Search Results (2,268)

Recoding strategies have emerged as a promising approach for developing safer and more effective vaccines by altering the genetic structure of microorganisms, such as viruses, without changing their proteins. This method enhances vaccine safety and efficacy while minimizing the risk of reversion to virulence. Recoding enhances the frequency of CpG dinucleotides, which in turn activates immune responses and ensures a strong attenuation of the pathogens. Recent advancements highlight synonymous recoding’s potential, offering improved genetic stability and immunogenicity compared to traditional methods. Live vaccines attenuated using classical methods pose a risk of reversion to virulence and can be time-consuming to produce. Synonymous recoding, involving numerous codon alterations, boosts safety and vaccine stability. One challenge is balancing attenuation with yield; however, innovations like Zinc-finger antiviral protein (ZAP) knockout cell lines can enhance vaccine production. Beyond viral vaccines, recoding can apply to bacterial vaccines, as exemplified by modified Escherichia coli and Streptococcus pneumoniae strains, which show reduced virulence. Despite promising results, challenges like ensuring genetic stability, high yield, and regulatory approval remain. Briefly, ongoing research aims to harness these innovations for comprehensive improvements in vaccine design and deployment. In this commentary, we sought to further engage the community’s interest in this elegant approach by briefly highlighting its main advantages, disadvantages, and future prospects. Full article

After four decades of intensive research, traditional vaccination strategies for HIV-1 remain ineffective due to HIV-1′s extraordinary genetic diversity and complex immune evasion mechanisms. Cytomegaloviruses (CMV) have emerged as a novel type of vaccine vector with unique advantages due to CMV persistence and immunogenicity. Rhesus macaques vaccinated with molecular clone 68-1 of RhCMV (RhCMV68-1) engineered to express simian immunodeficiency virus (SIV) immunogens elicited an unconventional major histocompatibility complex class Ib allele E (MHC-E)-restricted CD8⁺ T-cell response, which consistently protected over half of the animals against a highly pathogenic SIV challenge. The RhCMV68-1.SIV-induced responses mediated a post-infection replication arrest of the challenge virus and eventually cleared it from the body. These observations in rhesus macaques opened a possibility that MHC-E-restricted CD8⁺ T-cells could achieve similar control of HIV-1 in humans. The potentially game-changing advantage of the human CMV (HCMV)-based vaccines is that they would induce protective CD8⁺ T-cells persisting at the sites of entry that would be insensitive to HIV-1 evasion. In the RhCMV68-1-protected rhesus macaques, MHC-E molecules and their peptide cargo utilise complex regulatory mechanisms and unique transport patterns, and researchers study these to guide human vaccine development. However, CMVs are highly species-adapted viruses and it is yet to be shown whether the success of RhCMV68-1 can be translated into an HCMV ortholog for humans. Despite some safety concerns regarding using HCMV as a vaccine vector in humans, there is a vision of immune programming of HCMV to induce pathogen-tailored CD8⁺ T-cells effective against HIV-1 and other life-threatening diseases. Full article

During the last 100 years, vaccine development has evolved from an empirical approach to one of the more rational vaccine designs where the careful selection of antigens and adjuvants is key to the desired efficacy for challenging pathogens and/or challenging populations. To improve immunogenicity while maintaining a favorable reactogenicity and safety profile, modern vaccine design must consider factors beyond the choice of target antigen alone. With new vaccine technologies currently emerging, it will be possible to custom-design vaccines for optimal efficacy in groups of people with different responses to vaccination. It should be noted that after a fairly long period of overwhelming dominance of papers devoted to subunit plague vaccines, materials devoted to the development of live plague vaccines have increasingly been published. In this review, we present our opinion on reasonable tactics for the development and application of live, safe, and protective human plague vaccines causing an enhanced duration of protection and breadth of action against various virulent strains in vaccination studies representing different ages, genders, and nucleotide polymorphisms of the genes responsible for immune response. Full article

Background: Although mRNA vaccines encapsulated in lipid nanoparticles (LNPs) have demonstrated a safety profile with minimal serious adverse events in clinical trials, there is opportunity to further reduce mRNA reactogenicity. The development of naked mRNA vaccines could improve vaccine tolerability. Naked nucleic acid delivery using the jet injection method may be a solution. Methods: In the first part of the study, the optimal conditions providing low traumatization and high expression of the model mRNA-GFP molecule in the tissues of laboratory animals were determined. Then, we used the selected protocol to immunize BALB/c mice with mRNA-RBD encoding the SARS-CoV-2 receptor-binding domain (RBD). It was demonstrated that mice vaccinated with naked mRNA-RBD developed a high level of specific antibodies with virus-neutralizing activity. The vaccine also induced a strong RBD-specific T-cell response and reduced the viral load in the lungs of the animals after infection with the SARS-CoV-2 virus. The level of immune response in mice immunized with mRNA-RBD using a spring-loaded jet injector was comparable to that in animals immunized with mRNA-RBD encapsulated in LNPs. Results: In this study, the efficacy of an inexpensive, simple, and safe method of mRNA delivery using a spring-loaded jet injector was evaluated and validated. Conclusions: Our findings suggest that the jet injection method may be a possible alternative to LNPs for delivering mRNA vaccines against SARS-CoV-2 infection. Full article

Background/Objectives: Rotavirus (RV) is the primary cause of gastroenteritis in children worldwide, contributing significantly to morbidity and mortality, particularly among children under five years of age. The introduction of Rotavirus vaccines (RVV) has markedly reduced RV-related childhood deaths, especially in Europe, where substantial reductions in hospitalizations and disease prevalence have been observed. Despite these advances, RVV uptake in Italy remains below the desired targets, with notable regional disparities. In Sicily, vaccination rates have fluctuated, with current coverage failing to meet national goals. Safety concerns and insufficient parental awareness are major barriers to RVV acceptance. Methods: This case-control study was conducted in Southern Italy to identify factors influencing parental acceptance of RVV. Data were collected from parents using a structured questionnaire that assessed socio-demographic factors, vaccine knowledge, and attitudes based on the Health Belief Model (HBM). Results: Overall, 226 parents were enrolled. Higher perceived benefit of RVV was significantly associated with increased vaccine adherence (Odds Ratio = 13.65; 95% Confidence Interval = 6.88–27.09; p < 0.001). Conclusions: These results highlight the need for targeted interventions to improve vaccine coverage and address regional and socio-economic barriers to RVV acceptance. Furthermore, tailored educational campaigns and univocal information from healthcare providers could play pivotal roles in achieving higher vaccine uptake. Full article

Background: During the COVID-19 pandemic, migrant populations remained under-immunized due to limited access to health care, language barriers, and vaccine hesitancy. The USAID-funded MOMENTUM Routine Immunization Transformation and Equity project supported the government in collaborating with various local health and non-health partners to identify and vaccinate migrants. This case study examines the roles of project partners and the strategies each entity implemented to increase COVID-19 vaccine uptake among migrants, as well as the perceptions regarding the effectiveness of these strategies. Methods: We designed a qualitative explanatory case study guided by the Behavioral and Social Drivers framework and RE-AIM implementation science frameworks. We conducted 31 focus group discussions and 50 in-depth interviews with migrants, project partners, community leaders, and government stakeholders in Tamil Nadu and Punjab. Results: In both states, partnerships with health departments, private employers, and community-based organizations were essential for identifying and vaccinating un- and under-vaccinated migrant groups. In Tamil Nadu, collaboration with the Department of Labor and mobile medical units facilitated vaccination camps at construction sites. In Punjab, religious institutions organized sessions at places of worship, and the Border Security Force enabled health workers to reach migrants living near the border. In both states, key strategies—involving influencers to discuss the importance of vaccine safety and value, bringing vaccination services to migrants’ workplaces and homes at flexible times and mandating workplace vaccination to encourage vaccination—shifted perceptions towards vaccination and increased vaccine uptake among migrants. Conclusions: The strategies and partnerships identified in this study highlight the broader implications for future public health interventions, demonstrating that collaboration with the private sector and faith-based organizations can enhance routine immunization efforts, particularly when localized to organizations that understand community needs and can address specific barriers and motivators. Full article

Pertussis, or whooping cough, is a highly contagious respiratory infection caused by the Gram-negative bacterium Bordetella pertussis. Although traditionally associated with children, pertussis is increasingly prevalent among adults, particularly those with comorbidities or weakened immune systems, where it can lead to severe complications. Diagnosing pertussis in adults can be challenging due to its nonspecific symptoms, underreporting, and the limited sensitivity of available diagnostic tests. While treatment with macrolides is generally effective, it may not significantly alter the clinical course of the disease, and growing concerns about macrolide resistance are emerging. Vaccination remains the cornerstone of prevention, offering proven immunogenicity, efficacy, and safety. However, vaccination uptake remains low, partly due to limited patient awareness and insufficient prioritization by healthcare professionals. This review aims to provide clinicians with critical insights into pertussis epidemiology, vaccination strategies, and the latest guideline recommendations, empowering them to engage in meaningful discussions with adult patients and advocate for increased vaccination to combat this often-overlooked infection. Full article

Background/Objectives Bacterial ghosts (BGs), non-living empty envelopes of bacteria, are produced either through genetic engineering or chemical treatment of bacteria, retaining the shape of their parent cells. BGs are considered vaccine candidates, promising delivery systems, and vaccine adjuvants. The practical use of BGs in vaccine development for humans is limited because of concerns about the preservation of viable bacteria in BGs. Methods: To increase the efficiency of Klebsiella pneumoniae BG formation and, accordingly, to ensure maximum killing of bacteria, we exploited previously designed plasmids with the lysis gene E from bacteriophage φX174 or with holin–endolysin systems of λ or L-413C phages. Previously, this kit made it possible to generate bacterial cells of Yersinia pestis with varying degrees of hydrolysis and variable protective activity. Results: In the current study, we showed that co-expression of the holin and endolysin genes from the L-413C phage elicited more rapid and efficient K. pneumoniae lysis than lysis mediated by only single gene E or the low functioning holin–endolysin system of λ phage. The introduction of alternative lysing factors into K. pneumoniae cells instead of the E protein leads to the loss of the murein skeleton. The resulting frameless cell envelops are more reminiscent of bacterial sacs or bacterial skins than BGs. Although such structures are less naive than classical bacterial ghosts, they provide effective protection against infection by a hypervirulent strain of K. pneumoniae and can be recommended as candidate vaccines. For our vaccine candidate generated using the O1:K2 hypervirulent K. pneumoniae strain, both safety and immunogenicity aspects were evaluated. Humoral and cellular immune responses were significantly increased in mice that were intraperitoneally immunized compared with subcutaneously vaccinated animals (p < 0.05). Conclusions: Therefore, this study presents novel perspectives for future research on K. pneumoniae ghost vaccines. Full article

Background/Objectives: Rapid cycle analysis (RCA) is an established and efficient methodology that has been traditionally utilized by United States health authorities to monitor post-approval vaccine safety. Initially developed in the Vaccine Safety Datalink (VSD) in early 2000s, RCA has evolved into a valuable approach for timely post-approval signal detection. Due to the availability of additional near real-time data sources and enhanced analytic approaches, the use of RCA has expanded. This narrative review provides an in-depth assessment of studies that utilized RCA for safety surveillance to detect and evaluate safety signals in post-approval vaccine monitoring. Methods: Embase and Medline were searched on 8 August 2024 to identify post-approval non-interventional vaccine safety studies using RCA or other near real-time surveillance methods published from 1 January 2018 to 31 July 2024. Data on study characteristics (e.g., study population, data source, outcomes) and RCA methodological characteristics (e.g., type of comparator, sequential testing method, confounding control method) were extracted from the eligible RCA studies. Results: Of 1128 articles screened, 18 RCA vaccine safety studies were included, of which 17 (94.4%) were conducted in the United States (US). Twelve (67%) aimed at signal detection and six (33%) conducted further signal evaluation. Over 60% examined COVID-19 vaccine safety, with half using VSD. Over 80% conducted the RCA weekly or monthly and about 78% of the studies used a database-specific historical comparator group. Conclusions: This review indicates that most of the published articles on the application of the RCA methodology in vaccine safety studies are based on research conducted in the US. With increasing availability of near real-time data sources and advanced analytic methods capabilities, RCA is expected to be more widely deployed as an active surveillance tool to complement traditional pharmacovigilance. Future studies should explore the extension of vaccine RCA methodology for non-vaccine medicinal products. Full article

Background: China has a high incidence rate of varicella yet a low coverage rate of the varicella vaccine (VarV), with safety concerns being a leading cause of the lack of vaccination willingness. This study aimed to describe VarV-related adverse events following immunization (AEFIs) and analyze their characteristics in Zhejiang, China, 2020–2022. Methods: VarV-related AEFIs in Zhejiang Province from 1 January 2020 to 31 December 2022 were collected through the Chinese National AEFI Information System (CNAEFIS) for a descriptive epidemiological analysis. Results: From 2020 to 2022, a total of 1477 VarV-related AEFI cases were reported (incidence rate: 34.79/100,000). The three most frequently reported clinical symptoms of common adverse reactions were fever, redness, and induration at the vaccination site. The distribution of VarV-related AEFIs varied significantly by age, dose, severity, and season. VarV-related AEFIs were more likely to be non-severe adverse events that occurred in the summer and winter seasons following the first dose of vaccine and among those under 3 years old. The top three regions with the highest incidence rates were Lishui City (59.53/100,000), Quzhou City (41.05/100,000), and Jinhua City (40.43/100,000). Most of the cases achieved full recovery without treatment (96.21%), and the rest were successfully treated without any sequelae. Conclusions: VarV demonstrates a safe profile in Zhejiang Province. Most VarV-related AEFIs are common reactions without requiring treatment, and the rates of rare and severe AEFIs remain low. Consistent monitoring, investigation, and diagnosis are needed to guide future VarV research and vaccination strategy adjustment. Our findings call for more policy changes, such as integrating VarV into China’s National Immunization Program and conducting more trials to evaluate the safety and effectiveness of VarV. Full article

Background: The emergence of more than 40 new infectious diseases since the 1980s has emerged as a serious global health concern, many of which are zoonotic. In response, many international organizations, including the US Centers for Disease Control and Prevention (CDC), the World Health Organization (WHO), and the European Center for Disease Prevention and Control (ECDC), have developed strategies to combat these health threats. The need for rapid vaccine development has been highlighted by Coronavirus disease 2019 (COVID-19), and mRNA technology has shown promise as a platform. While the acceleration of vaccine development has been successful, concerns have been raised about the technical limits, safety, supply, and distribution of vaccines. Objective: This study analyzes the status of vaccine platform development in global pandemics and explores ways to respond to future pandemic crises through an overview of the roles of international organizations and their support programs. It examines the key roles and partnerships of international organizations such as the World Health Organization (WHO), vaccine research and development expertise of the Coalition for Epidemic Preparedness Innovations (CEPI), control of the vaccine supply chain and distribution by the Global Alliance for Vaccines and Immunization (GAVI), and technology transfer capabilities of the International Vaccine Institute (IVI) in supporting the development, production, and supply of vaccine platform technologies for pandemic priority diseases announced by WHO and CEPI and analyzes their vaccine support programs and policies to identify effective ways to rapidly respond to future pandemics caused by emerging infectious diseases. Methods: This study focused on vaccine platform technology and the key roles of international organizations in the pandemic crisis. Literature data on vaccine platform development was collected, compared, and analyzed through national and international literature data search sites, referring to articles, journals, research reports, publications, books, guidelines, clinical trial data, and related reports. In addition, the websites of international vaccine support organizations, such as WHO, CEPI, GAVI, and IVI, were used to examine vaccine support projects, initiatives, and collaborations through literature reviews and case study methods. Results: The COVID-19 pandemic brought focus on the necessity for developing innovative vaccine platforms. Despite initial concerns, the swift integration of cutting-edge development technologies, mass production capabilities, and global collaboration have made messenger RNA (mRNA) vaccines a game-changing technology. As a result of the successful application of novel vaccine platforms, it is important to address the remaining challenges, including technical limits, safety concerns, and equitable global distribution. To achieve this, it is essential to review the regulatory, policy, and support initiatives that have been implemented in response to the COVID-19 pandemic, with particular emphasis on the key stages of vaccine development, production, and distribution, to prepare for future pandemics. An analysis of the status of vaccine development for priority pandemic diseases implies the need for balanced vaccine platform development. Also, international organizations such as WHO, CEPI, GAVI, and IVI play key roles in pandemic preparedness and the development and distribution of preventive vaccines. These organizations collaborated to improve accessibility to vaccines, strengthen the global response to infectious diseases, and address global health issues. The COVID-19 pandemic response demonstrates how the synergistic collaboration of WHO’s standardized guidelines, CEPI’s vaccine research and development expertise, GAVI’s control of the vaccine supply chain and distribution, and IVI’s technology transfer capabilities can be united to create a successful process for vaccine development and distribution. Conclusions: In preparation for future pandemics, a balanced vaccine platform development is essential. It should include a balanced investment in both novel technologies such as mRNA and viral vector-based vaccines and traditional platforms. The goal is to develop vaccine platform technologies that can be applied to emerging infectious diseases efficiently and increase manufacturing and distribution capabilities for future pandemics. Moreover, international vaccine support organizations should play key roles in setting the direction of global networking and preparing for international vaccine support programs to address the limitations of previous pandemic responses. As a result, by transforming future pandemic threats from unpredictable crises to surmountable challenges, it is expected to strengthen global health systems and reduce the social and economic burden of emerging infectious diseases in the long term. Full article

This systematic review evaluated the effectiveness and side effects of various COVID-19 vaccines, with a focus on Trinidad and Tobago. The Pfizer-BioNTech and Moderna vaccines demonstrated the highest efficacy, particularly against COVID-19 variants, while Janssen and Sinopharm were comparatively less effective. mRNA vaccines, such as Pfizer-BioNTech and Oxford-AstraZeneca, were associated with more frequent and severe side effects, including soreness, fever, and cardiovascular issues. The review also identified significant gaps in the current scientific literature regarding COVID-19 vaccination issues in Trinidad and Tobago. These gaps highlight the need for comprehensive research to address vaccination challenges, including public health communication, equitable access, and local perceptions of vaccine safety. This analysis provides a foundation for developing targeted strategies to improve vaccine effectiveness in the region. Full article

Objectives: Vaccination against SARS-CoV-2 has been vital in alleviating the spread of the recent pandemic. We aimed to estimate the frequency and type of adverse events related to SARS-CoV-2 vaccine in patients with lupus nephritis (LN), and assess its impact, if any, on the risk of subsequent reactivation of nephritis. Methods: This was a retrospective, multicenter study which included patients with biopsy-proven LN, who had received at least one vaccine dose. Patients who ended up with end-stage kidney disease (ESKD) prior to vaccination or were diagnosed with LN after vaccination were excluded. Adverse events, systemic or local, COVID-19 outcomes (full recovery, death, or long COVID-19), outcome of LN (remission, refractory disease, relapse, ESKD or death), demographics, laboratory measurements, and immunosuppressive regimens were recorded. Results: Sixty-seven patients were included. The median age was 33 (20–46) years. Induction therapy for LN was administered to 92.5% of patients and 74.6% received maintenance therapy. Of these, 94.02% were in remission at vaccination. The BNT162b2 mRNA vaccine was administered in 97.01% of cases, with mild systemic adverse symptoms in 28.35% (myalgias 17.91%, headache 13.43%, arthralgias 13.43%, and fever 10.44%) and local adverse effects in 35.82% (pain 25.37%, swelling 13.43%). Overall, among patients in remission upon vaccination, two (3.17%) experienced a LN relapse within 5.75 (±0.25) months, while 75% of those with active disease at vaccination achieved remission within 21 (±2) months. Conclusions: SARS-CoV-2 vaccination appears safe for LN patients without serious adverse events occurring, and there is no significant impact in the clinical course of the disease. Full article

Background/Objectives: Lyme disease (LD) is a major public health problem in Europe and the United States, with increasing incidence and not many prevention options. Vaccine hesitancy might be a significant barrier to successful vaccination campaigns having in mind previous vaccine development failures. This study aimed to evaluate the public’s perception of LD vaccination in Poland, assess willingness to vaccinate, and identify factors influencing vaccination attitudes. Methods: A cross-sectional survey was conducted among parents of children hospitalized at the University Children’s Hospital in Bialystok, Poland. The survey consisted of 29 questions regarding demographics, LD knowledge, vaccine attitudes, and perceived risks. Data were collected between January and December 2023 and analyzed using descriptive and inferential statistics to identify predictors of respondents’ positive vaccination attitudes. Results: A total of 503 valid responses were analyzed. Most respondents (72.4%) showed positive attitudes towards vaccination, while 18.5% were neutral and 9.1% were negative. Trust in health experts emerged as an important predictor of vaccination acceptance (OR 22.84; p < 0.001). More than 80% of participants recognized an LD vaccine as necessary, and 64.21% believed it would reduce their concerns about LD. Willingness to vaccinate was influenced by general positive vaccine attitudes, recognized danger of LD, and belief in the vaccine’s ability to ease fears. Notably, 40.8% of respondents were uncertain about vaccine risks, with this group tending to be younger, less educated, and expressing lower trust in medical professionals. Conclusions: Public perception of LD in Poland indicates a high acceptance of a potential LD vaccine. Still, addressing vaccine hesitancy remains critical, particularly among undecided or neutral respondents. Building trust in healthcare professionals and addressing safety worries are important to increasing future LD vaccine use. Full article

Background/Objectives: Influenza vaccination is the main method for preventing influenza. The objectives of this study are to evaluate the opinions of families on influenza vaccination and to determine the acceptance of influenza vaccination as a routine vaccine in children under 5 years of age. Methods: The method used was a descriptive cross-sectional study based on an ad-hoc survey. Between October 2023 and January 2024, an online survey was conducted among families with children between 6 months and 14 years of age attending paediatric consultations at a health centre. Results: A total of 388 families were surveyed. Out of these, 22.68% reported having ever vaccinated their children against influenza. The main reason for having them vaccinated was having received the recommendation from the paediatrician (68.18%). While 53.61% agreed with routine influenza vaccination, 53.09% did not intend to vaccinate their children against influenza in the 2023/24 period. The reasons for not vaccinating in 2023/24 were unawareness of the disease (29.41%), fear of unwanted effects of vaccination (27.94%) and lack of information about vaccination (19.61%). The reasons for vaccination in 2023/24 were protection of the child (81.87%), recommendation by the paediatrician (43.41%) and protection of the general population and susceptible persons (20.33%). Conclusions: Routine influenza vaccination is accepted by half of the parents. A lack of risk perception of the disease, concern about vaccine safety and lack of information are the main reasons for not vaccinating. It is essential to follow the health professionals’ recommendation to vaccinate. Full article