Diphtheria / Tetanus / Pertussis (acellular component) vaccine (adsorbed) injection pre-filled syringes / Haemophilus type b conjugate vaccine injection vials

Background: Co-administration of vaccines can impact the immune response and safety. We aim to systematically review the current scientific literature and find evidence regarding the immunogenicity and safety of pneumococcal vaccines co-administered with common vaccines that are recommended for travelers, including hepatitis A, hepatitis B, yellow fever, tetanus, diphtheria, and acellular pertussis (Tdap), Japanese encephalitis, rabies, typhoid, or meningococcal (MCV) vaccine in adults (18 years or older). Methods: We followed the PRISMA 2020 guidelines and used the PICOS process to select the keywords. We searched PubMed, Web of Science, Scopus, EMBASE, and Google from 1 January 2000 to 30 June 2024. We included randomized controlled trials, non-randomized controlled trials, observational studies, case series, and case reports in adults, all published in English. Results: Out of 598 articles screened, 6 studies were included in our study. Three studies involved immunocompetent individuals, and three involved immunocompromised individuals. Co-administration of pneumococcal vaccine with Tdap or Hepatitis A in immunocompetent individuals was safe and immunogenic. Similar findings were reported for immunocompromised individuals when pneumococcal vaccines were co-administered with Tdap, hepatitis A, and hepatitis B. However, no reports investigated the co-administration of yellow fever, rabies, Japanese encephalitis, and typhoid. Two non-randomized studies in immunocompromised individuals had a high risk of bias. Conclusions: The studies collectively indicate that the co-administration of pneumococcal vaccines with Hepatitis A and Tdap vaccines in adult immunocompetent and immunocompromised individuals is safe and immunogenic. However, a knowledge gap remains, and further high-quality studies are needed, particularly due to the limited number of studies and the potential risk of bias.

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ObjectiveTo systematically review and critically appraise human evidence on potential health effects of aluminium adjuvanted vaccines.DesignSystematic review following PRISMA (preferred reporting items for systematic review and meta-analysis) 2020 guidelines.Data sourcesSix databases and trial registries were searched from inception to 3 March 2023 then updated to 27 November 2025. Reference lists of eligible studies were also screened.Eligibility criteria for selecting studiesHuman studies assessing health outcomes after aluminium adjuvanted vaccination, including randomised controlled trials, cohort studies, case series, and ecological studies. Investigational vaccines, case reports, and review articles were excluded.Data extraction and synthesisTwo reviewers screened studies (with AI assistance for the 2023-25 update), extracted data, and assessed risk of bias (using RoB 2.0, ROBINS-I, or an adapted tool for case series). Certainty of evidence was rated using GRADE (Grading of Recommendations Assessment, Development, and Evaluation).ResultsThe review included 59 studies (37 case series, 11 randomised controlled trials, nine cohort studies, two ecological studies). High quality evidence from randomised controlled trials and large cohorts consistently showed no association between aluminium adjuvanted vaccines and serious or long term health outcomes, such as asthma, autism spectrum disorders, or other chronic conditions. Studies on macrophagic myofasciitis were generally small and methodologically limited, and did not provide credible evidence of a causal association (very low certainty). Localised persistent nodules or granulomas were observed infrequently after diphtheria-tetanus-pertussis vaccines, consistent with delayed type hypersensitivity (ConclusionsCurrent evidence does not support causal associations between aluminium adjuvanted vaccines and serious or long term health outcomes. The most consistently documented reactions were persistent nodules or granulomas that are uncommon, local, and self-limited hypersensitivity reactions. These findings are broadly consistent with post-licensure surveillance findings. The predominance of methodologically limited studies for some outcomes highlights the need for higher quality research.Systematic review registrationPROSPERO CRD42023462831.

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BackgroundAcute lymphoblastic leukemia is the most prevalent childhood cancer and the leading cause of cancer mortality before the age of 20. Although therapeutic advances have significantly improved survival, children and adolescents treated for acute lymphoblastic leukemia remain vulnerable to infections, largely preventable by vaccination, due to humoral and cellular immune dysfunction induced by disease and treatment.Materials and methodsThis systematic review, based on electronic databases, aims to evaluate antibody levels associated with potential protective immunity against vaccine antigens for diphtheria, pertussis, tetanus, poliomyelitis, Haemophilus influenzae type b, measles, mumps, rubella, influenza, varicella-zoster virus, yellow fever, pneumococcal, and meningococcal diseases in children and adolescents treated for acute lymphoblastic leukemia after completion of chemotherapy.ResultsA total of twenty-four studies published between 1981 and 2023 were included, comprising 1110 children and adolescents. Protective antibody levels ranged from 11% to 97% for diphtheria, 0% to 90% for pertussis, 20% to 100% for tetanus, and 11% to 95% for poliomyelitis. Haemophilus influenzae type b, protection ranged from 16.7% to 100%. Viral vaccines also showed heterogeneous responses, with protection rates of 25-79% for mumps, 16-86% for measles, 35-98% for rubella, and 23-75% for varicella-zoster virus. Antibody responses to pneumococcal and meningococcal vaccines were consistently low, with protection rates of 5-38% for pneumococcal studies and 12% in a single meningococcal study.ConclusionsThis review found a consistent and clinically relevant loss of vaccine-induced immunity in children and adolescents treated for acute lymphoblastic leukemia. The recommendation of vaccine booster doses for this vulnerable population, irrespective of serological status, may represent a more practical approach to ensuring adequate post-chemotherapy treatment protection.

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ObjectivesGrowing evidence suggests that vaccines targeting respiratory pathogens have non-specific and broader effects. We aimed to investigate the non-specific effects of respiratory vaccines on acute lower respiratory infection (ALRI) hospitalisations and associated outcomes in children DesignSystematic review and meta-analysis.Data sourcesWe searched online databases including Medline, Embase, CINAHL, Scopus and Clinical Trials.gov from inception to 24 January 2024.Eligibility criteriaWe included human studies involving non-specific/off-target effects of respiratory vaccines (including maternal, infant and childhood vaccines) and excluded studies investigating the Bacille Calmette-Guérin vaccine and non-pathogen-confirmed outcomes following pneumococcal conjugate vaccination (PCV).Data extraction and synthesisWe used Research Screener, a machine learning tool, to semi-automate the abstract screening process and Covidence, a management and streamlining software for full-text reviews and data extraction. A meta-analysis was conducted if four or more studies reported on the same outcome and the same exposure vaccine.ResultsAfter removing duplicates, 9727 articles were identified. After screening and full-text reviews, 20 articles were eligible. Of those, four met the requirements for a meta-analysis which showed a 21% vaccine effectiveness (VE) (95% CI 8.0% to 32.0%) of maternal influenza vaccine against all-cause ALRI hospitalisations in infants ConclusionsOur review demonstrated both protective and neutral non-specific effects of respiratory vaccines against ALRI-hospitalisations and related outcomes in young children. Such effects should be considered as part of the full value of a vaccine and how vaccine investments are prioritised. Further research on the impact of respiratory vaccines on antibiotic prescribing rates is essential as consistent reductions may help contribute to reducing the global burden of antimicrobial resistance.Prospero registration numberCRD 42023476038.

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Hydro-meteorological and geological disasters can pose serious harm to community health, such as an increased risk of infectious diseases and related mortality. We conducted a scoping review to compile the available literature on the effects of hydro-meteorological and geological disasters on routine immunisation and vaccine-preventable disease (VPD) outbreaks among children and adolescents under 18 years. We searched Medline, Embase, Global Health, Scopus, and Web of Science for original studies and systematic reviews on the topic published by the 21st of October 2024. We included studies that quantitatively analysed the effect of any of the thirty Emergency Events Database (EM-DAT) recognised hydro-meteorological and geological disasters (or those fitting EM-DAT criteria) on a comprehensive list of World Health Organization (WHO)-recommended vaccines and the 23 diseases against which they prevent. We included 26 studies, of which 19 concerned with vaccine-preventable disease outbreaks and seven focused on routine immunisation disruption.. Our review indicates that floods, cyclones, droughts, extreme temperatures, tsunamis, and earthquakes may result in vaccine-preventable disease outbreaks and routine immunisation disruption, and identified young children and refugees as at-risk populations. Flooding was reported to be associated with water-borne and vector-borne vaccine-preventable disease outbreaks such as malaria. Poor water, sanitation and hygiene (WASH) were further recognised as facilitating conditions for vaccine-preventable disease outbreaks after disasters. The vaccination studies reported reduction in routine immunisation rates in the months following a disaster, considering infrastructural damage to health facilities and vaccine storage issues as common causes. Finally, there was significant knowledge gap on the effects of specific disasters (e.g., wildfires and volcanic eruptions) and diseases (e.g., influenza, yellow fever, malaria, and dengue).In conclusion, our review reinforce the need for better policies to ensure vaccine equity, resilient health system and safe WASH to prevent vaccine-preventable disease (VPD) outbreaks following hydro-meteorological and geological disasters.

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BackgroundFunctional active safety surveillance is essential for post-authorization assessment and life-cycle safety evidence generation of vaccines and medicines. Data collected through active surveillance methods are routinely used for post-approval surveillance of novel vaccines and medicines. Implementing these methods in low- and middle-income countries remains challenging.ObjectiveThis systematic review identified and assessed existing active safety surveillance in low- and middle-income countries, including key features, strengths, and limitations.MethodsA search of EMBASE and PubMed Google Scholar databases was conducted. The protocol was registered with PROSPERO and adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. Findings were synthesized narratively and categorized by surveillance systems characteristics.ResultsOf 13,027 records identified, 423 publications met inclusion criteria. Articles spanned 96 low- and middle-income countries, with India (96), China (57), Brazil (30), Iran (26), Ethiopia (21), Indonesia (20), Uganda (18), Kenya (17), and Ghana (16), most represented. The majority focused on vaccines (211). A total of 127 articles utilized mobile technologies for follow-up, online data collection, and/or adverse event reporting. Fifteen percent of vaccine surveillance systems described in articles demonstrated flexibility to incorporate new vaccines, 34% reported multi-sectoral collaborations, and 10% involved multiple countries. Gaps identified include small sample sizes, lack of sustainability, limited flexible surveillance, staffing challenges, and limited use of standard case definitions and digital technologies.ConclusionsActive safety surveillance in low- and middle-income countries has made progress but still faces challenges. The capture and management of safety data through harmonized digital tools that promote consistency in recording and reporting and cross-country collaborations are crucial in further strengthening active safety surveillance in low- and middle-income countries.

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