Vaccines最新文献

Background/objectives: African swine fever virus (ASFV), the causative agent of African swine fever (ASF), is a highly contagious virus affecting both domestic and feral pig populations with mortality rates approaching 100% within one week of infection. Currently, there are limited treatments or vaccines available to control the disease. Although ASF is endemic in sub-Saharan Africa, the virus has also spread widely, reaching regions of the European Union, Russia, China, Southeast Asia, and, more recently, to the Dominican Republic and Haiti, bringing the threat closer to the United States (U.S.). ASF introduction to the U.S. would have severe consequences for swine producers and the national pork industry. Consequently, there is an urgent need to develop effective vaccine strategies to manage ongoing outbreaks abroad and mitigate the risk of future ASF incursions. Recent efforts have identified several ASFV epitopes and evaluated them in experimental vaccine trials. However, these vaccine candidates have elicited limited protective immune responses and have not demonstrated full protective efficacy.

Methods: In this study, we employed in silico modeling and epitope prediction tools to design a synthetic multiepitope ASF protein incorporating key immunogenic regions of ASFV. The goal was to generate a single-antigen construct capable of inducing broad and robust immune responses when formulated with an established nanoparticle-based vaccine platform. The multiepitope ASF protein was subsequently expressed and entrapped into mannose-conjugated chitosan (M-CS) nanoparticles for vaccine formulation. The candidate vaccine, formulated with M-CS nanoparticle-entrapped adjuvant (ADU S100), was administered intramuscularly to pigs, and both T- and B-cell responses were assessed following the primary (DPV 22) and booster (DPV 42) doses.

Results: Our M-CS ASF protein vaccine elicited antigen-specific T- and B-cell responses, both of which are recognized as central correlates of protection against ASFV.

Conclusions: These promising preliminary immunological findings suggest that this nanoparticle vaccine has the potential to confer protection against ASFV challenge, a hypothesis that will be examined in future studies.

Background: Respiratory syncytial virus (RSV) remains a major etiologic agent of acute lower respiratory tract infection (ALRTI). Currently licensed RSV vaccines are administered by intramuscular injection and induce limited immunity at the respiratory mucosal interface, underscoring the need for effective mucosal vaccination strategies.

Methods: To enhance mucosal immune responses, we used prefusion F protein (Pre-F) as the antigen and performed intranasal immunization in BALB/c mice. Four mucosal adjuvants (CpG-ODN, CTA1-DD, IFN-α, and PEI) were systematically compared across different dose levels to evaluate their immunological and protective efficacy.

Results: Both adjuvant type and dose helped shape the magnitude and quality of the immune response and the level of protection. CpG-ODN showed a dose-restricted immunopotentiating effect: an intermediate dose (10 µg) significantly increased neutralizing antibody titers and nasal mucosal IgA responses, improved post-challenge body weight recovery, and reduced lung viral load, whereas higher doses provided no additional benefit and were associated with aggravated lung pathology. PEI and IFN-α exhibited dose-dependency within a certain range, but increasing doses did not result in further improvements in immune responses or protection; an intermediate dose (10 µg) was sufficient to elicit robust systemic and mucosal immunity. CTA1-DD improved selected immune parameters at appropriate doses, yet its overall immunopotentiating effects remained modest. Direct comparative analysis using the representative doses selected from the three dose levels for each adjuvant indicated that 10 µg CpG-ODN or PEI provided superior immunogenicity and protection, whereas PEI induced a Th2-biased immune profile at both humoral and cellular levels.

Conclusions: These findings highlight that favorable immunogenicity and protection are achieved within defined dose windows rather than at maximal doses. Among the adjuvants studied, low-to-intermediate doses of CpG-ODN, particularly 10 µg, show strong potential for intranasal mucosal immunization with recombinant RSV Pre-F protein. By systematically comparing dose-effect profiles across multiple mucosal adjuvants, this study offers comparative insights into adjuvant selection and dose selection for intranasal RSV vaccine development.

Background: Follicle-stimulating hormone (FSH)-based vaccines show the potential to disrupt spermatogenesis without disturbing sexual function and libido in males. Herein, we developed a novel FSH vaccine based on the tandem of a conserved 13-amino acid receptor-binding epitope of FSHβ (FSHβ13AA-T) and tested its effect on reproductive physiology and function using the male mouse as a model.

Methods: Serum reproductive hormone levels, testicular histology, daily sperm production, sperm motility, libido and fertility of male mice following FSH vaccination were determined.

Results: Compared to placebo-immunized controls, FSH vaccination triggered (p < 0.05) marked antibody generation, inhibited spermatogenesis and reduced sperm motility (p < 0.05), without adverse effects on serum LH and testosterone levels as well as the libido of male mice. Mechanistically, FSH vaccination suppressed (p < 0.05) testicular local estrogen production by downregulated aromatase encoding gene Cyp19a1 expression and also downregulated (p < 0.05) expression of key spermatogenic genes in testes, including Creb, INHα, Wnt2, Aqp8, Cmtm2a and Spata19, thus disrupting and impairing spermatogenesis and sperm motility.

Conclusions: These results demonstrate that immunization of male mice against FSHβ13AA could substantially inhibit spermatogenesis and reduce sperm motility. Thus, FSHβ13AA-based vaccines hold potential for development as male contraceptives that do not compromise libido in species including men in which FSH is essential for spermatogenesis.

Population aging is the most significant demographic transformation of the 21st century, reshaping health systems, economies, and societies. The biological processes of immunosenescence and inflammaging weaken host defenses, reduce vaccine effectiveness, and increase vulnerability to infectious and chronic diseases. These changes underscore the urgent need for preventive strategies that extend beyond childhood immunization. Vaccination is a cornerstone of healthy aging, capable of preventing infections and has been associated with reductions in systemic inflammation, frailty, and loss of functional independence in later life. Furthermore, new insights into vaccine-mediated immunomodulation, including trained immunity, adjuvanted formulations, and epigenetic reprogramming, highlight the evolving role of vaccines as modulators of immune fitness across the lifespan. This first part of our review examines the intersection of aging and immunity, as well as the potential of vaccines to address these challenges. Part 2 will expand on specific vaccines, proposed vaccination schedules, and global perspectives for lifelong immunization.

Background/objectives: Human papillomavirus (HPV) is the most common sexually transmitted virus worldwide and is frequently detected in women of reproductive age. In this population, HPV-related diseases and their management may affect reproductive health and pregnancy outcomes. This narrative review summarizes the current evidence on HPV infection and HPV-related diseases in relation to fertility, pregnancy, and neonatal outcomes, and discusses preventive strategies, with a particular focus on HPV vaccination.

Methods: An international, multidisciplinary team of clinicians from the European Society of Gynaecological Oncology (ESGO) Prevention Committee reviewed the literature on HPV, HPV-related diseases, HPV vaccination, and reproductive outcomes, without time restrictions, prioritizing studies judged to meaningfully reflect the available evidence.

Results: The most consistent evidence linking HPV-related conditions to adverse pregnancy outcomes relates to the treatment of cervical precancer, particularly excisional procedures, which are associated with an increased risk of preterm birth and mid-trimester pregnancy loss. In contrast, evidence that maternal HPV detection alone causes adverse pregnancy or neonatal outcomes remains limited and inconsistent. Data on HPV infection and subfertility are scarce and heterogeneous. Management of HPV-related lesions during pregnancy remains challenging and requires careful balancing of maternal safety with avoidance of unnecessary interventions. HPV DNA has been detected in neonatal samples, but convincing evidence for clinically relevant vertical transmission is lacking. Available data indicate that inadvertent HPV vaccination shortly before or during pregnancy is not associated with adverse pregnancy outcomes.

Conclusions: Current evidence suggests that reproductive risks are more strongly associated with the treatment of HPV-related diseases than with HPV infection itself. Preventive strategies-especially HPV vaccination-remain central to reducing HPV-related disease burden. Although HPV vaccines are not routinely recommended during pregnancy, evidence supports the safety of inadvertent exposure around conception or during gestation, while potential long-term benefits of vaccination regarding reproductive health require further study.

Background: SARS-CoV-2 infection has raised concerns about altered immune responses, creating a need to evaluate influenza vaccine performance in the post-COVID period. This study aimed to compare the immunogenicity and safety of a quadrivalent inactivated subunit adjuvanted influenza vaccine in adults aged 18-85 years during the 2022-2023 season. Methods: A total of 144 adults were enrolled: group 1, aged 18-59 years (n = 124), and group 2, aged 60-85 years (n = 20). All received a quadrivalent inactivated subunit adjuvanted vaccine containing 5 μg of each influenza antigen and 500 μg of Azoximer bromide. IgG antibodies to vaccine strains were measured at baseline and days 30-32 using the hemagglutination inhibition assay. Participants were actively monitored for adverse events by telephone. Results: The Geometric Mean Fold Increase (GMFI) met the efficacy criteria in both age groups (≥2.5 for 18-59 years and ≥2.0 for 60-85 years), with no significant differences. The seroprotection rate reached accepted thresholds for most strains but was below criteria for B/Victoria in the 18-59 group (48%) and for B/Phuket in the 60-85 group (35%). Significant between-group differences were observed for B/Victoria (p = 0.01) and B/Phuket (p = 0.007). Seroconversion met criteria for all strains in younger adults, but for older adults, it was insufficient for B/Phuket (20%, below the ≥30% threshold; p = 0.05 vs. 18-59 years). Local reactions occurred in 24.2% and systemic in 11.3% of younger adults; in older adults, in 20% and 15%, respectively. All resolved spontaneously within 1-3 days. Conclusions: The quadrivalent adjuvanted influenza vaccine demonstrated acceptable immunogenicity and safety in adults aged 18-85 years despite potential post-COVID immune alterations.

Persistent infection with hepatitis D virus (HDV), also known as hepatitis delta, is considered the most severe form of chronic viral hepatitis. HDV is a defective RNA virus that depends on hepatitis B virus (HBV) for propagation. Despite its global distribution, HDV stays a neglected part of the viral hepatitis agenda, often overlooked in surveillance systems and public health policy. This oversight is particularly concerning given HDV's aggressive clinical course, characterized by more rapid progression to cirrhosis, liver failure, and hepatocellular carcinoma (HCC) compared to HBV mono-infection. Mongolia has the highest incidence and mortality rates of HCC worldwide, with approximately 47% of cases estimated to be attributable to chronic HDV infection. Globally, an estimated 12-25 million people are co-infected with HBV and HDV, although the true prevalence is higher due to insufficient screening and incomplete data collection. Because HDV infection is entirely dependent on HBV, prevention of HBV infection through effective vaccination stands for an indirect yet highly effective strategy to curb HDV transmission. The World Health Organization (WHO), together with the global health community, has established ambitious targets to eliminate viral hepatitis as a public health threat by 2030. However, achieving HDV elimination remains particularly challenging due to limited diagnostic capacity, low awareness, and minimal inclusion of HDV in national hepatitis programs. This review explores the intersection of HDV and HBV, focusing on how expanded and optimized HBV vaccination coverage can serve as a cornerstone of global HDV prevention efforts. We examine epidemiological evidence, scientific rationale, policy developments, and key implementation challenges, with particular attention to high-burden settings such as Mongolia. Finally, we propose strategic recommendations to bridge policy and practice gaps in HDV elimination.

Background: Respiratory syncytial virus (RSV) is a leading cause of hospitalization in early infancy, with the greatest burden occurring in the first months of life. Following the COVID-19 pandemic, many countries experienced intensified RSV circulation. Nirsevimab, a long-acting monoclonal antibody providing season-long protection after a single dose, was introduced in Italy for the 2024-2025 RSV season and recommended for infants born during the period of RSV circulation. We evaluated the population-level impact of this seasonal nirsevimab strategy on RSV-related hospitalizations among young infants.

Methods: We conducted a population-based observational study using regional hospital discharge records from Emilia-Romagna, Northern Italy, spanning January 2017 to April 2025. Analyses were restricted to RSV seasons (October-March) and infants aged ≤180 days. RSV-related hospitalizations were identified using ICD-9-CM codes. Hospitalization rates were calculated per 100,000 person-days. Incidence rate ratios (IRRs) were estimated using negative binomial regression models adjusted for season, age group, and sex, with clustering at the hospital level. The post-nirsevimab season (2024-2025) was compared with the immediate pre-nirsevimab season (2023-2024) and a pre-COVID reference season (2018-2019).

Results: A total of 551 RSV hospitalizations occurred in the pre-COVID season, 753 in the pre-nirsevimab season, and 252 in the post-nirsevimab season. The post-nirsevimab season was associated with a substantial reduction in RSV-related hospitalization rates compared with both the pre-COVID season (IRR 0.52; 95% CI 0.41-0.66) and the pre-nirsevimab season (IRR 0.36; 95% CI 0.29-0.44). Reductions were observed consistently across epidemic months and were most pronounced during the first three to four months of life.

Conclusions: Seasonal administration of nirsevimab to infants born during the RSV circulation period was associated with a marked and sustained reduction in RSV-related hospitalizations in early infancy. These findings support the effectiveness of targeted, seasonally timed infant immunoprophylaxis as a population-level RSV prevention strategy.

This study aimed to explore the cognitive levels and influencing factors of Shanghai residents regarding non-immunization program vaccines. A population-based study was conducted in Shanghai in 2024. Objective: To examine awareness levels and factors influencing perceptions of non-National Immunization Program (non-NIP) vaccines among residents of Shanghai. Methods: A population cross-sectional survey was conducted in Shanghai from 20 October to 31 December 2024, using stratified random sampling. Five districts were selected, four communities per district were randomly chosen, and 35-40 residents per community were invited to complete a questionnaire. Data collected included sociodemographic characteristics, awareness of non-NIP vaccines, and potential influencing factors. Awareness and acceptance of non-NIP vaccines were measured using five-point Likert scales. On a 0-4 scale, where 0 = completely unaware/unsupportive and 4 = very aware/strongly supportive, respondents rated their level of understanding and endorsement of non-NIP vaccines. Descriptive analysis, the Kruskal-Wallis test, and ordinal logistic regression were used to assess awareness levels and their determinants. Results: Among the 753 respondents, 15.5% of respondents reported very high awareness, 18.7% reported fairly high awareness, 32.1% reported moderate awareness, 27.2% reported somewhat low awareness, and 6.5% reported complete unawareness. Acceptance levels were distributed as follows: 20.3% strongly in favour, 24.7% somewhat in favour, 45.9% neutral, 7.3% somewhat opposed, and 1.9% strongly opposed. Higher awareness was significantly associated with younger age, higher household living standard, receiving a recommendation from medical personnel, and participation in vaccine education programs (all p < 0.05). Acceptance was significantly influenced by age, residence type (urban community, town center, or rural), medical personnel recommendation, educational campaign participation, and perceived affordability of vaccine cost (all p < 0.05). Conclusions: Overall, Shanghai residents exhibited suboptimal awareness and acceptance of non-NIP vaccines, with a clear "high acceptance but low knowledge" phenomenon. To improve awareness, strategies should include strengthening healthcare providers' recommendations and implementing systematic educational campaigns. To enhance acceptance, efforts should focus on disseminating positive, evidence-based information; reinforcing provider guidance; expanding outreach and education; and optimizing payment mechanisms to improve economic accessibility.