Diphtheria / Tetanus / Pertussis (acellular component) / Poliomyelitis (inactivated) / Haemophilus type b conjugate vaccine (adsorbed) powder and suspension for suspension for injection 0.5ml pre-filled syringes

Background/Objectives: Haematopoietic stem cell transplantation (HCT) induces profound immunosuppression, significantly increasing susceptibility to severe infections. This review examines vaccinations' necessity, timing, and efficacy post-HCT to reduce infection-related morbidity and mortality. It aims to provide a structured protocol aligned with international and national recommendations. Methods: A systematic review of current guidelines and studies was conducted to assess vaccination strategies in HCT recipients. The analysis included the timing of vaccine administration, factors influencing efficacy, and contraindications. Recommendations for pre- and post-transplant vaccination schedules were synthesised, specifically for graft-versus-host disease (GVHD), immunosuppressive therapy, and hypogammaglobulinemia. Results: Vaccination is essential as specific immunity is often lost after HCT. Inactivated vaccines are recommended to commence three months post-transplant, including influenza, COVID-19, and pneumococcal vaccines. Live attenuated vaccines remain contraindicated for at least two years post-transplant and in patients with ongoing GVHD or immunosuppressive therapy. Factors such as GVHD and immunosuppressive treatments significantly impact vaccine timing and efficacy. The review also underscores the importance of pre-transplant vaccinations and ensuring that patients' close contacts are adequately immunised to reduce transmission risks. Conclusions: Implementing a structured vaccination protocol post-HCT is critical to improving patient outcomes. Timely and effective vaccination strategies can mitigate infection risks while addressing individual patient factors such as GVHD and immunosuppression. This review highlights the need for tailored vaccination approaches to optimize immune reconstitution in HCT recipients.

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BackgroundArmed conflict disrupts health systems and undermines routine immunization, contributing to excess morbidity and mortality. This systematic review examines empirical evidence on the impact of armed conflict on vaccination services and coverage, identifying patterns of disruption across geographic settings and conflict types.MethodsThis study followed PRISMA guidelines and was registered in PROSPERO (CRD420251064804). We searched seven databases for peer-reviewed and grey literature (1985-2025) reporting quantitative comparisons of vaccination coverage before and after conflict onset, or between conflict-affected and unaffected populations. Screening and data extraction followed standardized systematic review protocols, with dual validation of a subset of studies. Due to methodological heterogeneity across studies, a meta-analysis was not conducted.ResultsOf 8,043 citations screened, 33 met the inclusion criteria. Most focused on child immunization in settings across the Eastern Mediterranean (15, 45%) and African (12, 36%) regions. Data sources included household surveys (22, 67%) and health system records (8, 24%). Conflict exposure was most commonly measured using battle-related deaths (15, 45%). Analyses employing individual-level data were most common (10, 30%), followed by subnational administrative data (9, 27%). Nearly all studies (31, 94%) were observational or quasi-experimental. In 28 (85%) studies, conflict was associated with reduced vaccination coverage, sometimes exceeding 20% points for vaccines such as BCG, DTP, and polio. Declines were most pronounced in settings with civil war and moderate to high conflict intensity. Two studies reported localized increases in vaccination coverage, possibly due to targeted humanitarian interventions. Effect estimates were larger in studies using national or administrative-level data compared to those using household-level data, underscoring methodological variation as a key contributor to heterogeneity in reported impacts.ConclusionsArmed conflict is consistently associated with substantial declines in childhood vaccination coverage, most pronounced in civil war and military occupation settings and across conflicts with moderate-to-high annual BRDs. Regional disruptions were especially severe in the Eastern Mediterranean and sub-Saharan African regions. We found substantial variation in estimated effect sizes across analytic units (individual, household, region, country), suggesting that more aggregated data may better capture the broader impact of conflict on vaccination rates. Future research should incorporate standardized conflict and vaccination metrics to improve the generalizability of findings.

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Poliomyelitis, preventable only through vaccination, remains a global health concern, with wild poliovirus transmission and the emergence of vaccine-derived polioviruses. The risk of further deterioration of the situation jeopardizes efforts to eradicate polio, which has been a long-term goal for the whole world. In this systematic review, an analysis of randomized clinical trials was carried out to comprehensively assess the immunogenicity and safety of various polio immunization methods in infants. Geometric mean neutralizing antibody titers (GMT) data collected after 28-31 days after immunization were used to calculate the geometric mean titer ratio (GMR), the analysis of which showed that both inactivated polio vaccine (IPV) and Sabin strain-based inactivated polio vaccine (sIPV) as primary vaccination induce high antibody rates. Average GMR rates (CI = 0.05) for the 3 types of polio were 83.08, 33.60, and 166.30 for IPV and 234.35, 44.04, and 163.13 for sIPV, with fractional IPV showing similar results. One or two doses of IPV were insufficient to induce protection levels of antibodies against type 2 poliovirus. The novel oral polio vaccine type 2 (nOPV2) and trivalent oral polio vaccine (tOPV) also demonstrated immunogenicity in establishing immunity comparable to the inactivated vaccine; the latter exhibited an average GMR of 50.75 for serotype 2. High antibody levels were also induced by combined vaccine schedules, with sIPV-sIPV-bOPV (GMR of 1,172.7 for type 1 and 887.6 for type 3) and IPV combinations with diphtheria-tetanus-whole-cell pertussis, hepatitis B and Haemophilus influenzae type b (351.2, 258.8, and 573.6 for the 3 types) or pentavalent rotavirus vaccine (354.6, 117.7, and 540.9 for the 3 types) establishing particularly high antibody levels. Analysis of adverse events presented all vaccines to be well-tolerated and safe, with a tendency for combination vaccines to have a higher frequency of local reactions and fever. While the studies presented a diverse landscape with some existing areas of concern, this review provides structured evidence supporting the safety and immunogenicity of existing polio vaccines, as well as highlighting the interchangeability of different vaccination approaches in infants. Future research should aim to provide detailed reporting of adverse events in order to facilitate more comprehensive assessment of vaccine immunogenicity and, therefore, efficacy.

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ObjectiveTo determine the evidence for non-specific effects of the Pneumococcal and Haemophilus influenza vaccine in children aged 5 years and under.Data sourcesA key word literature search of MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials, the European Union Clinical Trials Register and ClinicalTrials.gov up to June 2023.Study eligibility criteriaRandomised controlled trials (RCTs), quasi-RCT or cohort studies.ParticipantsChildren aged 5 or under.Study appraisal and synthesis methodsStudies were independently screened by two reviewers, with a third where disagreement arose. Risk of bias assessment was performed by one reviewer and confirmed by a second. Results were tabulated and a narrative description performed.ResultsFour articles were identified and included in this review. We found a reduction in hospitalisations from influenza A (44%), pulmonary tuberculosis (42%), metapneumovirus (45%), parainfluenza virus type 1-3 (44%), along with reductions in mortality associated with pneumococcal vaccine. No data on the Haemophilus vaccine was found.Conclusions and implicationsIn this systematic review, we demonstrate that there is a reduction in particular viral infections in children aged 5 years and under who received the 9-valent pneumococcal conjugate vaccine which differ from those for which the vaccine was designed to protect against. While limited studies have demonstrated a reduction in infections other than those which the vaccine was designed to protect against, substantial clinical trials are required to solidify these findings.Prospero registration numberCRD42020146640.

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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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IntroductionGross domestic product (GDP) has been shown to affect government spending on various budget heads including healthcare and the purchase and distribution of vaccines. This vulnerable situation has been exacerbated by the COVID-19 pandemic which disrupted and exposed the fragile nature of equitable access to vaccines for childhood immunisation globally. A systematic review and meta-analysis to assess the association of country income status and GDP with vaccination coverage of vaccines for childhood immunisation and other major infectious diseases around the globe will inform global and national policy on equity in living standards and vaccine uptake. This study was carried out to identify factors influenced by GDP that affect access, distribution, and uptake of childhood vaccines around the world using a systematic review and meta-analysis approach.MethodsData were extracted for the burden of major infectious diseases of childhood immunisation programmes, factors affecting access to vaccines, vaccine procurement platforms, vaccination coverage and percentage of GDP used for the procurement of vaccines. Factors influencing the global vaccination coverage rate were also assessed. The protocol was registered on PROSPERO (ID: CRD42022350418) and carried out using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.ResultsData from 195 countries showed that the following infectious diseases had the highest burden; human papillomavirus (HPV), measles, Ebola and yellow fever. Low-income and some lower-middle-income countries (LMICs) used COVAX and UNICEF for vaccine procurement while high-income countries (HICs) preferred national and regional public tenders. Global vaccination coverage for tuberculosis, diphtheria/tetanus/pertussis, hepatitis B, Haemophilus influenzae type b, measles, polio, meningitis and HPV had a significantly higher coverage than COVID-19. Being an HIC and having coverage data collected from 1985 to 2015 as the most current data were associated with high vaccination coverage. The percentage of GDP spent on vaccine procurement did not influence vaccination coverage.ConclusionLow-income countries and LMICs should prioritise vaccine research and improve on development capacity. Countries worldwide should share data on vaccine expenditure, vaccination coverage, and the development and introduction of new vaccines and technologies to facilitate equitable vaccine access.

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BackgroundWHO, as requested by its member states, launched the Expanded Programme on Immunization (EPI) in 1974 to make life-saving vaccines available to all globally. To mark the 50-year anniversary of EPI, we sought to quantify the public health impact of vaccination globally since the programme's inception.MethodsIn this modelling study, we used a suite of mathematical and statistical models to estimate the global and regional public health impact of 50 years of vaccination against 14 pathogens in EPI. For the modelled pathogens, we considered coverage of all routine and supplementary vaccines delivered since 1974 and estimated the mortality and morbidity averted for each age cohort relative to a hypothetical scenario of no historical vaccination. We then used these modelled outcomes to estimate the contribution of vaccination to globally declining infant and child mortality rates over this period.FindingsSince 1974, vaccination has averted 154 million deaths, including 146 million among children younger than 5 years of whom 101 million were infants younger than 1 year. For every death averted, 66 years of full health were gained on average, translating to 10·2 billion years of full health gained. We estimate that vaccination has accounted for 40% of the observed decline in global infant mortality, 52% in the African region. In 2024, a child younger than 10 years is 40% more likely to survive to their next birthday relative to a hypothetical scenario of no historical vaccination. Increased survival probability is observed even well into late adulthood.InterpretationSince 1974 substantial gains in childhood survival have occurred in every global region. We estimate that EPI has provided the single greatest contribution to improved infant survival over the past 50 years. In the context of strengthening primary health care, our results show that equitable universal access to immunisation remains crucial to sustain health gains and continue to save future lives from preventable infectious mortality.FundingWHO.

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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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