: Seasonal influenza vaccines must be reformulated annually due to the high genetic variability and antigenic drift of circulating influenza viruses. The annual update, guided by World Health Organization (WHO) recommendations, results in significant challenges, including compressed production time periods, elevated manufacturing costs, and global distribution pressures. Moreover, mismatches between vaccine strains and circulating viruses can severely reduce protective efficacy, underscoring the urgent need for broadly protective and long-lasting influenza vaccines. : In this study, we developed an adjuvanted trivalent recombinant influenza virus-like particle vaccine (a-RIV) using the baculovirus-insect cell expression system and formulated it with an AS01-like adjuvant. The vaccine comprises full-length hemagglutinin (HA) proteins from WHO-recommended seasonal influenza strains: A/H1N1 (AH1), A/H3N2 (AH3), and B/Victoria (B/vic) lineages. The purified HA proteins were subsequently formulated with a liposomal adjuvant to enhance the immunogenicity. : In mouse immunization studies, the a-RIV vaccine elicited significantly stronger humoral and cellular immune responses than the licensed recombinant vaccine Flublok and the conventional inactivated influenza vaccine (IIV). High levels of functional anti-HA antibodies and antigen-specific T cell responses persisted for at least six months post-vaccination. Moreover, a-RIV induced broadly reactive antibodies capable of cross-binding to heterologous AH1 and AH3 influenza strains. : Our data demonstrate that the a-RIV elicits enhanced, durable, and broadly cross-reactive immune responses against multiple influenza subtypes. These findings support the potential of adjuvanted recombinant HA-based vaccine as a promising candidate for the development of next-generation influenza vaccine.

The development of an effective HIV-1 vaccine remains a major challenge due to HIV-1's extraordinary diversity, high mutation rate, and the rarity of broadly neutralizing antibody (bnAb) precursors. To address these challenges, we have previously immunized rabbits with mRNA-LNPs encoding for HIV-1 envelope glycoproteins (Envs), together with mRNA-LNPs encoding for HIV-1 Gag, which likely mediated the generation of virus-like particles presenting HIV-1 Envs to the immune system in vivo.

Influenza viruses remain a major global public health concern, causing significant morbidity and mortality annually despite widespread vaccination efforts. The limitations of current seasonal vaccines, including strain-specific efficacy and manufacturing delays, have accelerated the development of next-generation candidates aiming for universal protection. This review comprehensively summarizes the recent progress in universal influenza vaccine research. We first outline the key conserved antigenic targets, such as the hemagglutinin (HA) stem, neuraminidase (NA), and matrix proteins (M2e, NP, and M1), which are crucial for eliciting broad cross-reactive immunity. We then delve into advanced antigen design strategies, including immunofocusing, multi-antigen combinations, computationally optimized broadly reactive antigens (COBRA), and nanoparticle-based platforms. Furthermore, we evaluate evolving vaccine delivery systems, from traditional inactivated and live-attenuated vaccines to modern mRNA and viral vector platforms, alongside the critical role of novel adjuvants in enhancing immune responses. The convergence of these disciplines-structural biology, computational design, and nanotechnology-is driving the field toward a transformative goal. We conclude that the successful development of a universal influenza vaccine will likely depend on the strategic integration of these innovative approaches to overcome existing immunological and logistical challenges, ultimately providing durable and broad-spectrum protection against diverse influenza virus strains.

Following the global spread of SARS-CoV-2, there was an urgent need for vaccine development to support immune protection. This study aimed to evaluate the impact of active and hybrid immunity on the durability of immunoglobulin G (IgG), neutralizing antibodies, and cellular immune responses over a two-year period.

The 20-valent pneumococcal conjugate vaccine (PCV20) was approved for use in children and infants on the basis of studies comparing its safety and immunogenicity with those of the 13-valent vaccine (PCV13). PCV20 offers expanded coverage of seven additional serotypes. This meta-analysis aimed to summarize the available evidence on the comparative immunogenicity between PCV20 and PCV13.

Viral hepatitis constitutes a substantial global public health challenge. The etiological agents, referred to as hepatitis viruses, are primarily categorized into five types: hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV). Among the various preventive strategies, vaccination is widely acknowledged as the most cost-effective and efficient method for controlling viral hepatitis and its related hepatic complications. To date, numerous countries have initiated extensive vaccination programs targeting hepatitis A and hepatitis B. Advances in biotechnology have facilitated substantial progress in vaccine formulation design, the development of innovative adjuvants, and the utilization of novel vectors. However, significant challenges persist, including inadequate vaccination coverage, inconsistent immune responses among vulnerable populations, and concerns regarding vaccine safety. This article presents a systematic review of recent advancements, the current status of vaccination efforts, and ongoing challenges associated with hepatitis vaccines, with the objective of providing critical insights to support the World Health Organization's goal of eliminating viral hepatitis as a public health threat by 2030.

Seasonal human coronaviruses (HCoVs), including HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1, circulate globally in an epidemic pattern and account for a substantial proportion of common cold cases, particularly in infants, the elderly, and immunocompromised individuals. Although clinical manifestations are typically mild, these HCoVs exhibit ongoing antigenic drift and have demonstrated the potential to cause severe diseases in certain populations, underscoring the importance of developing targeted and broad-spectrum vaccines. This review systematically examines the pathogenesis, epidemiology, genomic architecture, and major antigenic determinants of seasonal HCoVs, highlighting key differences in receptor usage and the roles of structural proteins in modulating viral tropism and host immunity. We summarize recent advances across various vaccine platforms, including inactivated, DNA, mRNA, subunit, viral-vectored, and virus-like particle (VLP) approaches, in the development of seasonal HCoV vaccines. We specifically summarize preclinical and clinical findings demonstrating variable cross-reactivity between SARS-CoV-2 and seasonal HCoV vaccines. Evidence indicates that cross-reactive humoral and cellular immune responses following SARS-CoV-2 infection or vaccination predominantly target conserved epitopes of structural proteins, supporting strategies that incorporate conserved regions to achieve broad-spectrum protection. Finally, we discuss current challenges in pathogenesis research and vaccine development for seasonal HCoVs. We propose future directions for the development of innovative pan-coronavirus vaccines that integrate both humoral and cellular antigens, aiming to protect vulnerable populations and mitigate future zoonotic spillover threats.

: Influenza is a major health threat to the elderly in China. Despite this, influenza vaccination rates still remain low and vary across regions that have different funding policies. In this study, we compare the vaccination status and influencing factors among older adults under the free, partial reimbursement, and self-paid vaccination strategies. : Three cities with free, partial reimbursement, and self-paid influenza vaccination policies were selected. A cross-sectional, anonymous survey was then conducted. A total of 2265 elderly individuals aged 60 years and above were recruited using probability proportionate to size sampling. A standardized questionnaire was used during face-to-face interviews to collect data regarding the influenza vaccination status and influencing factors. The statistical analyses included chi-square tests, a multivariate logistic regression, and random forest models. : Among the 2265 participants (free policy region: = 426; partial reimbursement region: = 633; self-paid region: = 1206), vaccination rates during the 2023-2024 season were significantly higher in the free policy region (53.29%) than in the partial reimbursement (20.85%) and self-paid (13.60%) regions ( < 0.001). The intention to vaccinate for the 2024-2025 season was also highest in the free policy region (68.78%), followed by partial reimbursement (47.71%) and self-paid (37.15%) regions ( < 0.001). This result demonstrated the same trend as the vaccination behavior. Cues to action (e.g., healthcare worker or family member recommendations) positively influenced vaccinations across all of the regions. In the self-paid region, perceived barriers, such as vaccine cost and side effect concerns, significantly reduced both behaviors and the next-season intention to vaccinate. Healthcare worker recommendations were key positive factors, while misconceptions and costs were major barriers to vaccination. : Vaccination rates varied significantly across regions with different influenza vaccine subsidy policies. The free policy region demonstrated the highest coverage rate, while the self-paid region exhibited the lowest, suggesting that financial policies are a key determinant of vaccination uptake. Furthermore, free vaccination policies were associated with improved influenza vaccine knowledge among the elderly. Analysis of other influencing factors revealed that healthcare workers' recommendations played a crucial role across all policy regions, though their impact on current-season vaccination behavior and next-season vaccination intention differed by subsidy context. Further studies are needed to explore the best approaches for optimizing region-specific subsidy strategies for promoting influenza vaccination among the elderly in China.

Respiratory syncytial virus (RSV) causes severe infection in neonates and infants. However, a suitable RSV vaccine for children is yet to be approved. The development of KD-409 is focused on creating an effective and safe RSV vaccine for newborns and children. The safety and efficacy of the RSV FG chimeric protein KD-409 were evaluated in several rodent models.

Japan is a rabies-free country; therefore, pre-exposure prophylaxis (PrEP) is primarily recommended for travelers to rabies-endemic regions. However, no prior studies in Japan have assessed long-term immunogenicity after PrEP vaccination.

Influenza vaccination reduces morbidity and mortality in older adults. This study identifies characteristics and reasons for vaccination uptake among the elderly to inform strategies to improve coverage. We conducted a cross-sectional survey in December 2024 among community-dwelling adults aged ≥ 60 years across six Chinese cities. Data collected included socio-demographic and health characteristics, influenza vaccine awareness and uptake, reasons for vaccination or non-vaccination, and intentions for future vaccination. Univariate and multivariable logistic regression were used to identify factors associated with vaccination. To explore motivation patterns, co-occurrence networks of vaccination reasons were constructed, and k-medoids clustering was applied. : Among 13,363 adults aged ≥ 60 years, influenza vaccination coverage was 34.0%. Higher education and income, being married, having health insurance, poor self-care ability, and chronic obstructive pulmonary disease were independently associated with vaccination. Vaccinated individuals reported more positive attitudes and were mainly motivated by family and doctor recommendations as well as perceived vaccine effectiveness, with four motivation profiles discovered: social recommendation, comprehensive confidence, clinician-guided, and self-reliant confidence. Among unvaccinated participants, the main reasons for non-vaccination were mild influenza symptoms and the influence of family and friends, forming four motivation profiles: safety concern, low-perceived risk, social influence, and perceived ineffectiveness. : Influenza vaccination among older Chinese adults remains suboptimal. Tailored interventions leveraging healthcare provider endorsement, family and social support, and policy-driven strategies such as free or subsidized vaccination are needed, particularly for high-risk populations.

: The minimized pan-coronavirus (CoV) vaccine-1 developed by our laboratory contained pDNA sequences of feline coronavirus serotype-1 (FCoV1) and SARS-CoV2 (SCoV2) spike B-cell epitopes plus FCoV/SCoV2-conserved, CoV-specific polymerase cytotoxic T-lymphocyte (CTL) epitopes formulated in lipid nanoparticle (LNP). Only FCoV2 infects feline cell lines needed for developing native challenge inoculum that causes feline infectious peritonitis (FIP). Hence, Pilot Study 1 evaluated the therapeutic efficacy and safety of the pan-CoV vaccine-1 in feline immunodeficiency virus (FIV)-infected cats, with or without FCoV1 coinfection. Pilot Study 2 evaluated the cross-protective effect of pan-CoV vaccines in specific-pathogen-free (SPF) cats against intranasal challenge with FIP virus serotype 2 (FIPV2). : In Study 1, we vaccinated two FIV-infected cats (one negative and another positive for FCoV1 coinfection) intramuscularly twice with CTL epitopes-LNP vaccine and later twice with pan-CoV vaccine-1. Controls included two unvaccinated FIV-infected cats with or without FCoV1 coinfection. Study 2 assessed the sequential vaccinations of three pan-CoV vaccines in four SPF cats. The first two vaccinations were with pan-CoV vaccine-2, followed by pan-CoV vaccine-3 (twice), and lastly with pan-CoV vaccine-1 (once). Three SPF controls included two cats immunized with LNP and one lacking any immunization. Pan-CoV vaccine-2 contained pDNAs with modified FCoV1/SCoV2 B-cell epitopes plus CTL epitopes in LNP. Pan-CoV vaccine-3 contained only pDNAs with FCoV1 B-cell epitopes plus CTL epitopes in LNP. : Study 1 demonstrated no adverse effect with 25 μg and 50 μg CTL epitopes-LNP vaccine and 50 μg pan-CoV vaccine-1. However, 100 μg pan-CoV vaccine-1 caused fever 24 h later, which was resolved by a single Meloxicam treatment. Both vaccinees developed cross-FCoV2 neutralizing antibodies (XNAbs), immunoblot binding antibodies (bAbs) to FCoV1 receptor-binding domain (RBD), and T-cell responses to FCoV1 RBD, whereas one vaccinee also developed bAbs to SCoV2 RBD. Study 2 demonstrated no adverse effects after each vaccination. Three vaccinees developed low-titer XNAbs and bAbs to FCoV2 spike-2 by the fourth vaccination. Upon challenge, all cats developed FCoV2 NAbs and bAbs to FCoV2 nucleocapsid and RBD. High vaccine-induced T-cell responses to FCoV1 RBD and T-cell mitogen responses declined with an increase in responses to FCoV2 RBD at three weeks post-challenge. Two of the three controls died from FIP, whereas one vaccinee, with the lowest vaccine-induced immunity, died from skin vasculitis lesions and detection of FIPV2 infection by semi-nested RT-snPCR in feces. : In Pilot Study 1, the pan-CoV vaccine-LNP dose of 50 μg had no adverse effects, but adverse effects were observed at 100 μg dose. In Pilot Study 2, the FCoV1-based B-cell vaccine(s) induced low levels of XNAbs against FIPV2 and delayed challenge infection against high-dose FIPV2. The high-dose FIPV2 infections in the vaccinated and control cats started to clear, by single housing at 23-26 weeks post-challenge, whereas two cats in Pilot Study 1 cleared natural FCoV1 transmission by 26 weeks post-infection.

: Cervical cancer (CC) continues to be an important public health concern in Latin America, where it is the second cause of cancer-related deaths among women. With its strong culture of vaccination, Panama was the first country to implement the HPV vaccine as part of its Essential Program on Immunization (EPI). Recently, the government implemented the 90:70:90 PAHO/WHO strategy to reach milestones toward CC elimination. : This analysis triangulates and assesses national data on HPV vaccination coverage, screening practices, and cervical cancer incidence and mortality in Panama, to understand historical tendencies to date and establish a comprehensive foundation for future impact evaluations and research studies. The analysis aims to identify trends and gaps in prevention efforts and to serve as a reference point for future research on HPV-associated cancers. : Population-based, descriptive, observational, ecological study where four, aggregate, de-identified data sources by various curators in Panama were match-merged by year, sex, and administrative division. Reported outcomes include HPV vaccine coverage, CC incidence and mortality rates, screening Pap tests, and CC behavior at diagnosis (in situ vs. invasive). : Panama has high HPV vaccine uptake (≥85% most years) in spite of low Pap test coverage (~10%). A decreasing trend in CC incidence has been observed continuously since the 1990s, counterintuitively to significantly increasing CC mortality rates, with most cases diagnosed as invasive and among younger women (30-69 years old). : This report provides a comprehensive foundation for understanding trends in HPV vaccination coverage, cervical cancer incidence and mortality, and screening practices in Panama. While high vaccine uptake and declining incidence trends are encouraging, persistent low screening rates and elevated mortality-particularly at invasive stages among younger women-highlight critical gaps in prevention efforts. The need for integrated strategies that strengthen data systems, improve early detection, and address structural and sociocultural barriers are discussed, framed within Panama's progress toward achieving the 90:70:90 targets. Future studies should focus on understanding non-medical influences on health and further vaccine impact with patient-level data, and other forms of HPV-related cancers in immunosuppressed populations. Public strategies would benefit from the implementation of real-life data and efficient data management, consolidation systems, systematic health promotion interventions, and an increase in resource allocation for women at the highest risk.

Local production is a global priority for increasing access to routine, outbreak, and pandemic vaccines and leads to a variety of direct and indirect benefits for countries. This study aimed to characterize the enabling environment for the sustainable production of influenza vaccines, including for epidemic and pandemic preparedness. National/local vaccine manufacturers were surveyed to capture data on influenza vaccine market contributions, government support for local production, and involvement in national pandemic preparedness activities. Using a conceptual framework for sustainable local production of influenza vaccines for epidemic and pandemic preparedness, manufacturers described 41 global/regional, national, and institutional sustainability factors across policy, health system, research and development (R&D), and regulatory thematic domains. In addition to the survey, key findings from country-level sustainability assessments of vaccine production in Bangladesh, Brazil, Indonesia, Serbia, and Viet Nam were analyzed to complement survey results. This study included 12 participants representing 11 manufacturers from 10 countries. Of the 11 manufacturers, six reported that their countries have policies that support local production, but most manufacturers reported benefiting from some level of direct or indirect support by the government. Manufacturers considered 40/41 factors as important for sustainable production of influenza vaccines, and among the four domains, influenza prevention and control policies, influenza burden data, quality management, and regulatory filing capacity ranked highly. Additionally, manufacturers ranked factors related to cohesive policies for local production promotion and business/strategic planning at the manufacturer level as the top sustainability factors. Manufacturers broadly agreed on the importance of cohesive policies, evidence-based public health priorities, robust R&D and manufacturing investments, and regulatory readiness, though perceptions varied across contexts and company characteristics. Sustainable local production of influenza vaccines should be driven by the alignment of policies, investments, and demand.

The emergence of SARS-CoV-2 variants with enhanced immune evasion capabilities poses ongoing challenges for maintaining population-level immunity. This study aim to evaluate neutralizing antibody responses to the wild-type (WT) strain and the Omicron sublineage XBB.1.9 in the Israeli population using serum samples collected between August 2022 and January 2023, prior to widespread circulation of XBB.1.9.

The immunogenicity of polysaccharide conjugate vaccines is critically influenced by the choice of carrier protein, which promotes a T-cell-dependent immune response mechanism leading to strong antibody production. In this study, the cholera toxin B subunit (CTB), a non-toxic pentameric protein, was evaluated as a novel carrier protein for pneumococcal polysaccharide antigens. : Recombinant CTB was produced in and purified using scalable chromatographic methods. Pneumococcal polysaccharides from serotypes 7F, 22F, and 33F were chemically activated with CDAP and conjugated to CTB. The resulting glycoconjugates were characterized by SEC-MALS, confirming successful conjugation, high molecular weights, consistent polysaccharide-to-protein ratios, and acceptable endotoxin levels. Immunogenicity was assessed in rabbits following immunization with alum-adjuvanted formulations. : Robust IgG responses were elicited by all CTB-based conjugates, with antibody levels found to be comparable to those induced by CRM197 conjugates, demonstrating the potential of CTB as a promising alternative for the next generation of conjugate vaccines.

Varicella zoster virus (VZV) remains a significant cause of pediatric morbidity in populations in Lebanon, yet comprehensive data on population immunity and vaccination uptake are limited. This study aimed to estimate VZV seroprevalence and identify factors associated with immunity and vaccine uptake among children and adolescents in Northern Lebanon.

Rotavirus (RV) continues to be the leading cause of acute gastroenteritis (AGE) globally among children under five. National RV vaccination efforts have lowered morbidity and mortality. Vaccination is a key public health tool to alleviate this substantial burden of RV in middle- and low-income countries. In Syria, RV morbidity accounts for 27% of severe GE. We conducted a cost-effectiveness analysis of introducing rotavirus vaccinations (RVV) into Syria's National Immunization Program. A decision tree model was developed to assess the cost-saving of two-dose rotavirus vaccinations (Rotarix) compared to no vaccination. A birth cohort of 573,944 newborns was simulated throughout a 5-year time frame to capture the near-term health and economic effects. The analysis adopted an incremental cost-saving approach, evaluating a hypothetical 2023 birth cohort from the government's perspective. Outcomes included the cost per disability-adjusted life year (DALY) prevented and the cost per death averted. Model inputs were derived from local data, specifically including healthcare and vaccination costs and deaths attributable to RVGE, the scientific literature, and national/international databases. The incremental cost-effectiveness ratio (ICER) measures the cost of avoiding one disability-adjusted life year (DALY) adopted. Over five years, the two-dose RV strategy would avert 77,500 RVGE cases, reduce outpatient visits by 59%, and reduce severe RV hospitalizations by 41%. The vaccination program would cost $21,817,918 USD and avert $3,239,907 USD in healthcare costs, resulting in a net cost of $18,578,011 USD. The incremental cost-effectiveness ratio (ICER) was $2098 USD per DALY averted, which is below three times Syria's GDP per capita ($753.6 USD), indicating high cost-effectiveness according to WHO benchmarks. Introducing rotavirus vaccination is highly cost-saving and will result in a substantial reduction in healthcare burdens and lives lost. Policy planners must ensure its inclusion in the National Immunization Programs, ensuring sustainable financing and equitable access.

: Following the COVID-19 pandemic, the influenza season returned to its typical pre-pandemic circulation patterns. The category of people most vulnerable to severe influenza was older adults, and frail individuals, confirming their central role as a priority group for vaccination. The objective of this study was to evaluate the impact of an active influenza vaccination program in an area with low influenza vaccination rates and propensity to vaccine co-administration. : People recruited were hospitalized frail individuals, patients over the age of 60, and those with chronic illnesses or comorbidities. It was administered a questionnaire to investigate adherence to influenza vaccination and the Health Action Process Approach was used to evaluate the propensity to co-administration. : A total of 418 hospitalized patients were enrolled in the study, of whom 58.4% (n = 244) received the influenza vaccine and 17.9% (n = 75) had a higher propensity to have co-administration of influenza and other recommended vaccines. The factors associated with influenza vaccination acceptance were received advice from hospital healthcare workers (aOR = 10.6 < 0.001) and previous influenza vaccination (aOR = 18.1; < 0.001). Propensity to vaccine co-administration was associated with a higher educational level (aOR = 4.21; = 0.002), receiving vaccination advice from hospital healthcare workers (aOR = 2.80; = 0.03), perceived positive outcome (aOR = 1.29; = 0.02) and perceived self-efficacy (aOR = 1.48; < 0.001). Conslusions: This study explored the impact on influenza vaccination coverage in implementing in hospital vaccination offer. The reliability of this strategy, together with the standard vaccination offer, could allow reaching the recommended vaccination coverage, particularly among at-risk people.

Bovine coronaviruses (BCoV) are endemic worldwide, causing diarrhea, winter dysentery, and bovine respiratory disease in newborn calves. These lead to higher calf mortality, reduced growth of fattening cows, and lower milk production in adult cows, resulting in significant losses to the cattle industry. Since commercial preventive drugs are not available in China, and existing treatments can only reduce the mortality of sick calves without fundamental control, the development of safe and effective vaccines is crucial.

: HPV vaccination uptake among adolescents and young adults in the US remains low, and coverage in the Midwest falls short of the Healthy People 2030 goal of 80%. : A cross-sectional survey of adolescents and young adults was conducted to identify facilitators and barriers to HPV vaccination uptake among adolescents and young adults in the Midwest. : Out of 1306 individuals aged 13-26 years, 397 (30.4%) were fully vaccinated (2-3 doses), 124 (9.5%) had received one dose, 324 (24.8%) were unvaccinated, and 461 (35.3%) were unsure of their vaccination status. Awareness of HPV vaccines (OR: 2.4, 95% CI: 1.6, 3.6), beliefs about vaccine effectiveness (OR: 1.8, 95% CI: 1.1, 2.9), family support (OR: 2.3 95% CI: 1.4, 3.8) and knowing someone with cervical cancer (OR: 1.8, 95% CI: 1.2, 2.7) were associated with increased odds of full vaccination. Beliefs in vaccine safety (OR: 2.0, 95%CI: 1.0, 3.9) and having health insurance coverage (OR: 1.9, 95% CI: 1.0, 3.5) were associated with increased odds of initiated vaccination (i.e., receiving at least one dose). Concerns about vaccine side effects (OR: 0.5, 95% CI: 0.3, 0.8) and not receiving recommendations from doctors were significantly associated with decreased odds of full vaccination (OR: 0.5, 95% CI: 0.3, 0.8) or initiated vaccination (OR: 0.5% CI: 0.2, 0.9). Clinician recommendations and awareness also reduced the likelihood of unknown vaccination status. Race-stratified analyses suggested heterogeneity in predictors across racial/ethnic groups. : Our findings support the need for multi-level interventions aimed at increasing HPV vaccination initiation and completion in the Midwest.