Search Results (1,140)

The association between COVID-19 vaccination and thromboembolic events has garnered significant research attention, particularly with the advent of vaccines based on adenoviral vectors, including AstraZeneca’s and Johnson & Johnson’s vaccines. This review underscores the uncommon occurrence of venous thromboembolism (VTE), arterial thromboembolism (ATE), and vaccine-induced thrombotic thrombocytopenia (VITT) following COVID-19 vaccination. Although these complications are extremely rare compared to the heightened risk of thrombosis from COVID-19 infection, elements like age, biological sex, type of vaccine and underlying health conditions may contribute to their development. In addition, rare renal complications such as acute kidney injury and thrombotic microangiopathy have been documented, broadening the spectrum of potential vaccine-associated thrombotic manifestations. Current guidelines emphasize early detection, individualized risk assessment, and use of anticoagulation therapy to mitigate risks. Despite these events, the overwhelming majority of evidence supports the continued use of COVID-19 vaccines, given their proven efficacy in reducing severe illness and mortality. In addition, recent comparative data confirm that mRNA-based vaccines are associated with a significantly lower risk of serious thrombotic events compared to adenoviral vector platforms. Ongoing research is essential to further refine preventive and therapeutic strategies, particularly for at-risk populations. Full article

Background/Objectives: Mucosal vaccines, delivered intranasally or via inhalation, are being studied for respiratory infectious diseases like COVID-19 and influenza. These vaccines aim to provide non-invasive administration and strong immune responses at infection sites, making them a promising area of research. This systematic review and meta-analysis assessed their immunogenicity, safety, and protective efficacy. Methods: The study design was a systematic review and meta-analysis, searching PubMed and Cochrane databases up to 30 May 2025. Inclusion criteria followed the PICOS framework, focusing on mucosal vaccines for COVID-19, influenza, RSV, pertussis, and tuberculosis. Results: A total of 65 studies with 229,614 participants were included in the final analysis. Mucosal COVID-19 vaccines elicited higher neutralizing antibodies compared to intramuscular vaccines (SMD = 2.48, 95% CI: 2.17–2.78 for wild-type; SMD = 1.95, 95% CI: 1.32–2.58 for Omicron), with varying efficacy by route (inhaled VE = 47%, 95% CI: 22–74%; intranasal vaccine VE = 17%, 95% CI: 0–31%). Mucosal influenza vaccines protected children well (VE = 62%, 95% CI: 30–46%, I² = 17.1%), but seroconversion rates were lower than those of intramuscular vaccines. RSV and pertussis vaccines had high seroconversion rates (73% and 52%, respectively). Tuberculosis vaccines were reviewed systemically, exhibiting robust cellular immunogenicity. Safety was comparable to intramuscular vaccines or placebo, with no publication bias detected. Conclusions: Current evidence suggests mucosal vaccines are immunogenic, safe, and protective, particularly for respiratory diseases. This review provides insights for future research and vaccination strategies, though limitations include varying efficacy by route and study heterogeneity. Full article

Background: Vaccine hesitancy (VH) represents a growing concern among healthcare professionals and students, potentially undermining public health efforts. Nursing, pediatric nursing, and midwifery students are future vaccinators and educators, making it essential to understand their attitudes, knowledge, and confidence toward vaccination. This study aims to assess vaccine-related perceptions and behaviors among these student populations in an Italian university. Methods: A cross-sectional survey was conducted between November 2022 and February 2024 at the University of Rome “Tor Vergata”. A structured, anonymous questionnaire, including the Vaccination Attitudes Examination (VAX) scale, vaccine knowledge items, and sources of information, was administered to students in nursing (n = 205), pediatric nursing (n = 46), and midwifery (n = 21). Statistical analyses included descriptive statistics, ANOVA, post hoc tests, and Mann–Whitney U tests. Results: Among the 272 participants, 20.6% reported refusing at least one recommended vaccine, and 18.4% delayed vaccination for non-medical reasons. Vaccine knowledge and confidence increased significantly with academic progression (p < 0.001). Midwifery students showed both the highest concern for long-term vaccine effects and the greatest confidence in vaccine safety. Institutional and scientific sources were the most trusted, though traditional and non-institutional media also influenced perceptions, particularly among midwifery students. Conclusions: Despite high COVID-19 vaccine uptake, VH persists among health professional students. Discipline-specific patterns highlight the need for early, targeted educational strategies to enhance vaccine literacy and reduce hesitancy. Tailored training may empower future professionals to become informed and credible advocates for vaccination. Full article

Recombinant vesicular stomatitis virus (rVSV) is a promising viral vaccine vector for addressing the COVID-19 pandemic. Inducing mucosal immunity via the intranasal route is an ideal strategy for rVSV-based vaccines, but it requires extremely stringent safety standards. In this study, we constructed two rVSV variants with amino acid mutations in their M protein: rVSV-M2 with M33A/M51R mutations and rVSV-M4 with M33A/M51R/V221F/S226R mutations, and developed COVID-19 vaccines based on these attenuated vectors. By comparing viral replication capacity, intranasal immunization, intracranial injection, and blood cell counts, we demonstrated that the M protein mutation variants exhibit significant attenuation effects both in vitro and in vivo. Moreover, preliminary investigations into the mechanisms of virus attenuation revealed that these attenuated viruses can induce a stronger type I interferon response while reducing inflammation compared to the wild-type rVSV. We developed three candidate vaccines against SARS-CoV-2 using the wildtype VSV backbone with either wild-type M (rVSV-JN.1) and two M mutant variants (rVSV-M2-JN.1 and rVSV-M4-JN.1). Our results confirmed that rVSV-M2-JN.1 and rVSV-M4-JN.1 retain strong immunogenicity while enhancing safety in hamsters. In summary, the rVSV variants with M protein mutations represent promising candidate vectors for mucosal vaccines and warrant further investigation. Full article

The uptake of the COVID-19 and seasonal influenza (SI) vaccines have decreased in Europe and especially in Malta. The present study aimed to investigate the attitudes toward COVID-19 and SI vaccines and determine if individuals perceive that these vaccines are relevant to protect their health and identify reasons for their responses. A cross-sectional study using an anonymous questionnaire, informed by the Theory of Planned Behavior, addressing behavior beliefs and attitudes, and targeted at adult residents in Malta, was designed on Google Forms and disseminated using social media between January and March 2024. A total of 555 responses were received. The majority of respondents did not take/intend to take the COVID-19 (75%, n = 417) or SI (64.3%, n = 362) vaccines, with females being less likely to do so (p = 0.033). Perceived lack of safety (31.3%, n = 174) was the primary reason for rejecting the COVID-19 vaccine, and perceived lack of a threat from SI (26%, n = 144) was the reason for rejecting the SI vaccine. Those having chronic conditions were positively associated with uptake of both vaccines. In the post-pandemic era, these vaccines are not envisaged as having a major role in protecting one’s health. A high degree of skepticism especially toward the combined COVID-19 and SI vaccine in terms of safety, mostly in women, is still present. Full article

The COVID-19 pandemic accelerated the rapid development and distribution of various vaccine platforms, resulting in a significant reduction in disease severity, hospitalizations, and mortality. However, persistent challenges remain concerning the durability and breadth of vaccine-induced protection, especially in the face of emerging SARS-CoV-2 variants. This review aimed to evaluate the factors influencing the immunogenicity and effectiveness of COVID-19 vaccines to inform future vaccine advancement strategies. A narrative review with systematic approach was conducted following PRISMA guidelines for narrative review. Literature was sourced from databases including PubMed, Embase, and Web of Science for studies published between December 2019 and May 2025. Encompassed studies assessed vaccine efficacy, immunogenicity, and safety across various populations and vaccine platforms. Data were collected qualitatively, with quantitative data from reviews highlighted where available. We have uncovered a decline in vaccine efficacy over time and weakened protection against novel variants such as Delta and Omicron. Booster doses, specifically heterologous regimens, improved immunogenicity and increased protection. Vaccine-induced neutralizing antibody titers have been found to correlate with clinical protection, although the long-term correlates of immunity remain poorly defined. The induction of IgG4 antibodies after repeated mRNA vaccinations raised concerns about potential modulation of the immune response. COVID-19 vaccines have contributed significantly to pandemic control; however, their efficacy is limited by the evolution of the virus and declining immunity. Forthcoming vaccine strategies should focus on broad-spectrum, variant-adapted formulations and defining robust comparisons of protection. Recognizing the immunological basis of vaccine response, including the role of specific antibody subclasses, is fundamental for optimizing long-term protection. Full article

Background: We previously reported an interim safety and immunogenicity analysis of a Phase 3 trial in the Philippines of the EuCorVac-19 (ECV-19) COVID-19 vaccine with the COVISHIELD^TM (CS) comparator (ClinicalTrials.gov identifier NCT05572879). Here, we present full-year humoral immunogenicity analysis. Methods: Healthy adults over 18 years of age received two injections of ECV-19 or CS vaccines, with 4 weeks between prime and boost. Analysis was carried out in individuals with immunogenicity measurements available at all 4 timepoints (weeks 0, 6, 30, and 56; n = 535 for ECV-19 and n = 260 for CS). Results: 2 weeks after boosting (week 6), ECV-19 elicited higher median anti-RBD IgG (1512 vs. 340 BAU/mL, p < 0.001) and neutralizing antibodies (1280 vs. 453 median microneutralization (MN) titer, p < 0.001) compared to CS. Anti-RBD IgG remained higher for ECV-19 compared to CS through week 30 (412 vs. 238 BAU/mL, p < 0.001) and 56 (425 vs. 260 BAU/mL, p < 0.001). MN titers remained higher for ECV-19 compared to CS through week 30 (640 vs. 453, p < 0.001) and 56 (453 vs. 320, p < 0.001). Correlation between anti-RBD IgG and neutralization titers persisted throughout the study. Women generally exhibited greater antibody responses than men. In the first six months following immunization, the ECV-19 group had a median antibody half-life of 80 days for anti-RBD IgG and 112 days for MN titer. In the subsequent six months, antibody half-life increased to 237 days for anti-RBD IgG and 168 days for MN titer. Conclusions: Following initial prime-boost vaccination, ECV-19 maintained higher anti-RBD IgG and neutralizing antibody titers relative to the CS comparator over a full-year period. Full article

The 100-Day Mission, coordinated by the Coalition for Epidemic Preparedness Innovations (CEPI) and endorsed by significant international stakeholders, aims to shorten the timeframe for developing and implementing vaccines to 100 days after the report of a new pathogen. This ambitious goal is outlined as an essential first step in improving pandemic preparedness worldwide. This review highlights the mission’s implementation potential and challenges by examining it through the lens of low- and middle-income countries (LMICs), which often face barriers to equitable vaccine access. This article explores the scientific, economic, political, and social aspects that could influence the mission’s success, relying on lessons learned from previous pandemics, such as the Spanish flu, H1N1, and COVID-19. We also examined important cornerstones like prototype vaccine libraries, accelerated clinical trial preparedness, early biomarkers identification, scalable manufacturing capabilities, and rapid pathogen characterization. The review also explores the World Health Organization (WHO) Pandemic Agreement and the significance of Phase 4 surveillance in ensuring vaccine safety. We additionally evaluate societal issues that disproportionately impact LMICs, like vaccine reluctance, health literacy gaps, and digital access limitations. Without intentional attempts to incorporate under-resourced regions into global preparedness frameworks, we argue that the 100-Day Mission carries the risk of exacerbating already-existing disparities. Ultimately, our analysis emphasizes that success will not only rely on a scientific innovation but also on sustained international collaboration, transparent governance, and equitable funding that prioritizes inclusion from the beginning. Full article

Background: Myocarditis and pericarditis are recognised risks following COVID-19 vaccination, including the mRNA-1273 vaccine. Most cases occur shortly following the second dose of this vaccine, and incidence is highest among young males. However, little is known about risk factors beyond age and sex and about the longer-term clinical course. This study aims to identify possible risk factors for myocarditis and pericarditis following mRNA-1273 vaccination, to characterise the clinical course of myocarditis and pericarditis, both associated with mRNA-1273 vaccination and not associated with vaccination, and to identify risk factors for severe outcomes (i.e., cardiac or thromboembolic complications, severe hospital outcomes, all-cause hospital readmission, and death). Methods: This study is being conducted within the Vaccine Monitoring Collaboration for Europe (VAC4EU) association using routinely collected healthcare data from five data sources from four European countries (Denmark, Norway, Spain, and the United Kingdom). The study is being performed using a common data model, and all analyses are performed separately in each data source in a federated manner following a common protocol. A case–cohort analysis set is identified within each data source for identifying potential risk factors for myocarditis and pericarditis following mRNA-1273 vaccination using logistic regression analysis. The clinical course of myocarditis and pericarditis is being assessed using a cohort study design and describes all cases (i.e., cases associated with mRNA-1273 and unexposed cases). Cox regression analysis is applied to assess the associations between risk factors and several follow-up outcomes. Conclusions: This protocol describes the study methodology of an international collaborative initiative with the aim of assessing the risk factors and clinical course of myocarditis and pericarditis following mRNA-1273 vaccination using a federated network of five European data sources. Full article

This study provides a detailed analysis of COVID-19-related social media discourse in Italy, using 535,886 tweets from 10 major cities between 30 August 2020 and 8 June 2021. The tweets were translated from Italian to English for analysis. A multifaceted methodology was employed: Latent Dirichlet Allocation (LDA) identified 20 key themes; sentiment analysis, using TextBlob, Flair, and TweetNLP, and emotion recognition using TweetNLP, revealed the emotional tone of the discourse, with 453 tweets unanimously positive across all algorithms. TextBlob was used for lexical analysis to rank the most salient positive and negative terms. The results indicated that positive sentiments centered on hope, safety measures, and vaccination progress, while negative sentiments focused on fear, death, and quarantine frustrations. This research offers valuable insights for public health officials, enabling tailored messaging, real-time strategy monitoring, and agile policymaking during the pandemic, with implications for future health crises. Full article

Background: Retinal vascular occlusion (RVO) and retinal artery occlusion (RAO) have been reported as rare adverse events following COVID-19 vaccination, raising concerns about vaccine safety. This review synthesizes cohort and case–control studies assessing the association between COVID-19 vaccines and RVO/RAO, while exploring potential pathophysiological mechanisms. Methods: We analyzed large-scale population-based studies from South Korea, Europe, and the TriNetX database, focusing on odds ratios (OR), hazard ratios (HR), and relative risks (RR) across mRNA and adenoviral vector vaccines. Pathological processes were hypothesized based on molecular and clinical evidence. Results: Studies investigating the association between COVID-19 vaccination and retinal vascular occlusion show conflicting results; some studies report no association (e.g., OR 0.93, 95% CI 0.60–1.45), others suggest reduced risk (e.g., OR 0.80, 95% CI 0.64–0.99), and one indicates increased risk over two years (HR 2.19, 95% CI 2.00–2.39). Adenoviral vector vaccines, particularly ChAdOx1, show higher RAO incidence in specific cohorts. Proposed mechanisms include vaccine-induced immune thrombotic thrombocytopenia (VITT) via anti-PF4 antibodies, spike protein-mediated endothelial dysfunction, and adjuvant-driven inflammation. Conclusions: While causality remains unproven, temporal heterogeneity and vaccine type-specific risks warrant further investigation. Longitudinal studies with robust controls are needed to clarify these associations in the post-pandemic context. Full article

Introduction: COVID-19 and influenza are viruses that have been major causes of morbidity and mortality worldwide. While a combination vaccine for these two viruses is currently in development, little is known about public perceptions and attitudes towards such a vaccine. Therefore, we have aimed to conduct a scoping review to evaluate the attitudes and reasons for the acceptance/rejection of a combination COVID-19 and influenza vaccination. Material and Methods: Our review has followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-ScR) guidelines. Search terms included those on COVID-19, influenza, and combination vaccines. Searches were conducted in a total of 10 different databases, as follows: Embase, Global Health, Google Scholar, CINAHL, Medline, Scopus, ScienceDirect, PubMed, PsycINFO, and Web of Science. Results: Searches across all databases produced a total of 1763 results, of which five studies were deemed to be eligible for this review. Data from included studies encompassed a total of 20,581 participants across 14 countries. Generally, participants had favorable views towards a combination vaccine. However, attitudes varied by region, demographics, and prior vaccine exposure. Reasons provided for accepting a combination vaccine include low cost, reasonable effectiveness, fewer injections, and higher safety. However, reasons for rejection of a potential combination vaccine include a potential lack of evidence and studies regarding its effectiveness and a fear of possible side effects. Conclusions: There are generally positive attitudes and perceptions towards a combination vaccination for COVID-19 and influenza, and there are also specific segments of populations that may show hesitancy towards such a vaccine. Vaccination delivery programs should clearly demonstrate that these vaccines are safe and must concurrently address false rumors and misinformation. Ensuring that as many people as possible can receive the vaccination without barriers via equity in access should be a public health priority. It is also important to recognize the limitations of this work, especially that the review was limited to five studies, the majority of which were cross-sectional and relied on self-reporting. Full article

Background: The COVID-19 pandemic prompted extensive vaccination efforts globally, yet in the Philippines, many families remained unvaccinated. Caregivers are key decision-makers for family vaccination, but evidence on factors influencing their own vaccine uptake is limited. Methods: A cross-sectional survey of primary caregivers was conducted in low COVID-19 vaccine uptake regions in the Philippines from July to October 2023 using a validated questionnaire. Multivariable logistic regression identified enablers and barriers to vaccine uptake. Results: Among 775 respondents, 72.3% completed primary vaccination, 3.3% had incomplete vaccination, and 24.4% were unvaccinated. Key factors for vaccination included self, family, and community protection, and the influence of government regulations. Distrust in vaccine safety was the main barrier. Positive associations with vaccine uptake were found for age [30–45 years (aOR = 2.23) and 46–59 years (aOR = 2.84)], education [secondary (aOR = 2.25) and tertiary (aOR = 4.93)], and employment (aOR = 1.99). Confidence in vaccine safety (aOR = 1.92), vaccine effectiveness (aOR = 2.23), and satisfaction with vaccination efforts (aOR = 2.39) were additional enablers. Disagreement with restrictions on the unvaccinated was a barrier (aOR = 0.31). Conclusions: This study identified multiple factors influencing COVID-19 vaccination among primary caregivers in low uptake areas of the Philippines. Interventions addressing perceptions about vaccine safety and effectiveness, particularly among younger and less educated caregivers, may improve public trust and satisfaction with vaccination efforts. Full article

Background/Objectives: The COVID-19 pandemic significantly threatened cancer patients and oncologic care. The rollout of vaccines emerged as a critical milestone, despite the initial lack of evidence regarding their safety and efficacy in this population. This systematic review and meta-analysis evaluate the current evidence on COVID-19 vaccination in patients undergoing radiotherapy (RT). Methods: PubMed, Livivo, Scopus, and Cochrane Library were systematically reviewed for relevant publications on COVID-19 vaccination in the context of radiation oncology, published by 19 April 2024. The treatment effects were calculated as the proportion of seroconverted individuals. Results: A total of 22 studies published between 2021 and 2024 were included, covering various aspects of vaccination, including safety, tolerability, qualitative and quantitative humoral responses, cellular responses, vaccination efficacy, and booster vaccinations. Notably, patients undergoing RT exhibited a high willingness to receive vaccination. Vaccination was overall well tolerated and safe, with a low incidence of side effects, which were primarily mild. The primary meta-analysis showed a seroconversion proportion of 91% [95% CI: 84–96%] overall, with a somewhat higher proportion of 93% in patients receiving RT alone, compared to 90% in patients receiving either RT or RT combined with chemotherapy. Furthermore, immunization during RT led to a sustained increase in antibody titers, with a notable long-term persistence of IgG. Conclusions: COVID-19 vaccines demonstrate excellent safety, immunogenicity, and efficacy in patients receiving RT, who also exhibit a high willingness to be vaccinated. The outcomes observed are comparable to those in healthy controls and superior to those seen in patients receiving other cancer treatments, such as chemotherapy. The vaccination of radiation oncology patients in future pandemics or epidemics is strongly advocated even during active treatment. Full article

In the past two decades, particularly through the pandemic, the demand for real-time logistics has significantly increased. Cold chain logistics ensures specific temperature conditions for perishable goods such as food and pharmaceuticals, which is crucial for maintaining product quality, safety, and regulatory compliance. The integration of the Internet of Things (IoT) into cold chain logistics has transformed supply chain operations. The COVID-19 pandemic and the global urgency for vaccine distribution accelerated the adoption of cold chain technologies, emphasizing their role in preserving perishable goods’ integrity. IoT enables real-time monitoring, remote control, predictive analytics, and data-driven decision-making, all of which are essential for modern logistics. We conducted a bibliometric analysis of 50 publications from 1997 to 2024 to examine IoT’s role in cold chain management. Through co-occurrence and co-citation network analysis, core themes, influential works, and major contributors were identified. Thematic mapping highlighted the importance of temperature monitoring, logistics optimization, and risk management. Additionally, the transition from conventional logistics practices to IoT-driven methodologies was investigated in cold chain operations. The findings of this study provide a basis for understanding the structural properties of co-citation and co-occurrence networks in cold chain logistics and the evolving landscape of cold chain technology, and its impact on logistics, emphasizing the importance of intelligent, reliable, and sustainable cold chain systems to meet the growing demands in global supply chains. Full article