Vaccines

13 pages, 2067 KiB

Open AccessArticle

Immunogenicity of Rabies Virus G-Protein mRNA Formulated with Muscle-Targeting Lipid Nanoparticles in Mice

by Qin Li, Huarong Bai, Xueliang Yu, Qiang Liu and Rongkuan Hu

Vaccines 2025, 13(3), 217; https://doi.org/10.3390/vaccines13030217 (registering DOI) - 22 Feb 2025

Background: Rabies is a preventable zoonotic disease caused by the rabies virus (RABV) with a high mortality rate. Most vaccines on the market or under development have issues, such as low single-dose neutralization titer, complex processes, and high costs. During the COVID-19 pandemic, [...] Read more.

Background: Rabies is a preventable zoonotic disease caused by the rabies virus (RABV) with a high mortality rate. Most vaccines on the market or under development have issues, such as low single-dose neutralization titer, complex processes, and high costs. During the COVID-19 pandemic, the successful development of mRNA vaccines opened up a new avenue for preventive vaccines. As a new technology, mRNA has higher scalability. Methods: In this study, we designed an mRNA encoding the RV-G protein, encapsulated by our own muscle-targeting lipid nanoparticles (LNPs), and evaluated the expression of the RV-G protein in vitro, its immunogenicity, and its protection against virus infection in vivo. Results: The results show that RV-G mRNA was significantly expressed in vitro. High Virus-IgG binding titers and virus-neutralizing antibody titers (VNT) were induced by immunization with RV-G mRNA-LNP. Additionally, our results showed that the RV-G mRNA vaccine is better than commercially available vaccines in mice. Conclusions: Our research highlights the potential of the mRNA-LNP platform in developing next-generation rabies vaccines. Full article

(This article belongs to the Special Issue mRNA Vaccines: Pioneering the Future of Vaccination)

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20 pages, 1952 KiB

Open AccessArticle

Simian Immunodeficiency Virus-Based Virus-like Particles Are an Efficient Tool to Induce Persistent Anti-SARS-CoV-2 Spike Neutralizing Antibodies and Specific T Cells in Mice

by Alessandra Gallinaro, Chiara Falce, Maria Franca Pirillo, Martina Borghi, Felicia Grasso, Andrea Canitano, Serena Cecchetti, Marco Baratella, Zuleika Michelini, Sabrina Mariotti, Maria Vincenza Chiantore, Iole Farina, Antonio Di Virgilio, Antonella Tinari, Gabriella Scarlatti, Donatella Negri and Andrea Cara

Vaccines 2025, 13(3), 216; https://doi.org/10.3390/vaccines13030216 - 21 Feb 2025

Abstract

Background/Objectives: Virus-like particles (VLPs) represent an attractive platform for delivering vaccine formulations, combining a high biosafety profile with a potent immune-stimulatory ability. VLPs are non-infectious, non-replicating, self-assembling nanostructures that can be exploited to efficiently expose membrane-tethered glycoproteins such as the SARS-CoV-2 Spike (S) [...] Read more.

Background/Objectives: Virus-like particles (VLPs) represent an attractive platform for delivering vaccine formulations, combining a high biosafety profile with a potent immune-stimulatory ability. VLPs are non-infectious, non-replicating, self-assembling nanostructures that can be exploited to efficiently expose membrane-tethered glycoproteins such as the SARS-CoV-2 Spike (S) protein, the main target of approved preventive vaccines. Here, we describe the development and preclinical validation of Simian Immunodeficiency Virus (SIV)-based GFP-labeled VLPs displaying S from the B.1.617.2 (Delta) variant (VLP/S-Delta) for inducing persistent anti-SARS-CoV-2 neutralizing antibodies (nAbs) and S-specific T cell responses in mice. Methods: SIV-derived VLP/S-Delta were produced by co-transfecting a plasmid expressing SIVGag-GFP, required for VLP assembly and quantification by flow virometry, a plasmid encoding the Delta S protein deleted in the cytoplasmic tail (CT), to improve membrane binding, and a VSV.G-expressing plasmid, to enhance VLP uptake. Recovered VLPs were titrated by flow virometry and characterized in vitro by transmission electron microscopy (TEM) and confocal microscopy (CLSM). BALB/c mice were immunized intramuscularly with VLP/S-Delta following a prime–boost regimen, and humoral and cellular immune responses were assessed. Results: VLP/S-Delta were efficiently pseudotyped with CT-truncated S-Delta. After BALB/c priming, VLP/S-Delta elicited both specific anti-RBD IgGs and anti-Delta nAbs that significantly increased after the boost and were maintained over time. The prime–boost vaccination induced similar levels of cross-nAbs against the ancestral Wuhan-Hu-1 strain as well as cross-nAbs against Omicron BA.1, BA.2 and BA.4/5 VoCs, albeit at lower levels. Moreover, immunization with VLP/S-Delta induced S-specific IFNγ-producing T cells. Conclusions: These data suggest that SIV-based VLPs are an appropriate delivery system for the elicitation of efficient and sustained humoral and cellular immunity in mice, paving the way for further improvements in the immunogen design to enhance the quality and breadth of immune responses against different viral glycoproteins. Full article

(This article belongs to the Collection COVID-19 Vaccines and Vaccination)

11 pages, 1099 KiB

Open AccessArticle

Antibody Persistence of Human Diploid Cell Rabies Vaccine Administrated Using the Four-Versus Five-Dose Essen Intramuscular Regimen in Post-Exposure Prophylaxis: A Prospective Cohort Study Among the Chinese Population

by Linlin Wu, Yu Zhang, Zhuoying Huang, Hongmei Lu, Xiaojun Li, Qi Zhu, Chunli Yin, Jiechen Liu, Huiyong Shao and Xiaodong Sun

Vaccines 2025, 13(3), 215; https://doi.org/10.3390/vaccines13030215 - 21 Feb 2025

Abstract

Objective: Evidence on long-term antibody persistence for the rabies vaccine administered using the four-dose Essen regimen is lacking. This study compared antibody persistence for the human diploid cell rabies vaccine (HDCV) administered using the four- versus five-dose Essen intramuscular regimen in post-exposure prophylaxis [...] Read more.

Objective: Evidence on long-term antibody persistence for the rabies vaccine administered using the four-dose Essen regimen is lacking. This study compared antibody persistence for the human diploid cell rabies vaccine (HDCV) administered using the four- versus five-dose Essen intramuscular regimen in post-exposure prophylaxis (PEP). Methods: This prospective cohort study enrolled patients vaccinated with the lyophilized HDCV for PEP who were grouped into four-dose and five-dose Essen groups. Rabies virus-neutralizing antibody (RVNA) detection was performed at 1 year or 3 years after initial vaccination. Results: In total, 180 and 184 patients were included in the four- and five-dose groups, respectively. The 1-year seroconversion (>0.5 IU/mL) rates were similar in the five-dose and four-dose Essen groups (99.2% vs. 98.3%, p = 0.662), as were the 3-year seroconversion rates (98.4% vs. 98.3%, p > 0.999). The median RVNA titer was significantly higher with the five-dose Essen regimen compared with the four-dose Essen regimen at 1 year (2.75 vs. 4.6 IU/mL, p = 0.002), and both groups had similar rates at 3 years (2.00 vs. 3.80 IU/mL, p = 0.443). Multivariable stepwise linear regression analysis showed that the five-dose Essen regimen was independently associated with higher serum RVNA titer compared to the four-dose Essen regimen (β = 0.175, p = 0.001), and 3 years after vaccination, was independently associated with a lower serum RVNA titer compared to 1 year (β = −1.06, p = 0.049). Conclusions: The four- and five-dose Essen regimens effectively produce durable immunogenicity, supporting the feasibility of implementing the four-dose Essen regimen for rabies immunization in China. Full article

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8 pages, 177 KiB

Open AccessArticle

Do We Have a Common Understanding of How Vaccine Policy Affects Health Equity? Evaluating Variability in the Advisory Committee on Immunization Practices’ Equity Assessment

by Kathleen Dooling, Elif Alyanak, Dial Hewlett, Haley Payne, Vincenza Snow, Mitchell Finkel, Maura Burns, Brett Hauber, Joshua Coulter and Ronika Alexander-Parrish

Vaccines 2025, 13(3), 214; https://doi.org/10.3390/vaccines13030214 - 21 Feb 2025

Abstract

Background/Objectives: The Advisory Committee on Immunization Practices’ (ACIP) Evidence to Recommendation (EtR) Framework has assessed vaccine equity, in addition to clinical and epidemiological data, since 2020. The domain’s use has not yet been evaluated. Methods: Authors assessed web-published, Equity domain-inclusive ACIP Work Group [...] Read more.

Background/Objectives: The Advisory Committee on Immunization Practices’ (ACIP) Evidence to Recommendation (EtR) Framework has assessed vaccine equity, in addition to clinical and epidemiological data, since 2020. The domain’s use has not yet been evaluated. Methods: Authors assessed web-published, Equity domain-inclusive ACIP Work Group EtR presentations occurring between October 2020 and October 2023. Domain judgments were scored and assigned variability ratings based on the number and spread of domain categories selected. Equity domain trends were evaluated using sample statistics and one- and two-way analyses of variance. Results: Of the 44 assessed EtRs, 27 (61.4%) had variable judgments for at least one domain; 9 (20.4%) had variable Equity judgments. Across domains, Values had the greatest variability, followed by Equity. Across disease targets, EtRs assessing products for RSV prevention were most variable. Pediatric product EtRs had greater variability than adult products, and EtRs resulting in shared clinical decision-making (SCDM) recommendations had greater variability than those resulting in routine recommendations. Conclusions: Values and Equity domains judgment imprecision highlights a need for additional clarity to support consistent assessment. Full article

10 pages, 687 KiB

Open AccessBrief Report

XBB1.5-Adapted COVID-19 Vaccine Acceptance Among Dialysis and Kidney Transplant Patients: A Bi-National Survey Study

by Georg Beilhack, Rossella Monteforte, Florian Frommlet, Alicia Faltum, Timna Agur and Ruth Rahamimov

Vaccines 2025, 13(3), 213; https://doi.org/10.3390/vaccines13030213 - 21 Feb 2025

Abstract

Background: A decrease in governmental vaccination initiatives and diminishing public enthusiasm for vaccines could jeopardize vaccine uptake, potentially endangering those who are most at risk. In this survey study, we evaluated the current acceptance rates of the newly developed monovalent XBB1.5-adapted COVID-19 [...] Read more.

Background: A decrease in governmental vaccination initiatives and diminishing public enthusiasm for vaccines could jeopardize vaccine uptake, potentially endangering those who are most at risk. In this survey study, we evaluated the current acceptance rates of the newly developed monovalent XBB1.5-adapted COVID-19 vaccine among kidney transplant recipients and dialysis patients in Austria and Israel and identified factors influencing vaccine acceptance. Methods: The survey involved a total of 656 patients aged 18 and older and was carried out from 20 November to 21 December 2023, at the Medical University of Vienna, Austria and the Rabin Medical Center in Petah Tikva, Israel. Logistic regression analysis was used to explore the relationships between vaccine acceptance and variables such as age, gender, country, past COVID-19 infection status and severity, renal replacement therapy, education level, and willingness to receive the annual flu vaccine. Results: The survey showed that 54% of patients in Austria and 63% in Israel expressed acceptance of the modified XBB1.5-adapted COVID-19 vaccine. The main hesitancy was due to concerns about potential side effects, with 44% in Austria and 53% in Israel expressing apprehension. A willingness to receive the influenza vaccine, older age in Austria, and kidney transplant status in Israel were key predictors of greater COVID-19 vaccine acceptance. Conclusions: This study showed that more than 50% of our kidney transplant recipients and dialysis patients were willing to receive the adapted COVID-19 vaccine. Yet, vaccine hesitancy remained a significant barrier even among these high-risk groups, despite the availability of an updated COVID-19 vaccine targeting the Omicron subvariant XBB1.5. Full article

(This article belongs to the Section COVID-19 Vaccines and Vaccination)

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25 pages, 8147 KiB

Open AccessArticle

The Potential Public Health Impact of the Adjuvanted Respiratory Syncytial Virus Prefusion F Protein Vaccine Among Older Adults in Italy

by Anna Puggina, Filippo Rumi, Eleftherios Zarkadoulas, Alen Marijam and Giovanna Elisa Calabró

Vaccines 2025, 13(3), 212; https://doi.org/10.3390/vaccines13030212 - 20 Feb 2025

Abstract

Background: Respiratory syncytial virus (RSV) is a common cause of acute respiratory infection (ARI). The risk of severe RSV outcomes is higher among older adults (OAs) and individuals with chronic diseases (high risk, HR). AS01_E-adjuvanted RSV preFusion protein 3 OA vaccine [...] Read more.

Background: Respiratory syncytial virus (RSV) is a common cause of acute respiratory infection (ARI). The risk of severe RSV outcomes is higher among older adults (OAs) and individuals with chronic diseases (high risk, HR). AS01_E-adjuvanted RSV preFusion protein 3 OA vaccine (adjuvanted RSVPreF3 OA is approved for the prevention of lower respiratory tract disease [LRTD] due to RSV in OAs). The objective of this study was to assess the potential public health impact of an RSV vaccination program using adjuvanted RSVPreF3 OA in adults ≥75 years (y) and HR adults ≥60 y in Italy. Methods: A static multi-cohort Markov model was used to estimate the number of RSV cases and associated health outcomes projected in adults ≥75 y and HR adults ≥60 y with no RSV vaccination or with a single dose of adjuvanted RSVPreF3 OA. Epidemiological, healthcare resource use and cost data were obtained from the scientific literature. Vaccine efficacy and waning inputs were based on results from the AReSVi-006 phase III clinical trial. Several scenarios for vaccine coverage were explored. Results: Assuming the target vaccination rate for influenza vaccination in Italy (75%), the model predicted that vaccinating Italian adults ≥75 y and the HR population ≥ 60 y with adjuvanted RSVPreF3 OA would reduce the number of RSV-LRTD events by 43%, leading to a reduction in associated emergency department visits, hospitalizations, complications, deaths, and direct healthcare costs over a 3-year period. Conclusions: The vaccination of Italians aged ≥ 75 y and HR individuals aged ≥ 60 y using the adjuvanted RSVPreF3 OA vaccine has the potential to offer substantial public health benefits by reducing the burden of RSV disease. Full article

(This article belongs to the Special Issue Estimating Vaccines' Value and Impact)

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18 pages, 1968 KiB

Open AccessArticle

A Novel Prototype African Swine Fever Virus DIVA (Differentiation Between Infected and Vaccinated Animals) Serological Assay Based on the Detection of Antibodies Against the pEP153R, eGFP, and p72 Proteins

by Gabriela González-García, Carmina Gallardo, Mercedes Montón, Sandra Barroso-Arévalo, Nadia Casado, José Ángel Barasona, José Manuel Sánchez-Vizcaíno, Ángel Venteo, Patricia Sastre and Paloma Rueda

Vaccines 2025, 13(3), 211; https://doi.org/10.3390/vaccines13030211 - 20 Feb 2025

Abstract

Background/Objectives: African Swine Fever (ASF) is one of the most significant infectious diseases affecting both domestic pig and wild boar populations, leading to substantial economic and biosanitary consequences. In Europe, disease management relies on stringent biosecurity measures and surveillance through diagnosis, highlighting the [...] Read more.

Background/Objectives: African Swine Fever (ASF) is one of the most significant infectious diseases affecting both domestic pig and wild boar populations, leading to substantial economic and biosanitary consequences. In Europe, disease management relies on stringent biosecurity measures and surveillance through diagnosis, highlighting the urgent need for an effective and safe vaccine for ASF control. In this context, the VACDIVA project has generated several promising vaccine candidates, including those with the EP153R gene deleted and replaced by the eGFP reporter gene. Methods: In this study, pEP153R and eGFP proteins were produced using recombinant technology and demonstrated their antigenicity and DIVA capability through indirect ELISA. Additionally, a prototype serological DIVA test was designed and developed. The assay is based on the detection of antibodies against both DIVA antigens and the well-established immunogenic p72 protein. Results: This preliminary DIVA diagnostic assay complements vaccine candidates based on a genotype II ASFV strain, featuring the deletion of the EP153R gene and/or the insertion of the eGFP reporter gene, exemplified by the Lv17/WB/Rie1-∆CD vaccine candidate. Conclusions: This approach could potentially improve surveillance during prospective vaccination campaigns. Full article

(This article belongs to the Special Issue Vaccine Development for Swine Viral Pathogens)

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11 pages, 408 KiB

Open AccessArticle

Epidemiology and Clinical Features of Mpox in Jakarta, Indonesia, August 2022–December 2023

by Hanny Nilasari, Eliza Miranda, Melani Marissa, Ani Ruspitawati, Dwi O. T. L. Handayani, Ngabila Salama, Budi Setiawan, Supriadi, Tiranti V. Aisyah, Inggariwati, Arif S. Haq, Siti Zuhroh, Eka Y. Safitri, Rahmat A. Pramono, Inggrita Wisnuwardani, Erni J. Nelwan, Robert Sinto, Adityo Susilo, Yulia R. Saharman, Suratno L. Ratnoglik, Ni L. P. Pitawati, Muhammad Fauzan, Sekar S. A. Hasanah, Megandhita Sharasti and Evy Yunihastuti Show full author list Hide full author list

Vaccines 2025, 13(3), 210; https://doi.org/10.3390/vaccines13030210 - 20 Feb 2025

Abstract

Background/Objective: This study explores the epidemiology and clinical features of re-emerging mpox in Jakarta, Indonesia. Methods: This study used a retrospective study design to describe the epidemiological data, clinical features, and mortality of mpox patients from August 2022 to December 2023. In addition, [...] Read more.

Background/Objective: This study explores the epidemiology and clinical features of re-emerging mpox in Jakarta, Indonesia. Methods: This study used a retrospective study design to describe the epidemiological data, clinical features, and mortality of mpox patients from August 2022 to December 2023. In addition, this study also aims to identify the differences in both the epidemiology and clinical features of mpox in people living with HIV (PLHIV) and in non-HIV patients (non-PLHIV). Results: Our study shows that, as of the end of December 2023, 59 mpox cases were treated in Jakarta. All of the mpox cases in Jakarta were diagnosed in males, mainly found in MSM (91.5%), and PLHIV (78%). Most patients would manifest with fever, rash, and skin lesions. Syphilis was found as a concomitant infection in this group (22/59, 37.2%). Severe manifestations were found among PLHIV without antiretroviral therapy (ART). Conclusions: Mpox cases in Jakarta were all found in males and most of them were PLHIV. There are various manifestations of mpox; however, since immunosuppressed patients could present differently, a strong surveillance and vaccine notification system, cautious management, and spreading vaccination awareness are needed to prevent and treat mpox. Full article

(This article belongs to the Special Issue Strategies for the Monitoring, Treatment, and Prevention of Mpox and Other Poxvirus Infections)

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13 pages, 226 KiB

Open AccessArticle

A Candidate Ac₃-S-LPS Vaccine Against S. flexneri 1b, 2a, 3a, 6, and Y Activates Long-Lived Systemic and Mucosal Immune Responses in Healthy Volunteers: Results of an Open-Label, Randomized 2 Clinical Trial

by Vladimir A. Ledov, Victor V. Romanenko, Marina E. Golovina, Biana I. Alkhazova, Alexander L. Kovalchuk and Petr G. Aparin

Vaccines 2025, 13(3), 209; https://doi.org/10.3390/vaccines13030209 - 20 Feb 2025

Abstract

Objectives: Determination of reactogenicity and immunogenicity of a pentavalent candidate vaccine against S. flexneri 1b, 2a, 3a, 6, and Y (PLVF). Methods: The study involved 80 healthy adult volunteers aged 18–55 years. Groups were subcutaneously immunized twice at a 30-day interval with 62.5 μg/0.5 [...] Read more.

Objectives: Determination of reactogenicity and immunogenicity of a pentavalent candidate vaccine against S. flexneri 1b, 2a, 3a, 6, and Y (PLVF). Methods: The study involved 80 healthy adult volunteers aged 18–55 years. Groups were subcutaneously immunized twice at a 30-day interval with 62.5 μg/0.5 mL or 125 μg/0.5 mL of the vaccine. Results: During the entire 8-month period of post-vaccination observation, the vaccine was well tolerated, with no local or systemic reactions detected objectively. The results of laboratory studies demonstrated no effect on the main indicators of hemogram, biochemical blood test, or urinalysis. IgA, IgG, and IgM levels against LPS S. flexneri 1b, 2a, 3a, 6, and Y were examined before vaccination, a month after each vaccination, and 6 months after booster vaccination. One month after vaccination, IgA and IgG seroconversions were observed in 67.5–82.5% (depending on serotype) and 60–77.5% of volunteers, respectively. Booster immunization did not have a significant effect on vaccine immunogenicity. In two separate groups of 15 and 9 volunteers for mucosal sIgA, IgA, and IgG titer determination after immunization with a 125 μg vaccine dose, paired stool, and saliva samples were taken before and one month after vaccination. In 26.7–40% of volunteers, there was a 2-fold and higher increase in sIgA titer for the studied serotypes in the feces and in 66.7–88.9% in saliva. IgA and IgG 2-fold conversion rates were 26.7–53.3% and 33.3–46.7% in the feces, 33.3–77.9%, and 66.7–77.8% in saliva, respectively. Conclusions: the tolerability of PLVF and the pronounced humoral immune response allow us to proceed to the phase 3 clinical trial stage. Full article

(This article belongs to the Special Issue Recent Scientific Advances in Vaccines for Shigella)

19 pages, 1626 KiB

Open AccessArticle

Impact of COVID-19 Vaccination on Cardiac Function and Survival in Maintenance Hemodialysis Patients

by Xiao Tu, Tingfei He, Bing Xu, Jiazhen Yin, Fangyu Yi, Ye Li, Jinchi Gao, Peng Bi, Wanyue Xu, Rihong Hu, Lidan Hu and Yayu Li

Vaccines 2025, 13(3), 208; https://doi.org/10.3390/vaccines13030208 - 20 Feb 2025

Abstract

Maintenance hemodialysis patients are at increased risk of cardiovascular complications and mortality following COVID-19 infection due to compromised immune function. This study aims to evaluate the impact of the COVID-19 vaccine (CoronaVac) on cardiac function and survival in this population. Background/Objectives: We [...] Read more.

Maintenance hemodialysis patients are at increased risk of cardiovascular complications and mortality following COVID-19 infection due to compromised immune function. This study aims to evaluate the impact of the COVID-19 vaccine (CoronaVac) on cardiac function and survival in this population. Background/Objectives: We aimed to examine whether CoronaVac vaccination affects heart function and survival rates in maintenance hemodialysis patients. Specifically, we assessed changes in heart ultrasound (echocardiographic) measurements, B-type natriuretic peptide (BNP) levels, and survival outcomes by comparing vaccinated and unvaccinated patients. Methods: A retrospective analysis was conducted on 531 maintenance hemodialysis patients, including 79 who received CoronaVac and 452 who did not. We compared the pre- and post-infection changes in heart function (echocardiographic parameters) and BNP levels between the two groups and assessed their association with the survival rates. Results: The vaccinated patients were younger (60.54 ± 13.51 vs. 65.21 ± 13.76 years, p = 0.006) and had shorter dialysis durations (56.04 ± 51.88 vs. 73.73 ± 64.79 months, p = 0.022). The mortality rate was also significantly lower in the vaccinated group (6.33% vs. 14.38%, p = 0.049). After infection, the unvaccinated patients showed significant declines in heart function and increased B-type natriuretic peptide levels, while the vaccinated patients demonstrated no significant deterioration. Older age, coronary artery disease, inflammation levels, and heart abnormalities were identified as the key risk factors for mortality. Conclusions: CoronaVac was linked to lower mortality and better heart function in maintenance hemodialysis patients. The vaccine may help to reduce infection severity, lower strain on the heart, and improve the overall prognosis. Full article

(This article belongs to the Section COVID-19 Vaccines and Vaccination)

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Vaccines, Volume 13, Issue 3 (March 2025) – 10 articles

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