Vaccines最新文献

{"title":"SARS-CoV-2 Infection or COVID-19 mRNA Vaccination Elicits Partially Different Spike-Reactive Memory B Cell Responses in Naïve Individuals.","authors":"Lingling Yao, Noémi Becza, Georgia Stylianou, Magdalena Tary-Lehmann, Stephen M Todryk, Greg A Kirchenbaum, Paul V Lehmann","doi":"10.3390/vaccines13090944","DOIUrl":"10.3390/vaccines13090944","url":null,"abstract":"<p><p><b>Background:</b> The COVID-19 pandemic provided a unique opportunity to evaluate how the human immune system responded to a novel pathogen and to determine whether immune responses initiated through natural infection differ from those elicited by vaccination against the same antigen. Here, we provide a comprehensive analysis of SARS-CoV-2 Spike (S-antigen)-reactive memory B cells (B_mem) elicited in previously immunologically naïve subjects following their first infection with the original Wuhan-Hu-1 (WH1)-like strain or their initial COVID-19 mRNA prime-boost regimen encoding the same WH1-S-antigen. In particular, we tested the hypothesis that the primary encounter of SARS-CoV-2 S-antigen in lung mucosal tissues during infection vs. intramuscular COVID-19 mRNA injection would elicit different B_mem responses. <b>Methods:</b> Cryopreserved peripheral blood mononuclear cell (PBMC) samples collected following primary infection with the WH1 strain or completion of the initial prime-boost vaccination regimen were tested in ImmunoSpot^® assays to assess the frequency, Ig class/subclass usage, and cross-reactivity of the S-antigen-reactive B_mem compartment; pre-pandemic blood draws served as naïve controls. <b>Results</b>: The B_mem repertoires generated post-infection vs. post-vaccination were found to be quite similar but with some subtle differences. In both cases, the prevalent induction of IgG1-expressing B_mem in similar frequencies was seen, ~30% of which targeted the receptor binding domain (RBD) of the WH1-S-antigen. Also, the extent of cross-reactivity with the future Omicron (BA.1) RBD was found to be similar for both cohorts. However, IgA⁺ B_mem were preferentially induced after infection, while IgG4⁺ B_mem were detected only after vaccination. <b>Conclusions:</b> B_mem elicited in naïve human subjects following SARS-CoV-2 infection or after WH1-S encoding mRNA vaccination were only subtly different, although the relevance of these differences as it relates to immune protection warrants further investigation. Our findings serve to illustrate the usefulness and feasibility of performing comprehensive monitoring of antigen-specific B cell memory in larger cohorts using the ImmunoSpot^® technique.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474496/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145179037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-Polio Syndrome: Impact of Humoral Immune Deficiencies, Poliovirus Neutralizing Antibodies, Vitamin D Deficiency.","authors":"Antonio Toniolo, Konstantin Chumakov, Giovanni Federico, Giuseppe Maccari, Angelo Genoni, Alessandro Saba, Andrea Nauti, Giorgio Bono, Franco Molteni, Salvatore Monaco","doi":"10.3390/vaccines13090939","DOIUrl":"10.3390/vaccines13090939","url":null,"abstract":"<p><p><b>Background/Objectives</b>: This study investigated susceptibility factors that may contribute to Post-Polio Syndrome (PPS) in elderly polio survivors. <b>Methods</b>: Serum immunoglobulin (Ig) levels, poliovirus neutralizing antibodies (PV NAb), and vitamin D status were evaluated in 80 PPS patients, 40 family members, and 89 healthy controls. <b>Results</b>: A significant number of PPS patients and their family members showed reduced levels of total IgG and/or IgA, and specific IgG subclasses, indicating a high prevalence of primary humoral immunodeficiencies within these groups. Despite these Ig deficits, PV NAb titers were similar across all groups, indicating high protection against poliovirus, likely due to vaccination campaigns with live virus in Italy and intense exposure to poliovirus, especially in long-term rehabilitation institutions. However, a small group of PPS subjects lacked neutralizing antibodies for specific poliovirus serotypes, suggesting more severe antibody deficiencies. Additionally, PPS subjects had a high prevalence of vitamin D deficiency, which likely increases their risk for osteoporosis/osteopenia and fractures. It is unclear if this deficiency was also present in their infancy, potentially enhancing their susceptibility to poliovirus. <b>Conclusions</b>: Overall, the findings indicate that genetic, immunological, or nutritional factors may increase individual susceptibility to the pathogenic effects of poliovirus. This study-limited to serum antibodies-highlights the complex relationship between immune status and long-term health in aging polio survivors. The results emphasize the need for potent poliovirus drugs and vaccines to help contain possible outbreaks but also-for poliomyelitis survivors-to avoid or mitigate the progression to PPS, the latest phase of this devastating disease.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474101/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Online Conference \"Chronic Viral Infections and Cancer, Openings for Vaccines and Cure\" VIRCAN2024, Monitoring the Progress.","authors":"Liba Sokolovska, Juris Jansons, Franco M Buonaguro, Maria Isaguliants","doi":"10.3390/vaccines13090940","DOIUrl":"10.3390/vaccines13090940","url":null,"abstract":"<p><p>Chronic viral infections and virus-induced cancers have been actively studied for decades, with many significant advancements in basic science, disease cure, treatment, and prevention. Yet, today, these infections and pathologies remain major contributors to morbidity and mortality worldwide. The international online conference \"VIRCAN2024: Chronic viral infections and cancer, openings for Vaccines and Cure\" aimed to address the remaining issues, present the research carried out in this broad field, and prognose directions for its development. The conference covered oncogenicity mechanisms and new approaches in the development of treatments and vaccines. VIRCAN2024 was held on the platform of Riga Stradins University, Riga, Latvia. The conference was supported by the Latvian Science Council grant \"Human papillomavirus genome associated correlates of disease progression and treatment response for cervical neoplasms and cancer\", and the scientific journal <i>Vaccines</i> (MDPI). This report summarizes the lectures and presentations given at the conference.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474226/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Public Health in the Headlines: A Study of Media Behavior on Discourses on Vaccination During COVID-19.","authors":"Carolina Jann Scalfoni, Edson Theodoro Dos Santos Neto, Tatiana Breder Emerich","doi":"10.3390/vaccines13090937","DOIUrl":"10.3390/vaccines13090937","url":null,"abstract":"<p><strong>Background/objectives: </strong>The COVID-19 pandemic was characterized by the rapid transmission of the virus and a global race for vaccines, with vaccines such as AstraZeneca, CoronaVac, Pfizer, and Janssen arriving in Brazil in 2020. Concurrently, an infodemic of information, driven by the media and social media, highlighted the importance of health communication. This study examines how online newspapers in a Brazilian state disseminated information about vaccination and its relationship with vaccine adherence among the population.</p><p><strong>Methods: </strong>Quantitative research, in which a total of 5308 journalistic articles were verified, using two databases, one for the publication of journalistic articles and the other for vaccinations in the state, which applied 9,577,567 doses in the period.</p><p><strong>Results: </strong>The analyses demonstrated a positive correlation between the number of publications of articles and the number of applications of vaccines (rho = 0.407, <i>p</i>-value < 0.0005), revealing a relationship of both increase and decrease in the publication of newspaper articles and the application of vaccines in specific weeks during the analysis period. Vaccination data revealed low adherence to the booster dose by the population, with unequal values among the cities of the state.</p><p><strong>Conclusions: </strong>The study highlighted the potential importance of newspapers in disseminating information about vaccines during the pandemic, underscoring the need for regional health strategies to increase vaccination coverage.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474228/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic Regulation of Influenza Vaccine Responses in Racially Diverse Hispanics.","authors":"Daniela Frasca, Maria Romero, Suresh Pallikkuth","doi":"10.3390/vaccines13090938","DOIUrl":"10.3390/vaccines13090938","url":null,"abstract":"<p><strong>Background: </strong>Racial and ethnic differences in vaccine responses, particularly within Hispanic populations, remain underexplored. Disparities in immune function may be influenced by metabolic and inflammatory mechanisms.</p><p><strong>Methods: </strong>The current study investigated humoral immune responses to influenza vaccination in a diverse cohort of Hispanic individuals from South Florida, encompassing both White and Black Hispanics. Antibody responses were assessed post-vaccination, and B cell phenotypes were analyzed to evaluate inflammatory and metabolic characteristics. In vitro experiments were conducted to determine whether blocking metabolic pathways could alter the inflammatory phenotype of B cells. Data were analyzed using an unpaired Student's <i>t</i>-test (two-tailed), and correlation analysis was conducted with Pearson correlation.</p><p><strong>Results: </strong>Our findings indicated that Black Hispanic individuals exhibited significantly reduced antibody responses compared to White Hispanics (<i>p</i> < 0.01) following influenza vaccination. This diminished humoral response correlated with inversely with serum LDH (r = -0.58; <i>p</i> = 0.0005) and other intrinsic inflammatory phenotypes in blood-derived B cells and was supported by changes in metabolic activity. In vitro blockade of metabolic pathways effectively reduced the inflammatory phenotype of B cells from Black Hispanic individuals, suggesting a mechanistic link between metabolic dysfunction and impaired vaccine-induced immunity.</p><p><strong>Conclusion: </strong>This study is the first to reveal racial disparities in influenza vaccine responses within a Hispanic population, highlighting reduced antibody production in Black Hispanics. These findings suggest that metabolically driven B cell inflammation may play a critical role and point to potential therapeutic strategies to address disparities in vaccine-induced immunity.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474446/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antibody-Dependent Cellular Cytotoxicity Elicited by the Antibodies Against the E120R Protein of African Swine Fever Virus.","authors":"Shengmei Chen, Jing Lan, Zhanhao Lu, Jia Li, Caoyuan Ma, Rui Luo, Qiang Fu, Yuan Sun, Tao Wang, Hua-Ji Qiu","doi":"10.3390/vaccines13090934","DOIUrl":"10.3390/vaccines13090934","url":null,"abstract":"<p><p><b>Background/Objectives:</b> African swine fever (ASF) is a disease of domestic pigs and wild boar caused by African swine fever virus (ASFV), in which infection often leads to high morbidity and mortality. Although subunit and mRNA vaccines based on protective antigens have been explored for ASFV, their protective efficacy remains insufficient for practical ASF control, highlighting the need to identify new potential antigens capable of inducing more potent and broadly protective immune responses. Previously, we found that the antibodies against the ASFV E120R protein (pE120R) could significantly inhibit virus replication in primary porcine alveolar macrophages (PAMs). However, it is not yet known whether anti-pE120R antibodies can induce antibody-dependent cellular cytotoxicity (ADCC). <b>Methods:</b> In this study, we analyzed the conservation and immunogenic features of pE120R and established an HEK293T cell line with stable expression of pE120R as target cells (HEK293T-pE120R). Additionally, a co-culture system comprising target cells and peripheral blood mononuclear cells (PBMCs) was established to evaluate the ability of the anti-pE120R antibodies to induce ADCC as measured by lactate dehydrogenase (LDH) release assays. <b>Results:</b> The results showed that pE120R is highly conserved among different ASFV genotypes and contains multiple B-cell and T-cell epitopes. Importantly, LDH release assays demonstrated that anti-pE120R antibodies triggered NK cell-mediated ADCC. Notably, ASFV replication in HEK293T-pE120R cells was not promoted. <b>Conclusions:</b> In summary, pE120R was associated with antibody production in a cytotoxicity assay. The ability of this antigen to induce protective immunity, if any, requires further evaluation <i>in vivo</i>.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474280/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Humoral Response to the Third Dose of SARS-CoV-2 Vaccine Among Dialysis Patients: A Breakthrough Infection Case-Control Study.","authors":"Francesca Colavita, Concetta Castilletti, Giulia Matusali, Silvia Accordini, Salvatore De Masi, Roberto Da Cas, Natasha Gianesini, Giovanni Baglio, Massimo Francalancia, Giuseppe Traversa, Flavia Chiarotti, Silvia Meschi, Elvira Bianco, Mario Salomone, Alfonso Mele, Piergiorgio Messa, Carmine Zoccali, Francesca Menniti Ippolito, The COVIDVaxDia Study Group","doi":"10.3390/vaccines13090935","DOIUrl":"10.3390/vaccines13090935","url":null,"abstract":"<p><p><b>Background:</b> COVID-19 vaccination and subsequent booster doses became critical components of public health strategies to control the pandemic and reduce disease severity, especially in fragile individuals. Among these, subjects undergoing dialysis represent one of the highly vulnerable populations. <b>Methods:</b> We conducted a multicenter case-control study among dialysis patients between March 2021 and May 2022 (study population n = 3264). We evaluated anti-S/RBD-IgG and anti-SARS-CoV-2 neutralizing antibodies before (T3) and after (T4) the third dose in individuals with a COVID-19 diagnosis after the third dose (cases) and in those who did not report infection (controls). <b>Results:</b> The study included 187 cases and 150 controls. Serological analysis showed a significant increase (<i>p</i> < 0.001) in anti-SARS-CoV-2 antibody levels after the third vaccine dose (from T3 to T4) in both groups. At T3, with the same number of days between the second dose and T3, the antibody levels detected were significantly lower in cases as compared to controls. At T4, we observed similar antibody titers in the two groups. Notably, the mean difference in time from the third dose to T4 was significantly greater in controls (73.0 days vs. 36.7, <i>p</i> < 0.001), suggesting a reduced antibody waning in controls. Accordingly, multivariate analysis showed that the risk of infection was considerably reduced by the pre-third-dose antibody levels. <b>Conclusions:</b> This study reinforces the critical role of the humoral response in preventing infections in the vulnerable population of dialysis patients. Regular monitoring of antibody levels and timely administration of booster doses are essential to optimize protection in this group.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474067/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chronic Diseases and Influenza Vaccines.","authors":"Rui Lian, Hongbo Zhang, Youcai An, Ze Chen","doi":"10.3390/vaccines13090936","DOIUrl":"10.3390/vaccines13090936","url":null,"abstract":"<p><strong>Background: </strong>Chronic illnesses pose a major global health challenge with an estimated 1.56 billion people affected worldwide in 2025, and 85% of these being older adults facing at least one chronic condition. These patients are particularly vulnerable to severe influenza complications and higher mortality rates due to weakened immune responses; in addition, vaccination rates in China remain significantly lower than those in developed nations.</p><p><strong>Methods: </strong>This review examines how chronic conditions exacerbate influenza-related effects through immune dysfunction and metabolic imbalances, and how influenza infection worsens chronic diseases by triggering inflammation, suppressing immunity, and causing secondary infections that lead to respiratory complications, cardiac complications, and blood sugar disturbances.</p><p><strong>Results: </strong>A bidirectional adverse interaction exists in which chronic illnesses increase influenza severity via poor immunity, while influenza accelerates chronic disease progression (e.g., cardiac events and diabetic ketoacidosis). Vaccination reduces hospitalization by 32-52% in patients with lung disease and mortality by 16-46% in diabetic patients, with good safety.</p><p><strong>Conclusions: </strong>The findings emphasize the urgent need for improved vaccination strategies in patients with chronic diseases. Such strategies are crucial to reducing disease burden, enhancing clinical outcomes, and improving quality of life, while also providing critical evidence for the development of public health policies.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474285/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immunomodulation of Patients with Canine Visceral Leishmaniasis at Different Stages: A 12-Month Follow-Up Study Using LaSap.","authors":"Kelvinson Fernandes Viana, Adrieli Barboza de Souza, Sara Torres, Maria Camila Escobar Garcia, Açucena Veleh Rivas, Alex Sander Rodrigues Cangussu, Francisca Hildemagna Guedes da Silva, Rodolfo Cordeiro Giunchetti","doi":"10.3390/vaccines13090933","DOIUrl":"10.3390/vaccines13090933","url":null,"abstract":"<p><p><b>Background/Objectives</b>: Canine visceral leishmaniasis (CVL) is one of the main neglected protozoan diseases in the world. Dogs play a fundamental role in the maintenance of <i>Leishmania infantum</i> in the Americas, and we have already encountered resistance problems with drugs currently used in these animals. <b>Methods</b>: In view of this, two new immunotherapeutic protocols were tested in 48 dogs, using <i>L. amazonensis</i> antigens plus saponin (LaSap) and only <i>L. amazonensis</i> antigens (La) as a control group. Dogs naturally infected with <i>L. infantum</i> were divided into four groups, according to clinical staging. A total of 24 dogs (stages 1 and 2) received a four-dose protocol, and another 24 dogs (stages 3 to 5) received six doses. All animals received a booster dose every three months until they were one year old. <b>Results</b>: Our results showed that dogs in the early stages of the disease respond better and are able to remain stable for longer, maintaining baseline laboratory biomarkers, in addition to having a lower parasite load. <b>Conclusions</b>: On the other hand, dogs in more advanced stages have a poor response, with stage 3 being a key point in clinical progression or regression.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474320/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Immunization Strategies in Pediatric Patients Receiving Hematopoietic Cell Transplantation (HCT) and Chimeric Antigen Receptor T-Cell (CAR-T) Therapy: Challenges and Insights from a Narrative Review.","authors":"Daniele Zama, Laura Pedretti, Gaia Capoferri, Roberta Forestiero, Marcello Lanari, Susanna Esposito","doi":"10.3390/vaccines13090932","DOIUrl":"10.3390/vaccines13090932","url":null,"abstract":"<p><strong>Background: </strong>Hematopoietic cell transplantation (HCT) and chimeric antigen receptor T-cell (CAR-T) therapy have markedly improved survival in pediatric patients with hematological malignancies. However, these treatments cause profound immunosuppression, leading to significant susceptibility to vaccine-preventable diseases (VPDs), including invasive pneumococcal disease and measles. Timely and tailored immunization strategies are crucial to mitigate infectious risks in this vulnerable population.</p><p><strong>Methods: </strong>We conducted a narrative review of the English-language literature from 2000 to 2024, including clinical guidelines, surveys, and original studies, to evaluate immune reconstitution and vaccination practices in pediatric patients undergoing HCT and CAR-T therapy. Literature searches in PubMed, Scopus, and Web of Science used disease-specific, therapy-specific, and pathogen-specific terms. Data synthesis focused on vaccine schedules, immune recovery markers, and adherence challenges.</p><p><strong>Results: </strong>Profound immune deficits post-HCT and CAR-T therapy compromise both innate and adaptive immunity, often necessitating revaccination. Key factors influencing vaccine responses include time since therapy, graft source, immunosuppressive treatments, and chronic graft-versus-host disease. Although inactivated vaccines are generally safe from three to six months post-HCT, live vaccines remain contraindicated until documented immune recovery. CAR-T therapy introduces unique challenges due to prolonged B-cell aplasia and hypogammaglobulinemia, leading to delayed or reduced vaccine responses. Despite established guidelines, real-world adherence to vaccination schedules remains suboptimal, driven by institutional, logistic, and patient-related barriers.</p><p><strong>Conclusions: </strong>Effective vaccination strategies are essential for reducing infectious morbidity in pediatric HCT and CAR-T recipients. Personalized vaccine schedules, immune monitoring, and multidisciplinary coordination are critical to bridging gaps between guidelines and practice, ultimately improving long-term outcomes for immunocompromised children.</p>","PeriodicalId":23634,"journal":{"name":"Vaccines","volume":"13 9","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12474115/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145178794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}