the snowball sampling method for data collection. Data were analysed using SPSS version 23 and correlation analysis was conducted to evaluate linear relationship, and multivariate analysis to examine the cause-effect relationship between the variables (α = 0.05). Results: A total of 1057 healthcare professionals participated; average age 38.98 ± 9.044 (min = 19; max = 71), 71.7% (n = 758) women, 69.9% (n = 739) physicians. Of the respondents, 48.3% wanted to be vaccinated whether the vaccine was free or not, 12.1% (n = 128) did not want to be vaccinated and 36.8% were not decided. The most common reasons for wanting to be vaccinated were to end the pandemic (25%, n = 264), seeing vaccination as a good way to prevent COVID-19 disease (30.1%, n = 318), protecting oneself and high-risk individuals from infection (22.2%, n = 235), and hoping that vaccine would reduce the duration and severity of disease (22.9%, n = 242). The most common reasons for not wanting to be vaccinated were fear of side-effects (26.1%, n = 276) and lack of confidence in the reliability of a new vaccine (27.2%, n = 288). The desire to be vaccinated had relationship with influenza vaccination, pneumococcus vaccination, history of COVID-19 infection or contact with a COVID-19 patient, and adherence to infection prevention measures (P &lt; 0.05). Conclusion: Almost half of the healthcare workers in this study were not decided about being vaccinated. To increase acceptance in Türkiye, it is essential to conduct COVID-19 vaccine awareness and education among healthcare professionals because they are perceived as role models in the society, particularly in the health sector.

Potential impact of replacing the 13-valent pneumococcal conjugate vaccine with 15-valent or 20-valent pneumococcal conjugate vaccine in the 1 + 1 infant schedule in England: a modelling study

Paediatric pneumococcal conjugate vaccine (PCV) programmes in England using seven-valent PCV (PCV7) in 2006 and 13-valent PCV (PCV13) in 2010 have reduced vaccine-type invasive pneumococcal disease, but the overall effect has been reduced by an increase in invasive pneumococcal disease due to non-vaccine serotypes and serotype 3. We developed pneumococcal transmission models to investigate the potential effect on invasive pneumococcal disease of higher valency PCVs covering an additional two (ie, 15-valent PCV [PCV15]) or seven serotypes (ie, 20-valent PCV [PCV20]) in England. We conducted a modelling study using realistic, age-structured, and compartmental deterministic models fitted to carriage data from before the introduction of PCVs and invasive pneumococcal disease data from before and after the introduction of PCV7 and PCV13 in England from the UK Heath Security Agency invasive pneumococcal disease surveillance system. We estimated key parameters, including PCV7 and PCV13 efficacy against vaccine-type carriage and invasiveness of PCV7 serotypes; the additional serotypes in PCV13, PCV15 and PCV20; and non-vaccine serotypes. We simulated the effect of transitioning from PCV13 to PCV15 or PCV20 in infants under the current 1 + 1 vaccination schedule and investigated the effect of reduced carriage protection against PCV13 serotypes due to attenuation of immunogenicity in higher valency vaccines. Our results suggest that PCV15 might increase overall invasive pneumococcal disease as the reduction in vaccine-type invasive pneumococcal disease would be counterbalanced by an increase in non-PCV15 invasive pneumococcal disease. By contrast, PCV20 is projected to have a substantial impact on overall invasive pneumococcal disease due to higher invasiveness of the additional serotypes covered by PCV20 than the replacing non-vaccine serotypes. Reduced carriage protection against PCV13 serotypes with higher valency vaccines would amplify these effects. Replacing PCV13 with PCV20 is likely to have a substantial public health benefit, but PCV15 could potentially increase the overall burden of disease. UK Health Security Agency and National Institute of Health Research.

Assessing the Impact of Pneumococcal Conjugate Vaccine Immunization Schedule Change From 3+0 to 2+1 in Australian Children: A Retrospective Observational Study.

In mid-2018, the Australian childhood 13-valent pneumococcal conjugate vaccine schedule changed from 3+0 to 2+1, moving the third dose to 12 months of age, to address increasing breakthrough cases of invasive pneumococcal disease (IPD), predominantly in children aged >12 months. This study assessed the impact of this change using national IPD surveillance data. Pre- and postschedule change 3-dose 13-valent pneumococcal conjugate vaccine breakthrough cases were compared by age group, serotype, and clinical syndrome. Annual rates of breakthrough cases were calculated (per 100 000) using respective birth cohort sizes and 3-dose vaccine coverage. Using time-series modelling, observed IPD rates in children aged <12 years were compared to that expected if the 3+0 schedule were continued. Over 2012-2022, rate of 3-dose breakthrough cases in children aged >12 months was 2.8 per 100 000 (n = 557; 11 birth cohorts). Serotype 3 replaced 19A as predominant breakthrough serotype (respectively, 24% and 65% in 2013 to 60% and 20% in 2022) followed by 19F. In breakthrough cases, the most frequent clinical phenotype was bacteremic pneumonia (69%), with meningitis accounting for 3%-4%. In cohorts eligible for 2+1 versus 3+0 schedules, rate of breakthrough cases was lower for all vaccine serotypes, except type 3 (incidence rate ratio, 0.50 [95% confidence interval, .28-.84] and 1.12 [0.71-1.76], respectively). Observed compared to expected IPD was 51.7% lower (95% confidence interval, -60.9 to -40.7%) for vaccine serotypes, but the change for nonvaccine types was not significant 12% (-9.6 to 39.7). The 2+1 schedule is likely superior to 3+0 for overall IPD control, a finding that may be worth consideration for other countries considering or using 3+0 PCV schedules.

Memory B cell responses induced by pneumococcal conjugate vaccine schedules with fewer doses: analysis of a randomised-controlled trial in Viet Nam

The use of pneumococcal conjugate vaccine (PCV) schedules with fewer doses are being considered to reduce costs and improve access, particularly in low- and middle-income countries. While several studies have assessed their immunogenicity, there are limited data on their potential for long-term immune protection, as assessed by pneumococcal serotype-specific memory B cell (Bmem) responses. This current study reports secondary outcome data that aims to compare Bmem responses following reduced-dose (0 + 1 and 1 + 1) schedules of PCV10 and PCV13 in Vietnamese infants from our randomised-controlled trial (trial registration number NCT03098628). Following vaccination at 12 months of age, Bmem levels for most serotypes peaked seven days post-vaccination and were higher in magnitude for the 1 + 1 than 0 + 1 schedules and for PCV13 than PCV10. Furthermore, Bmem did not wane as rapidly as IgG levels by 24 months of age. Further studies are needed to assess the use of Bmem as markers of long-term protection against pneumococcal carriage and disease, which is crucial to generate data for immunisation program decision-making.

Sex-based difference in immune responses and efficacy of the pneumococcal conjugate vaccine.

Vaccine-mediated protection and susceptibility to Streptococcus pneumoniae (pneumococcus) infections are influenced by biological sex. The incidence of invasive pneumococcal disease remains higher in males compared to females even after the introduction of the pneumococcal conjugate vaccine (PCV). However, sex-based differences in the immune response to this conjugate vaccine remain unexplored. To investigate those differences, we vaccinated adult male and female mice with PCV and assessed cellular and humoral immune responses. Compared to females, male mice displayed lower levels of T follicular helper cells, germinal center B cells and plasmablasts, which are all required for antibody production following vaccination. This was linked to lower IgG and IgM levels against pneumococci and lower isotype switching to IgG3 in vaccinated males. Due to lower antibody levels, sera of vaccinated male mice had lower efficacy in several anti-pneumococcal functions including neutralization of bacterial binding to pulmonary epithelial cells as well as direct cytotoxicity against S. pneumoniae. Importantly, while the vaccine was highly protective in females, vaccinated males succumbed to infection more readily and were more susceptible to both lung-localized infection and systemic spread following S. pneumoniae challenge. These findings identify sex-based differences in immune responses to PCV that can inform future vaccine strategies.

Streptococcus pneumoniae carriage, serotypes, genotypes, and antimicrobial resistance trends among children in Portugal, after introduction of PCV13 in National Immunization Program: A cross-sectional study

Streptococcus pneumoniae carriage studies are crucial to monitor changes induced by use of pneumococcal conjugate vaccines and inform vaccination policies. In this cross-sectional study, we examined changes within the pneumococcal population following introduction of PCV13 in 2015 in the National Immunization Program (NIP), in Portugal. In 2018–2020 (NIP-PCV13), we obtained 1450 nasopharyngeal samples from children ≤6 years attending day-care. We assessed serotypes, antimicrobial resistance, and genotypes (MLST and GPSC) and compared findings with earlier periods: 2009–2010 (pre-PCV13), 2011–2012 (early-PCV13), and 2015–2016 (late-PCV13). Pneumococcal carriage prevalence remained stable at 60.2 %. Carriage of PCV13 serotypes was 10.7 %, markedly reduced compared to pre-PCV13 period (47.6 %). The most prevalent PCV13 serotypes were 19F, 3, and 19A all showing a significant decreasing trend compared to the pre-PCV13 period (from 7.1 % to 4.7 %, 10.1 % to 1.8 %, and 14.1 % to 1.8 %, respectively), a notable observation given the described limited effectiveness of PCV13 against serotype 3. Non-vaccinated children and children aged 4–6 years were more likely to carry PCV13 serotypes (2.5-fold, 95 %CI [1.1–5.6], and 2.9-fold, 95 %CI [1.3–6.8], respectively). The most prevalent non-PCV13 serotypes were 15B/C, 11A, 23B, 23A, and NT, collectively accounting for 51.9 % of all isolates. In total, 30.5 % of all pneumococci were potentially covered by PCV20. Resistance to penicillin (low-level) and macrolides increased significantly, from 9.3 % and 13.4 %, respectively, in the late-PCV13 period, to approximately 20 % each, mostly due to lineages expressing non-PCV13 serotypes, nearing pre-PCV13 levels. An expansion of lineages traditionally associated with PCV13 serotypes, like CC156-GPSC6 (serotype 14) and CC193-GPSC11 (serotype 19F), but now predominantly expressing non-PCV13 serotypes (11A, 15B/C, and 24F for GPSC6; and 15A and 21 for GPSC11) was noted. These findings indicate that the pneumococcal population is adapting to the pressures conferred by PCV13 and antimicrobial use and indicate the need to maintain close surveillance.

New-generation pneumococcal vaccines for children

New-generation pneumococcal vaccines for children

Experimental Human Pneumococcal Carriage using Streptococcus pneumoniae serotype 3 in Malawi: a dose ranging and reproducibility human infection study

Background Streptococcus pneumoniae is a major cause of morbidity and mortality from respiratory tract infections, pneumonia, meningitis, and sepsis. Nasopharyngeal carriage of pneumococcus is a prerequisite for pneumococcal disease and transmission. Since the global introduction of pneumococcal conjugated vaccines, rates of pneumococcal disease have declined for many vaccine type serotypes but serotype 3 (SPN3) continues to cause significant disease. The Experimental Human Pneumococcal Challenge (EHPC) model is a unique method of determining pneumococcal colonisation, understanding the impact of colonisation on acquired immunity and for testing pneumococcal vaccines. This study will develop a serotype 3 EHPC model to address some pertinent questions on the burden of pneumococcal disease in Malawi. Methods Healthy adults aged 18-50 years will be recruited, with a maximum target of 83 participants to complete all study visits. The study will consist of a dose ranging and safety study, followed by a reproducibility study. Sequential cohorts of 10 healthy participants will be challenged with escalating doses of SPN3 in the dose ranging study. Samples will be collected before inoculation and on days 2, 7, 13, 16, 21 and 28 following inoculations, for determination of carriage. A total of 33 participants will be enrolled in the reproducibility part and will use a dose that established ≥60% of carriage, and with a high safety profile. Samples will be collected for determination of both local and systemic immunological responses to pneumococcal challenge. Upon completion of study visits, participants will complete a questionnaire establish acceptability. Interpretations We expect to establish an optimal SPN3 dose required to establish nasopharyngeal colonisation in healthy adults in an EHPC model. The model can then be used to evaluate pneumococcal vaccines in both healthy and at-risk populations.

Therapeutic Management of Bronchiectasis in Children and Adolescents: A Concise Narrative Review.

Introduction: Bronchiectasis, characterized by airway dilation, mucus hypersecretion, and recurrent exacerbations, is increasingly recognized in children and adolescents. Recent guidelines from the European Respiratory Society (ERS) and Thoracic Society of Australia and New Zealand (TSANZ) emphasize early diagnosis and optimized management. This review explores therapeutic strategies for pediatric bronchiectasis. Materials and methods: Our review involved a comprehensive search of English-language literature in the PubMed and EMBASE databases until December 2023, focusing on observational studies, interventions, reviews, and guidelines in pediatric bronchiectasis. Results: Management strategies encompass airway clearance techniques, mucoactive agents, pulmonary rehabilitation, bronchodilators and inhaled corticosteroids tailored to individual needs and age-appropriate techniques. Antibiotics play key roles in preventing exacerbations, eradicating pathogens, and managing acute exacerbations, which are guided by culture sensitivities and symptoms. Long-term antibiotic prophylaxis, particularly macrolides, aims to reduce exacerbations, although concerns about antibiotic resistance persist. Vaccinations, including pneumococcal and influenza vaccines, are crucial for preventing infections and complications. Surgery and lung transplantation are reserved to severe, refractory cases after failure of medical therapies. Conclusions: The optimal management of pediatric bronchiectasis requires a multidisciplinary approach, including physiotherapy, pharmacotherapy, and vaccinations, tailored to individual needs and guided by evidence-based guidelines. Further research is needed to refine diagnostic and therapeutic strategies and improve outcomes for affected children and adolescents.

Health and Economic Benefits of Routine Childhood Immunizations in the Era of the Vaccines for Children Program - United States, 1994-2023.

Since 1994, the U.S. Vaccines for Children (VFC) program has covered the cost of vaccines for children whose families might not otherwise be able to afford vaccines. This report assessed and quantified the health benefits and economic impact of routine U.S. childhood immunizations among both VFC-eligible and non-VFC-eligible children born during 1994-2023. Diphtheria and tetanus toxoids and acellular pertussis vaccine; Haemophilus influenzae type b conjugate vaccine; oral and inactivated poliovirus vaccines; measles, mumps, and rubella vaccine; hepatitis B vaccine; varicella vaccine; pneumococcal conjugate vaccine; hepatitis A vaccine; and rotavirus vaccine were included. Averted illnesses and deaths and associated costs over the lifetimes of 30 annual cohorts of children born during 1994-2023 were estimated using established economic models. Net savings were calculated from the payer and societal perspectives. Among approximately 117 million children born during 1994-2023, routine childhood vaccinations will have prevented approximately 508 million lifetime cases of illness, 32 million hospitalizations, and 1,129,000 deaths, at a net savings of $540 billion in direct costs and $2.7 trillion in societal costs. From both payer and societal perspectives, routine childhood vaccinations among children born during 1994-2023 resulted in substantial cost savings. Childhood immunizations continue to provide substantial health and economic benefits, while promoting health equity.

Changes in the Pneumococcal Vaccination Uptake and Its Determinants before, during, and after the COVID-19 Pandemic among Community-Living Older Adults in Hong Kong, China: Repeated Random Telephone Surveys.

Pneumococcal vaccination (PV) is effective in preventing vaccine-type pneumococcal diseases. This study investigated the changes in PV uptake and its determinants before, during, and after the Coronavirus Disease 2019 (COVID-19) pandemic among community-living older adults aged ≥65 years in Hong Kong, China. Three rounds of random telephone surveys were conducted every two years from May 2019 to October 2023. Multivariate logistic regression models were fitted to examine the between-round differences in PV uptake rate and factors associated with PV uptake in each round. This study included 1563 participants. The standardized PV uptake rate in Round 1, 2, and 3 was 17.3%, 28.3%, and 35.5%, respectively. A significant difference in the PV uptake rate was found between Rounds 2 and 1 (p = 0.02), but not between Rounds 3 and 2 (p = 0.98). Perceived barriers, cue to action and self-efficacy, were significant determinants of PV uptake in all rounds. Perceived benefits were significant determinants of PV uptake in the first and second rounds, but not in the third round. Continuous monitoring of PV uptake and its determinants, and evaluating and adjusting the PV program, might contribute to the success of such a vaccination program in the post-pandemic era.

Secondary Immunodeficiency and Vaccine Response in Rheumatoid and Psoriatic Arthritis on Immunosuppressive Medicines.

Background Rheumatoid arthritis and psoriatic arthritis patients have dysregulated immune system parameters that may increase infection risk at baseline. In addition, treatment of these conditions with immunosuppressive medications may lead to the development of secondary immunodeficiency (SID). Our objective was to assess SID in a cohort on immunosuppressive medications. We hypothesized that SID is clinically detectable by assessing immune parameters and polysaccharide and protein-based vaccination responses. Methodology A prospective cohort study of 42 subjects on immunosuppressive medications was assessed. Analysis included immunoglobulin levels, lymphocyte subsets, and two-step response to diphtheria, tetanus, and 23-valent Streptococcus pneumoniae vaccinations. Exclusions included primary immunodeficiency, malignancy, pregnancy, neutropenia, immunoglobulin replacement, prior B-cell-depleting medication or chemotherapy, use of non-immunosuppressive medication, or recent use of glucocorticoids. Suboptimal vaccine response was defined as an abnormal response based on standard criteria for each vaccine. Results Low IgM levels (below 50 mg/dL) occurred in seven (17%) subjects and IgG (below 650 mg/dL) in three (7%) subjects. Impaired lymphocyte subsets were uncommon. In total, 33 (78%) subjects completed the two-step vaccination assessment. Overall, 29 of 33 (88%) subjects demonstrated suboptimal response to pneumococcal vaccination, 10 (30%) demonstrated suboptimal response to diphtheria, and four (12%) to tetanus. Two (6%) subjects demonstrated suboptimal response to all vaccinations. Finally, 31 (94%) subjects demonstrated suboptimal response to at least one vaccination. Conclusions SID may develop, is clinically detectable, and most notably demonstrated in suboptimal responses to polysaccharide vaccinations, especially against S. pneumoniae.

Novel manufacturing process of pneumococcal capsular polysaccharides using advanced sterilization methods.

Pneumococcal disease is caused by Streptococcus pneumoniae, including pneumonia, meningitis and sepsis. Capsular polysaccharides (CPSs) have been shown as effective antigens to stimulate protective immunity against pneumococcal disease. A major step in the production of pneumococcal vaccines is to prepare CPSs that meet strict quality standards in immunogenicity and safety. The major impurities come from bacterial proteins, nucleic acids and cell wall polysaccharides. Traditionally, the impurity level of refined CPSs is reduced by optimization of purification process. In this study, we investigated new aeration strategy and advanced sterilization methods by formaldehyde or β-propiolactone (BPL) to increase the amount of soluble polysaccharide in fermentation supernatant and to prevent bacterial lysis during inactivation. Furthermore, we developed a simplified process for the CPS purification, which involves ultrafiltration and diafiltration, followed by acid and alcohol precipitation, and finally diafiltration and lyophilization to obtain pure polysaccharide. The CPSs prepared from formaldehyde and BPL sterilization contained significantly lower level of residual impurities compared to the refined CPSs obtained from traditional deoxycholate sterilization. Finally, we showed that this novel approach of CPS preparation can be scaled up for polysaccharide vaccine production.