Hand-foot-and-mouth disease (HFMD) remains a significant public health concern for children. Enterovirus A71 (EV71) and coxsackievirus A16 (CVA16) have been the main causes of HFMD; however, CVA10 and CVA6 have become mo...Hand-foot-and-mouth disease (HFMD) remains a significant public health concern for children. Enterovirus A71 (EV71) and coxsackievirus A16 (CVA16) have been the main causes of HFMD; however, CVA10 and CVA6 have become more prevalent in recent years. A universally effective vaccine that covers all four major enteroviruses is of importance. In this study, we developed and assessed the immunogenicity of two differently designed tetravalent DNA-based HFMD vaccines in a murine model. The new immunogen, EVCVAme, was designed with a string of reported B-cell epitopes from the four enteroviruses, while VP1EVCVAme was designed with the full-length EV71 VP1 fused with a string of reported B-cell epitopes from the four enteroviruses. In silico analysis indicated favorable structural and functional features of both immunogens. The immunization of mice with DNA vaccines expressing those two immunogens elicited HFMD-specific antibody responses, but the IgG levels were lower compared to the immunization with our previous tetravalent vaccine pVAX1.VP1me. Interestingly, only the vaccines containing full-length VP1 elicited detectable enterovirus-specific CD8 T cell response. Intracellular cytokine staining revealed polyfunctional vaccine-activated CD8 T cells upon restimulation with mixtures of the B-cell epitope peptides, indicating a dual role of these B-cell epitopes. Notably, co-administration of two vaccines neither improved the breadth nor magnitude of the immune responses. B-cell epitope mapping revealed different patterns of responding epitopes across the vaccine groups. Importantly, pVAX1.EVCVAme elicited antibodies that cover all four enteroviruses. This study offers valuable insights and important information for the improved design of a next-generation tetravalent vaccine for HFMD.
BACKGROUND: Autologous tumor vaccines have been investigated as immunotherapeutic strategies in veterinary oncology and may represent relevant translational models for comparative cancer immunotherapy. However, reported...BACKGROUND: Autologous tumor vaccines have been investigated as immunotherapeutic strategies in veterinary oncology and may represent relevant translational models for comparative cancer immunotherapy. However, reported clinical outcomes in dogs remain heterogeneous. OBJECTIVE: To evaluate the safety, clinical outcomes, and immunological assessment methods of autologous tumor vaccines in dogs. METHODS: A systematic review of PubMed, Web of Science, and Scopus identified 24 eligible studies evaluating autologous tumor vaccines in dogs. Vaccine platforms, safety data, clinical outcomes, and immunological assessments were analyzed descriptively. Exploratory pooled hazard ratio analyses were performed using random-effects models when applicable. RESULTS: Autologous tumor vaccines were generally reported as well tolerated, with predominantly mild and transient adverse events. Clinical outcomes varied substantially across tumor types and study designs. Canine lymphoma represented the setting with the greatest concentration of evidence, including the few randomized and controlled studies identified. Several lymphoma studies reported longer time to progression and lymphoma-specific survival in vaccinated dogs compared with chemotherapy-alone or historical comparator groups, although findings were not consistent across all studies. Exploratory pooled analyses suggested a trend toward reduced risk of progression and lymphoma-related mortality in immunotherapy-treated dogs; however, these findings should be interpreted cautiously given the limited number of studies and methodological heterogeneity. In solid tumors, outcomes were more variable and evidence remained predominantly exploratory. CONCLUSIONS: Current evidence suggests that autologous tumor vaccines in dogs are generally feasible and well tolerated, although methodological limitations restrict interpretation of therapeutic efficacy. Further prospective and standardized studies are needed to clarify their role in veterinary oncology and comparative cancer immunotherapy.
Human papillomavirus (HPV) is the most common sexually transmitted infection among people ages 15-24 years in the U.S. However, many individuals remain unvaccinated against HPV. Recommendations from friends and family ha...Human papillomavirus (HPV) is the most common sexually transmitted infection among people ages 15-24 years in the U.S. However, many individuals remain unvaccinated against HPV. Recommendations from friends and family have been shown to improve vaccine uptake and should be encouraged. This study aimed to determine if the provision of vaccine-related information would change the likelihood of recommending the HPV vaccine to their peers. Furthermore, we examined characteristics associated with a positive change. Participants were recruited at two no-cost vaccine clinics on a university campus in September and October 2024. Through a one-time, voluntary, online survey, participants were asked how likely they were to recommend the HPV vaccine to a family or friend on a scale from 1 (very unlikely) to 5 (very likely). This question was repeated after they were provided with a list of diseases that are prevented by the HPV vaccine. We conducted dependent samples t-tests to determine if there was a change in recommendation scores before and after information provision. We also conducted bivariate (chi-square and independent t-tests) and multivariable (logistic regression) analyses to examine factors associated with a positive change versus no/negative change. The final sample (n = 556) were majority White (n = 310, 55.8%), female (n = 331, 59.5%), and college students (n = 480, 86.5%). The average post-information provision (Mean = 4.21; SD = 0.95) recommendation score was significantly higher than the pre-information provision (Mean = 3.87; SD = 1.031) recommendation score (t = -11.37; p < 0.001). In multivariable logistic regression analyses, there was a statistically significant positive change in recommendation score with younger age (aOR = 0.98, 95% CI = 0.95-1.00) and lower vaccine confidence (aOR = 0.50, 95%CI = 0.36-0.68). This indicates that targeted interventions to improve awareness of diseases prevented by the HPV vaccine could be particularly effective in populations that are younger or have lower vaccine confidence.
OBJECTIVES: Confidence in scientific, manufacturing, and regulatory bodies is a key determinant of vaccine acceptance, particularly for locally produced vaccines. This study examined how such trust influences acceptance...OBJECTIVES: Confidence in scientific, manufacturing, and regulatory bodies is a key determinant of vaccine acceptance, particularly for locally produced vaccines. This study examined how such trust influences acceptance of a hypothetical locally manufactured mRNA vaccine in Malaysia. METHODS: A cross-sectional online survey of 2028 Malaysian adults assessed confidence in local scientists, manufacturers, regulatory authorities, and international regulatory bodies. Partial least squares structural equation modeling (PLS-SEM) was used to identify predictors of acceptance. RESULTS: Of respondents, 55.8% indicated they would probably accept the vaccine, while 40.1% would definitely accept it. Only 4.1% reported they would not accept the vaccine. PLS-SEM analysis revealed that confidence in local vaccine regulatory authorities was the strongest predictor of public acceptance of locally-produced mRNA vaccines (β = 0.183, p < 0.0001), followed by confidence in local vaccine manufacturers (β = 0.133, p < 0.0001), the local scientific community (β = 0.108, p = 0.001), and lastly, confidence in international regulatory authorities (β = 0.078, p = 0.016). CONCLUSIONS: The study concludes that confidence in national regulatory authorities, followed by trust in local manufacturers and the scientific community, plays a central role in acceptance of locally produced vaccines, surpassing trust in international authorities. Public acceptance of locally produced vaccines is driven mainly by trust in national regulators, followed by manufacturers, the scientific community, and international regulators. Enhancing acceptance requires coordinated action across sectors, with strong trust in national regulators underscoring the need for halal certification and other cultural considerations in Muslim-majority settings.
Spila-Alegiani S, Massari M, Cutillo M
… +23 more, Menniti-Ippolito F, Da Cas R, Mayer F, Marano G, Belleudi V, Addis A, Desiderio V, Mores N, Lopes S, Balducci M, Ejlli L, Del Zotto S, Clagnan E, Samez S, Zappetti C, Rossi P, Sapigni E, Puccini A, Villa M, Visigalli C, Trifirò G, Luxi N, Morciano C
INTRODUCTION: This study evaluated the safety of influenza vaccines in a large and representative population during the 2021/2022 campaign in Italy using a Self-Controlled Case Series (SCCS) design using regional health...INTRODUCTION: This study evaluated the safety of influenza vaccines in a large and representative population during the 2021/2022 campaign in Italy using a Self-Controlled Case Series (SCCS) design using regional health data registries. METHODS: This multiregional study used healthcare data to assess pre-specified potential adverse outcomes after flu vaccination during the 2021/2022 season. Participants were individuals aged 6 months or older, vaccinated or not, admitted to emergency care or hospital for at least one of the incident outcomes of interest. Risk periods were specifically defined for each outcome and compared to reference periods. The Self-Controlled Case Series design modified for event-dependent exposures was used, estimating relative incidences and excess cases by age, sex, dose, and adjusting for calendar time. RESULTS: No increased risks were observed for most of the study outcomes. An increased risk of thrombocytopenia (RI = 1.90; 95% CI: 1.00-3.61) and optic nerve neuritis (RI = 5.22; 95% CI: 1.31-20.79) was detected within 42 days after vaccination in individuals under 60 years. Sensitivity and ancillary analyses supported these findings. CONCLUSIONS: These findings confirm the overall safety of influenza vaccines during the 2021/2022 campaign, with no evidence of increased risk for most of the pre-specified adverse outcomes. The increased risks observed for thrombocytopenia and optic neuritis need further research.
OBJECTIVE: To assess end-of-season coverage with influenza, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap), and COVID-19 vaccines among pregnant women, and respiratory syncytial virus (RSV) imm...OBJECTIVE: To assess end-of-season coverage with influenza, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap), and COVID-19 vaccines among pregnant women, and respiratory syncytial virus (RSV) immunization among pregnant women and their infants, during the 2024-25 respiratory illness season. METHODS: Data from an Internet panel survey conducted during March 26-May 8, 2025, were analyzed. The study included 2738 currently and recently pregnant women; analysis of each immunization product was restricted to a subsample of participants eligible for the specific product (influenza: 1788; Tdap: 885; COVID-19: 2125; maternal RSV: 721; nirsevimab: 1416). Coverage was assessed for individual vaccines, along with demographic characteristics, provider recommendation for immunization, and attitudes, including perceptions on safety and effectiveness of vaccines. Differences in vaccination coverage between groups were assessed using t-tests. RESULTS: Among eligible participants, 51.0% reported receiving influenza vaccine before or during pregnancy, 52.6% reported receiving Tdap vaccine during pregnancy, 32.3% reported receiving the 2024-25 COVID-19 vaccine before or during pregnancy, and 49.3% reported receiving an RSV vaccine during pregnancy. Among 1416 women with eligible infants, 62.2% reported their infant received nirsevimab; overall, 70.4% of infants were protected by maternal RSV vaccine, nirsevimab, or both. Vaccination coverage was higher among women with a provider recommendation compared to those without for influenza (65.6% vs. 12.2%), Tdap (69.5% vs. 2.9%), and COVID-19 (56.4% vs. 4.4%) vaccines. Prevalence of provider recommendation for Tdap vaccination was lower among non-Hispanic Black (66.4%) and Hispanic women (60.1%) compared with non-Hispanic White women (83.2%). Women reporting being very/somewhat hesitant about a given vaccine were less likely than non-hesitant women to have received that vaccine. CONCLUSION: Provider recommendation and vaccine hesitancy were associated with maternal vaccine uptake. Because providers have been found to be trusted information sources for patients, efforts supporting informative vaccine conversations between providers and pregnant women could help increase the proportion of pregnant women and infants protected against severe respiratory illnesses.
BACKGROUND: The COVID-19 pandemic drove the implementation of vaccine mandates to protect spaces and/or increase vaccine uptake, though their design, timing, and scope varied across jurisdictions. This study examines the...BACKGROUND: The COVID-19 pandemic drove the implementation of vaccine mandates to protect spaces and/or increase vaccine uptake, though their design, timing, and scope varied across jurisdictions. This study examines the associations of vaccine mandate announcements and removals with COVID-19 vaccine uptake in France, Italy, and California (USA). METHODS: We employed interrupted time series (ITS) analysis using aggregated data from Our World in Data and the Oxford COVID-19 Government Response Tracker. The primary outcomes were the weekly number of first and booster doses per 100,000 people. We estimated changes in the rate and trend of vaccine uptake following policy announcements and removals, adjusting for COVID-19 cases, deaths, and temporal autocorrelation to account for other influencing factors. FINDINGS: Initial mandate announcements were associated with immediate increases in vaccine uptake: 113% (95% CI: 63 to 178%) in Italy, 195% (95% CI: 113 to 308%) in France, and 32% (95% CI: 16 to 51%) in California. However, these associations attenuated in more fully adjusted models, especially in France, where the initial association was no longer statistically significant after controlling for epidemiological conditions and temporal autocorrelation. Mandate removals were more consistently associated with declines in booster uptake in Italy and France, including declines of 62% (95% CI: -74 to -45%) and 70% (95% CI: -79 to -57%), respectively, while partial removal in California coincided with increased booster uptake. CONCLUSION: Vaccine mandate announcements were associated with short-term increases in vaccine uptake during key periods of the pandemic. Their removal was often associated with a slowing in uptake, highlighting the need for coordinated communication strategies to sustain coverage. Future policy responses should consider timing, mandate design, and transition planning in contexts where such policies are used.
Toxoplasmosis represents a significant global health concern due to the limited availability of safe and effective vaccines and drugs. mRNA technology offers a promising approach for toxoplasmosis vaccine development, co...Toxoplasmosis represents a significant global health concern due to the limited availability of safe and effective vaccines and drugs. mRNA technology offers a promising approach for toxoplasmosis vaccine development, combining effectiveness with enhanced safety features. Unlike DNA vaccines, mRNA vaccines remain exclusively in the cytoplasm, eliminating the risk of genomic integration and malignant cell transformation. We designed an RNA-based vaccine encoding the T. gondii SAG1 gene and validated its protein expression in vitro using Western blotting and indirect fluorescent antibody testing (IFAT). Following intramuscular administration in BALB/c mice, we evaluated the resulting protective immune responses. Mice immunized with SAG1 mRNA exhibited robust immune responses involving both cellular and humoral immunity. Immunological analysis revealed elevated titers of T. gondii-specific IgG antibodies (P < 0.01), with predominant representation of the IgG2a subclass relative to IgG1. Cytokine analysis revealed elevation of IFN-γ and IL-4 levels (P < 0.05), indicating a mixed Th1/Th2 immune response with predominant Th1 activity. Following SAG1 mRNA immunization, there was a marked increase in the expression levels of three key inflammatory mediators: tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6) (P < 0.01). No significant inflammatory or morphological changes were detected in hepatocytes post-vaccination. This immunological response was associated with significant alterations in mortality rates and parasite burdens in vaccinated mice (P < 0.001). Most importantly, mice vaccinated with SAG1 mRNA showed significantly enhanced protection against acute infection compared to those receiving the SAG1 DNA vaccine. Our findings suggest that the use of an mRNA-based platform for SAG1 delivery may provide a feasible strategy for vaccine development against T. gondii, supporting further investigation.
While conducting probabilistic surveys is the gold standard for assessing vaccine coverage, implementing these surveys poses challenges for global health. There is a need for more convenient option that is more affordabl...While conducting probabilistic surveys is the gold standard for assessing vaccine coverage, implementing these surveys poses challenges for global health. There is a need for more convenient option that is more affordable and practical. Motivated by childhood vaccine monitoring programs in rural areas of Chad and Niger, we conducted a simulation study to evaluate calibration-weighted design-based and logistic regression-based imputation estimators of the finite-population proportion of MCV1 coverage. These estimators use a hybrid approach that anchors non-probabilistic follow-up survey to probabilistic baseline census to account for selection bias. We explored varying degrees of non-ignorable selection bias (odds ratios from 1.0 to 1.5), percentage of villages sampled (25-75%), and village-level survey response rate to the follow-up survey (50-80%). Our performance metrics included bias, coverage, and proportion of simulated 95% confidence intervals falling within equivalence margins of 5% and 7.5% (equivalence tolerance). For both adjustment methods, the performance worsened with higher selection bias and lower response rate and generally improved as a larger proportion of villages was sampled. Under the worst scenario with 1.5 OR, 25% village sampled, and 50% survey response rate, both methods showed empirical biases of 2% or less, below 95% coverage, and low equivalence tolerances. In more realistic scenarios, the performance of our estimators showed lower biases and close to 95% coverage. For example, at OR ≤ 1.2, both methods showed high performance, except at the lowest village sampling and participation rates. Our simulations show that a hybrid anchoring survey approach is a feasible survey option for vaccine monitoring.
In this study, we investigated the efficacy of autologous tumor lysate vaccines derived from orthotopic and subcutaneous glioma tissues in the GL261 mouse model of glioblastoma multiforme (GBM). We prepared two types of...In this study, we investigated the efficacy of autologous tumor lysate vaccines derived from orthotopic and subcutaneous glioma tissues in the GL261 mouse model of glioblastoma multiforme (GBM). We prepared two types of lysate vaccines: intracranial tumor lysate (ITL) and subcutaneous tumor lysate (STL). The results demonstrated that ITL vaccination significantly prolonged the survival of glioma-bearing mice, enhanced the recruitment of antigen-presenting cells (APCs) to the brain, and increased the activation of CD8 T cells expressing IFN-γ compared to STL and saline controls. STL was also effective in reducing tumor growth in subcutaneous models, indicating the broader applicability of tumor lysate-based vaccines. The ITL vaccine induced a robust anti-glioma immune response by promoting Th1-type immunity, upregulating co-stimulatory molecules (CD80 and CD86), and increasing MHC-I and MHC-II expression, which contributed to enhanced antigen presentation and tumor clearance. These findings underscore the potential of autologous tumor lysate-based vaccines, particularly ITL, as promising immunotherapies for the treatment of GBM. Further investigation into the combination of tumor lysate vaccines with adjuvants and immune checkpoint inhibitors may enhance their clinical applicability and efficacy. Here, the term "vaccine" is used to describe a tumor lysate-based immunostimulatory intervention in mice. This work represents a preclinical proof-of-concept rather than a directly translatable clinical strategy.
BACKGROUND: Congenital cytomegalovirus infection (cCMVi) is a major global health problem and a leading cause of childhood hearing, visual, and intellectual disability. Development of an effective vaccine against CMV is...BACKGROUND: Congenital cytomegalovirus infection (cCMVi) is a major global health problem and a leading cause of childhood hearing, visual, and intellectual disability. Development of an effective vaccine against CMV is a high priority, and there is optimism that one will be achieved soon. Previous mathematical modelling to predict the impact of CMV vaccination in low CMV seroprevalence, high-income populations indicate that vaccinating infants could be a highly efficient strategy to prevent cCMVi, even with only a modestly effective vaccine (i.e., <50% protective against primary infection). However, whether vaccinating infants is optimal in high CMV seroprevalence settings, where rates of cCMVi are correspondingly higher, is unclear. METHODS: We adjusted our existing agent-based stochastic model to study CMV vaccine efficacy in high seroprevalence settings (reaching 90%) with Brazil as a test case. RESULTS: Our results suggest that vaccinating 12-year-old girls and women of childbearing age would have limited ability to reduce cCMVi rates in Brazil, even with a vaccine conferring complete life-long protection against CMV infection. In contrast, vaccinating infants was predicted to provide substantial long-term reductions in the number of cCMVi cases in Brazil, even if it only induced protection equivalent to natural immunity against CMV reinfection and reactivation. Further, our model predicted that if two-thirds of Brazilian infants were vaccinated, a modestly effective vaccine would reduce the number of cCMVi cases by up to 76%. CONCLUSION: Together with results from other studies, this analysis underscores that infancy is likely the optimal target age for CMV vaccination to prevent cCMVi in all populations, regardless of the CMV seroprevalence. Furthermore, our findings predict large reductions in disease due to cCMVi worldwide through attainable vaccination scenarios.
Favre G, Pfund A, Gerbier E
… +49 more, Anselem O, Balaya V, Ceccaldi PF, Chalouhi G, Ducarme G, Garabedian C, Guerby P, Mottet N, Picone O, Poncelet C, Quibel T, Sananes N, Sentilhes L, Simon J, Tran PL, Ville Y, Baud D, Blume C, Capoccia Brugger R, Farin A, Fougère Y, Fruscalzo A, Gallmann D, Haslinger C, Huber D, Martinez de Tejada B, Radan AP, Schäffer L, Todesco Bernasconi M, Vökt C, Miranda J, Nieto-Calvache AJ, Rivera-Torres LF, De Santis M, Kratochwila C, Paladini D, Tantari M, Ernst C, Mossong J, Murray J, Feuerschuette OHM, Luz AG, Surita F, Boucoiran I, Goncé A, Higgins M, Démolis R, Alexandre K, Pomar L
BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infections in infants. Two effective preventive strategies exist: maternal RSV Prefusion F vaccination during pregnancy...BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infections in infants. Two effective preventive strategies exist: maternal RSV Prefusion F vaccination during pregnancy and child immunisation with monoclonal antibodies. OBJECTIVES: To assess pregnant individuals' acceptance of, and preferences between, maternal RSV vaccination and infant monoclonal antibodies across diverse global settings after receiving standardized information on RSV risks and expected protective benefits. STUDY DESIGN: Cross-sectional study conducted between March 2024 and March 2025 among pregnant individuals recruited by convenience sampling in partner centres across eight countries (Brazil, Canada, Colombia, Spain, France, Italy, Luxembourg, and Switzerland). The primary outcome was acceptance of RSV vaccination during pregnancy, and the secondary outcome was preference between maternal RSV vaccination and infant Nirsevimab; associated factors were assessed using multivariable logistic regression, with country group included as a design-related adjustment variable. RESULTS: Among 887 participants, 675 (76.1%) reported accepting RSV vaccination during pregnancy: 96 (10.8%) were already vaccinated and 579 (65.3%) would have liked to receive it when available. Acceptance of the RSV vaccine during pregnancy differed across main study sites, ranging from 70.4% in Switzerland to 79.1% in Colombia. Factors independently associated with willingness to be vaccinated included having a child previously hospitalised in neonatal intensive care unit, uptake of other recommended vaccines during pregnancy, and perceiving a positive influence from health authorities. Most of participants (69.8%, 619/887) preferred maternal RSV vaccination over child immunisation with monoclonal antibody administration (14.5%, 129/887). Factors independently associated with vaccination preference included: having received other recommended vaccines during pregnancy, whereas history of pre-eclampsia or perception of foetal or obstetrical risk associated with this vaccine favoured preference for the monoclonal antibody. Additional motivations for preferring maternal RSV vaccination included: avoiding an extra injection for the newborn, perceived greater efficacy, and a preference for endogenous antibody-mediated protection. CONCLUSION: This multinational study demonstrates high acceptance of maternal RSV vaccination and a predominant preference for this strategy over infant immunisation. These findings highlight the importance of tailored communication addressing pregnant individuals' concerns about safety and efficacy, alongside policies that align with parental vaccination preferences to facilitate effective implementation.
Yellow fever (YF) remains a significant public health concern despite the success of the live-attenuated YF-17D vaccine. While YF-17D serves as a benchmark for durable protection, its inherent drawbacks, including cold-c...Yellow fever (YF) remains a significant public health concern despite the success of the live-attenuated YF-17D vaccine. While YF-17D serves as a benchmark for durable protection, its inherent drawbacks, including cold-chain dependence, contraindications for vulnerable populations, and rare severe adverse events, necessitate the development of safer, more deployable alternatives. The core of next-generation vaccine design lies in the systematic identification and functional validation of highly effective YFV epitopes. The robust immunogenicity of YF-17D is characterized by a polyfunctional, multilineage immune response sustained by high-quality CD8 T cells (targeting NS3 and NS4B) and neutralizing antibodies (targeting the E protein domains EDII and EDIII). Advanced analyses reveal that precise epitope selection within these proteins is the foundational principle for next-generation platforms. Rather than offering a merely historical literature recap, this review provides a critical, methodologically driven synthesis that bridges computational tools, such as immunoinformatics, molecular dynamics simulations, and systems biology, with biological validation pipelines. By establishing this 'prediction-to-proof' framework, next-generation platforms (including peptide-based, genetic, and chimeric constructs) can be rationally engineered to minimize reactogenicity while retaining the robust immunological signature defined by YF-17D. Ultimately, this approach provides an actionable blueprint to translate high-resolution immunopeptidomic data into precision tools for yellow fever control and broader flavivirus vaccine design.
VLA1553 is a live-attenuated chikungunya virus vaccine approved for active immunization, in the EU, Brazil, Canada and the UK, as a prophylactic measure for individuals travelling to or living in areas where the chikungu...VLA1553 is a live-attenuated chikungunya virus vaccine approved for active immunization, in the EU, Brazil, Canada and the UK, as a prophylactic measure for individuals travelling to or living in areas where the chikungunya virus is circulating. Due to the unpredictable epidemic occurrence of chikungunya, a 50% micro-plaque reduction neutralization test titre (μPRNT) of ≥150, was previously accepted by regulators as an immunological surrogate endpoint that is reasonably likely to predict clinical benefit. At this point in time, this phase 3b open-label, single-arm long-term focuses on antibody persistence in a subset (N = 363) of VLA1553 vaccinees from a pivotal phase 3 trial (Schneider et al., 2023) where 4115 adult participants received VLA1553 or placebo. At Year 4, 254 participants remained in follow-up with slightly more females than males. The population is predominantly White with no Hispanic or Latino background. The seroresponse rate was 94.5% (240/254, 95% CI 90.9% to 97.0%). The Day 29 GMT for the long-term follow-up cohort was 3542, and remained high with 1056 at Year 1, 785 at Year 2, 737 at Year 3 and 589 at Year 4, considerably exceeding the seroresponse threshold of 150. In adults aged ≥65 years, antibody persistence was similar to younger adults throughout the follow-up. Single dose vaccination with our live-attenuated chikungunya virus vaccine VLA1553 resulted in persistent neutralizing antibody titers well above the defined seroresponse threshold for at least 4 years.
OBJECTIVE: Vaccination serves as the most efficacious intervention to prevent influenza-related illness. The aim of this study was to compare the lifetime cost-effectiveness of a fully-funded trivalent inactivated influe...OBJECTIVE: Vaccination serves as the most efficacious intervention to prevent influenza-related illness. The aim of this study was to compare the lifetime cost-effectiveness of a fully-funded trivalent inactivated influenza vaccine (TIV) strategy for people aged 60 years and over. METHODS: A static decision-tree Markov model was employed to conduct a lifetime economic evaluation from a societal perspective. Model parameters such as probabilities, costs and utility values, were derived from regional health information platform, published literature, and investigation. The number of cases and deaths averted, quality-adjusted life years (QALYs) gained, and the incremental cost-effectiveness ratio (ICER) were predicted. Sensitivity analyses were performed to evaluate the uncertainty of results. RESULTS: Compared with self-paid vaccination, the implementation of the free influenza vaccination program is projected to cumulatively reduce 261,374 non-medically attended influenza cases,370,155 outpatient influenza cases, 13,678 hospitalized influenza cases, and 1987 influenza-associated deaths. It is estimated that this programme will generate cumulative cost savings of $2,184,312 and an additional 14,324 QALYs, rendering it a dominant strategy. At a willingness-to-pay (WTP) threshold of one times of the per capita gross domestic product (GDP) of Ningbo, the probability of the programme being cost-effective is 99.88%. The threshold analysis revealed that the threshold price of TIV is $11.18 under the most conservative WTP threshold. CONCLUSIONS: It has been demonstrated that the free influenza vaccination policy are cost-effective for the elderly individuals. The government and health authorities are supposed to implement and promote a universal free influenza vaccination programme for the elderly, with particular emphasis on the oldest age groups.