Search Results (420)

Down Syndrome (DS) is the most common chromosomal abnormality characterized by neurodevelopmental impairment. Apart from maternal age, its risk factors remain poorly understood. This prospective case-control study aimed to evaluate the role of maternal anti-zona pellucida (ZP) antibodies (Ab) and anti-thyroid-Ab in predicting DS. Correlations of anti-ZP-Ab and anti-thyroid-Ab with maternal age were also assessed. Anti-ZP-Ab were measured after childbirth using ELISA. Anti-thyroid peroxidase (aTPO) and anti-thyroglobulin (aTgII) antibodies were also analysed with the Allelica IM platform. Statistical analyses included receiver operating characteristic curve assessment, expressed as area under the curve (AUC) and linear regression modeling. Between September 2020 and October 2022, 58 women were enrolled. Anti-ZP-Ab levels were significantly higher in women with DS pregnancy with an odds ratio adjusted for maternal age of 71.52 (95% CI: 7.05–725.18) and an excellent predictive performance (AUC = 0.94; 95% CI: 0.88–1.00). For optical density levels > 1, the accuracy was 89.7% (95% CI: 78.2–100.0). No statistically significant differences were observed for aTPO and aTgII. Neither Anti-ZP-Ab nor anti-thyroid antibodies increased with age. These findings suggest that Anti-ZP-Ab are strongly associated with DS risk, suggesting a potential age-independent autoimmune contribution to trisomy 21. Their evaluation may support preconception counseling, especially for women aged > 35 years. Future studies could clarify causality and define the role of maternal autoimmunity in DS etiology. Full article

Background: Presence of milk, fruits, eggs, fish, nuts and wheat antigens in the amniotic fluid is described in the literature. Studies show a contradictory relationship between maternal exposure to allergens and early sensitization of the fetus to allergens. Hemochorionic type of the human placenta allows for easier transfer of nutrients and antibodies from the mother’s blood to the fetal circulation through the direct contact of maternal blood with the fetal chorion. During the third trimester of pregnancy, immunoglobulin G (IgG) is actively transferred through the placenta into the fetal via neonatal FcRN receptor (FcRN). In addition, monomeric immunoglobulin E (IgE) cannot cross the placenta Aim: The objective of our study is to track intrauterine sensitization to essential food proteins at birth in umbilical cord blood in mothers with established peripheral blood eosinophilia and in their infants using allergen-specific IgE and IgG. Methods: An observational study was carried out in a cohort of 22 mothers with eosinophilia and their babies. Differences in expression between groups were assessed. Blood samples were collected to determine serum IgE and IgG specific to a set of inhalant and food allergens. Results: We did not find a significant correlation between specific IgE to cow’s milk (p = 0.857), egg white (p = 0.926) and egg yolk (p = 0.096) in umbilical cord blood and maternal blood samples taken immediately before birth. Spearman’s correlation of the specific IgE and IgG in umbilical cord blood showed no dependence between the two variables. In contrast, statistical analysis showed that maternal eosinophilia in peripheral blood could be a risk factor for the development of allergy in the offspring (χ², p = 0.0347). However, given the small number of patients, this claim needs to be confirmed with further studies. Conclusions: Due to the functional immaturity of the developing immune system of the fetus, the generation and maintenance of an independent immune response to allergens are incomplete. Maternal IgG (specific) passes to the baby and high maternal IG to a specific allergen reduces babies IgE production. In addition, low maternal specific IgG may promote IgE production in the baby under the influence of microenvironmental factors (cytokine background). The main limitation of our study is the small number of patients. Further research is needed in this direction to clarify the mechanisms and risk factors for early sensitization in newborns. Full article

The endemicity of H9N2 avian influenza viruses (AIVs), particularly the Y280 lineage, poses persistent challenges to the poultry industry due to the limitations of inactivated vaccines, such as interference by maternally derived antibodies (MDAs) and incomplete suppression of viral replication. This study evaluated the immunogenicity and protective efficacy of a novel recombinant turkey herpesvirus vaccine expressing the hemagglutinin gene of H9N2/Y280 (rHVT-H9/Y280) in commercial Hy-Line Brown layers with high-MDA backgrounds. In a comparative challenge study, the rHVT-H9/Y280 vaccine induced complete protection against a homologous Y280 strain challenge at 4 weeks of age, whereas commercial inactivated vaccines failed to completely block replication, showing virus isolation rates of 16.7–25%. Long-term serological monitoring demonstrated that the rHVT-H9/Y280 vaccine elicited a robust humoral response characterized by persistent maintenance of high HI titers (>8.0 log₂) up to 39 weeks post-vaccination. These findings confirm that rHVT-H9/Y280 effectively overcomes MDA interference and provides protection by inhibition of viral replication in layer chickens, making it a promising candidate for the effective control of H9N2 AIV in endemic regions. Full article

Background: Feto-maternal hemorrhages (FMHs) due to placenta disruption and bleeding from fetal maternal circulation can lead to life-threatening fetal anemia. These hemorrhages are more often of small volume and remain unreported. Sensitization to fetal red blood cell (RBC) antigens can occur during pregnancy, at delivery, or after invasive procedures. The sensitized mother produces IgG antibodies (abs) that cross the placenta and cause the hemolysis of fetal RBCs, release of hemoglobin, and increased levels of unconjugated bilirubin in the fetus or neonate. The result is hemolytic disease of the fetus and newborn (HDFN). Methods: In this study, we aim to provide a structured overview of RBC alloimmunization in pregnancy. A literature search was conducted using PubMed. English articles published from January 2010 to October 2025 were selected by the authors. The contributing manuscripts focused on managing RBC alloimmunization in pregnancy, FMH screening and quantification, antenatal and postnatal testing, Rh immune globulin (Rh Ig or Anti-D) prophylaxis, and national registry data. Results: Frequencies of RBC abs vary among American, Caucasian, and Asian populations because of genetic diversity, different antibody detection and antibody identification methods, and FMH tests. More specifically, the erythrocyte rosette is a simple screening test for FMH. A positive rosette must be quantified by the Kleihauer–Betke (KB) or flow cytometry (FC). The KB results may be overestimated or underestimated. The advantages of FC include high accuracy, specificity, and repeatability. Ultimately, anti-D prophylaxis protocol varies from country to country. Conclusion: Maternal alloimmunization is an uncommon and highly variable event. Although introducing anti-D prophylaxis has decreased the Rh immunization rate, it is still an unmet medical need. In brief, mitigation strategies for RBC alloimmunization risk include accurate maternal and neonatal testing at different time points, adequate Rh immune globulin prophylaxis in D-negative pregnant women, preventing sensitizing events, adopting a conservative transfusion policy, and upfront ABO and Rh (C/c, E/e) and Kell matching in females under 50 years of age. Full article

Background: Despite the availability of a killed whole-virus (KV) vaccine, diarrhea caused by equine rotavirus group A (ERVA) remains a significant health concern for foals in the United States. The vaccine is administered to pregnant mares, with foals protected by passive transfer of colostral antibodies. However, KV-induced immunity is only partially protective and maternal antibody levels in foals are often low and wane rapidly. To address these limitations, we developed a mRNA-based ERVA vaccine encoding the highly conserved VP8* protein to evaluate whether it can provide improved immune protection. Methods: Pregnant mares (n = 12 per group) were immunized either at months 8 and 10 of gestation with the VP8* mRNA or at months 8, 9, and 10 of gestation with the KV. Serum samples were collected from mares before and after immunization and from their foals at ages 1, 35, and 49 days. Serum samples were tested by indirect ELISA for VP8*-specific relative antibody concentrations and relative concentrations were compared for effects of study group and sample-time using linear mixed-effects regression. To detect functional antibodies against ERVA, a virus neutralization titer assay was performed to compare titers between mares vaccinated with the mRNA vaccine (and their foals) and unvaccinated control mares (and their foals). Results: Mares vaccinated with VP8* mRNA had significantly (p < 0.05) higher antibody concentrations after foaling than mares in the KV group, and foals of VP8* mRNA-vaccinated mares had significantly (p < 0.05) higher concentrations through age 49 days than foals in the KV group. In addition, the VP8* mRNA vaccine elicited higher titers of ERVA-neutralizing antibodies against both G3 and G14 strains. Conclusions: Longer-lasting, higher concentrations of virus-neutralizing antibodies might provide superior duration of immunity to ERVA in foals from mares vaccinated with VP8* mRNA. Full article

Background: Non-typhoidal Salmonella (NTS) is a major foodborne pathogen, with poultry products, especially eggs, being the primary source of human infections. Current serovar-specific poultry vaccines effectively reduce targeted Salmonella serovars but may inadvertently promote the emergence of untargeted serovars within poultry flocks. Therefore, novel vaccine candidates providing broad cross-serovar protection are needed to improve overall effectiveness of Salmonella control programs. Objectives: This study evaluated the immunogenicity of the novel subunit vaccine candidate InvG and assessed its ability to reduce Salmonella colonization in vaccinated laying hens and their progeny through maternally derived antibodies transferred via egg yolk. Methodology: Three experiments were performed. Experiment I evaluated the immunogenicity of purified recombinant InvG by (a) measuring anti-InvG antibodies using an enzyme-linked immunosorbent assay (ELISA) and (b) completing transcriptomic profiling of immune responses in vaccinated chickens. Vaccinated chickens were subsequently challenged with Salmonella Enteritidis to assess the efficacy of anti InvG antibodies in reducing intestinal colonization of Salmonella. Experiment II involved immunizing hens with InvG, to evaluate passive transfer of antibodies via egg yolk and the protective efficacy of maternally derived antibodies against Salmonella challenge. Passive transfer was assessed by measuring IgY antibodies in hen serum, egg yolk, and progeny serum, as well as secretory IgA (sIgA) antibodies in progeny intestinal washings using ELISA. Protective efficacy was evaluated by orally challenging one-day-old chicks with three different Salmonella serovars. Experiment III assessed the persistence of anti-InvG antibodies in the serum of vaccinated hens and their transfer into eggs following two doses of InvG. Results: InvG vaccination induced robust IgY antibody responses in hens, with efficient maternal antibody transfer to progeny via egg yolk. A statistically significant reduction in Salmonella colonization was observed in both vaccinated hens and their progeny. Conclusions: These findings demonstrate that InvG represents a promising subunit vaccine candidate for Salmonella control in poultry and warrants further investigation towards development as a broadly protective commercial poultry vaccine against Salmonella. Full article

Background: A quadrivalent HPV vaccine (BPV) has been developed to prevent diseases caused by HPV types 6, 11, 16, and 18 for the first time in Iran. The BPV is composed of the papillomavirus major capsid protein L1, which serves as the primary target in the design of the prophylactic HPV vaccines. To enhance immunogenicity, BPV was formulated with an amorphous aluminum hydroxy phosphate sulfate adjuvant. Methods: The immunogenicity and safety of BPV were assessed through analyses of both humoral and cell-mediated immunity, single and repeated doses, and reproductive effects using animal models. Results: Acute toxicity assessments showed no abnormalities in ophthalmic examinations, biochemical profiles, hematological parameters, and gross pathology findings. Additionally, no mortality or abnormal clinical signs were observed during a 90-day repeated-dose toxicity study. While some inflammatory reactions were noted at the injection sites and in the liver tissues of BPV-treated groups, these reactions were resolved by day 90 after the initial BPV administration. Furthermore, no signs of toxicity were detected in F1 offspring, and no adverse effects were identified in maternal reproductive performance, fertility, or hematological or biochemical parameters throughout the study duration. The BPV candidate successfully induced T-cell proliferation and increased the proportions of CD₃⁺ CD₄⁺ and CD₃⁺ CD₈⁺ T cells. It also stimulated the secretion of both interferon gamma (IFN-γ) and interleukin-4 (IL-4) cytokines in splenocytes isolated from animal models after the third dose. Moreover, anti-HPV L1 IgG antibody production was confirmed on day 14 after administration of each of the three BPV vaccine doses. Conclusions: The findings suggest that BPV is a vaccine candidate that stimulates both cellular and humoral immunity and demonstrate its safety profile in animal models. Full article

Background/Objectives: Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection in young children, especially during infancy, resulting in substantial morbidity and mortality. Methods: Acknowledging the real-world evidence on RSV immunization, the College of Pediatrics, Academy of Medicine of Malaysia, has appointed an expert panel to develop a position paper on recommendations for infant and/or maternal vaccination against childhood RSV, specifically in the Malaysian context with year-round RSV activity. Results: Recognizing the potential constraints and limitations in the implementation process, the expert panel recommends targeted immunization with long-acting RSV monoclonal antibody (mAb) for high-risk infants as a pragmatic first step, with subsequent scale-up to universal immunization of infants when resources permit. Conclusions: Immunization is the most effective strategy to prevent RSV-related lower respiratory tract infection in childhood. Year-round maternal vaccination between 28 and 36 weeks’ gestation, combined with immunization at six months for all infants, may potentially circumvent the unclear seasonality. Full article

Human respiratory syncytial virus (RSV) remains a leading cause of severe lower respiratory tract infections in infants and immunocompromised populations, causing approximately 160,000 annual deaths globally. Despite recent approvals of prefusion F (pre-F) protein-based vaccines (Arexvy, Abrysvo) for older adults and pregnant women, pediatric vaccine development faces unique challenges including enhanced respiratory disease (ERD) risks, maternal antibody interference, and immature infant immune responses. Meanwhile, G protein glycosylation variability and NS1/NS2-mediated interferon suppression remain the outstanding difficulties in structure-based vaccine design. Additionally, current animal models demonstrate notable constraints in virus replication, host susceptibility, immune responses, clinical symptoms, and ERD phenomena. This review synthesizes current obstacles and innovative strategies, highlighting that the selection of multi-antigen strategies, appropriate adjuvants, and the development of more precise preclinical animal models are critical elements that will determine the efficacy and safety of future RSV vaccines. Full article

Background: Children with congenital heart disease (CHD) are at substantially increased risk for respiratory infections, which occur more frequently and with greater severity than in healthy peers. This heightened vulnerability stems from multifactorial immune impairment, including defects in innate and adaptive immunity, chronic inflammation related to abnormal hemodynamics and hypoxia, reduced thymic function, and genetic syndromes affecting both cardiac and immune development. Viral pathogens—particularly respiratory syncytial virus (RSV), influenza viruses, and SARS-CoV-2—account for most infections, although bacterial pathogens remain relevant, especially in postoperative settings. Methods: This narrative review summarizes current evidence on infection susceptibility in children with CHD, the epidemiology and clinical relevance of major respiratory pathogens, and the effectiveness of available preventive measures. Literature evaluating immunological mechanisms, infection burden, vaccine effectiveness, and passive immunization strategies was examined, along with existing national and international immunization guidelines. Results: Children with CHD consistently exhibit higher rates of hospitalization, intensive care unit admission, mechanical ventilation, and mortality following respiratory infections. RSV, influenza, and SARS-CoV-2 infections are particularly severe in this population, while bacterial infections, though less common, contribute substantially to postoperative morbidity. Preventive options—including routine childhood vaccines, pneumococcal and Haemophilus influenzae type b vaccines, influenza vaccines, COVID-19 mRNA vaccines, and RSV monoclonal antibodies—demonstrate strong protective effects. New long-acting RSV monoclonal antibodies and maternal vaccination markedly enhance prevention in early infancy. However, vaccine coverage remains insufficient due to parental hesitancy, provider uncertainty, delayed immunization, and limited CHD-specific evidence. Conclusions: Respiratory infections pose a significant and preventable health burden in children with CHD. Enhancing the use of both active and passive immunization is essential to reduce morbidity and mortality. Strengthening evidence-based guidelines, improving coordination between specialists and primary care providers, integrating immunization checks into routine CHD management, and providing clear, condition-specific counseling to families can substantially improve vaccine uptake and clinical outcomes in this vulnerable population. Full article

During their early life, puppies are protected against infectious agents with the presence of maternal derived antibodies (MDA). Vaccination is recommended to start as soon as the levels of MDA begin to wane to ensure that the puppy’s immune system can respond effectively to the vaccines and develop active immunity against diseases. Two studies were designed to assess the efficacy of the Canigen^TM DHPPi vaccine in puppies from 6 weeks of age. The studies comprised two parts: the efficacy assessment of the Canine Parainfluenza Virus (CPiV) vaccine component against a virulent challenge with CPiV (Experiment A) and an immunogenicity assessment of Canine Distemper Virus (CDV), Canine Adenovirus (CAV-2), and Canine Parvovirus (CPV-2) vaccine components (Experiment B). In Experiment A, twelve puppies were immunized with two injections of Canigen^TM DHPPi (at minimum titer) two weeks apart and twelve control puppies received the vaccine diluent. All animals were challenged with a virulent, heterologous CPiV strain two weeks after the second vaccination. Vaccinated puppies exhibited a significant reduction in nasal viral shedding compared to the control group. Clinical signs of respiratory disease were mild and transient in both groups. In Experiment B, six puppies were immunized with two injections of Canigen^TM DHPPi (at minimum titer) two weeks apart. A follow-up of the seroneutralizing antibodies titers against the CDV, CAV-2 and CPV-2 vaccine components was performed in order to assess the efficacy on the serological response basis. After the first vaccine injection, all the puppies seroconverted and presented seroneutralizing antibody titers reaching a protective thresholds against CDV (≥10^0.82), CAV-2 and CAV-1 (≥10^0.82), CPV-2 and CPV-2c (≥10^1.8). After the second vaccine injection, a more robust immune response was observed and the seroneutralizing antibody titers remained high until 4 weeks post vaccination for those three vaccine components. In both experiments (A and B), all vaccinated animals remained in good health, with no adverse reactions recorded during the vaccination phase. As a conclusion, the efficacy of the Canigen^TM DHPPi vaccine was demonstrated when administered in dogs from 6 weeks of age. These results fully support the interest of an early vaccination in such young puppies followed by the recommended vaccination scheme. Full article

Background: Complete fetal atrioventricular block (CAVB) is a rare but life-threatening condition, occurring in approximately 1–2% of pregnancies associated with maternal anti-Ro/SSA antibodies. The transplacental migration of anti-Ro/SSA and anti-La/SSB antibodies damages the fetal cardiac system, leading to sustained bradycardia, cardiomyopathy, fetal hydrops, and intrauterine fetal demise. Despite the use of fluorinated corticosteroids or β-agonists, therapeutic efficacy remains limited once a complete block is established. Case Presentation: We present the case of a 35-year-old primigravida with a pregnancy achieved through in vitro fertilization (IVF). At 20 weeks of gestation, she was referred to our emergency unit due to persistent fetal bradycardia. Fetal echocardiography confirmed CAVB with a ventricular rate of 64 bpm. Maternal serologic testing was positive for anti-Ro/SSA and anti-La/SSB antibodies, suggesting an autoimmune etiology. Treatment with oral dexamethasone and salbutamol was initiated, but follow-up echocardiography at 24 weeks showed worsening cardiac status, including reduced ventricular rate of 59 bpm, cardiomegaly, and pericardial effusion. Intrauterine fetal death occurred at 25 weeks of gestation. Management and Outcome: Four months postpartum, the patient underwent a minor salivary gland biopsy. Histopathological evaluation confirmed the diagnosis of primary Sjögren’s syndrome. Conclusions: This case illustrates the severe consequences of autoimmune-mediated CAVB and the limited effectiveness of available treatments once a complete block has developed. It underscores the importance of early fetal rhythm surveillance and targeted maternal autoimmune screening—particularly before assisted reproduction, where structured preconception evaluation offers an opportunity for earlier recognition and risk stratification. Earlier detection may improve counseling and management strategies in future pregnancies. Full article

Antimicrobial resistance (AMR) is an increasing concern in food animal production. In swine herds, viral infections often lead to secondary bacterial disease and higher antimicrobial use (AMU). This study describes how U.S. swine veterinarians view the role of viral vaccines in reducing this reliance on antimicrobials. We conducted a national survey of swine practitioners and follow-up semi-structured interviews with a subset of respondents. Across participants, porcine reproductive and respiratory syndrome (PRRS), swine influenza (SIV), and rotaviral enteritis were most often named as viral diseases in urgent need of improved vaccines. These diseases cause substantial economic losses and frequently trigger AMU in commercial herds. Veterinarians reported several recurring challenges with current vaccines, including limited cross-protection against field strains, interference from maternally derived antibodies, and short duration of protection. Despite these limitations, most respondents supported vaccination as a key tool to curb AMU and indicated they would accept higher prices for clearly improved products. These findings reveal both a clear need and specific opportunities for future vaccine development to provide broader and more reliable protection, reduce AMU, and help slow the development of AMR. Full article

Kittens are born with some maternally derived antibodies (MDA) that, together with maternal gut microbiota, bring some form of early defense against pathogens. However, this protection declines and the rapid changes and challenges the kitten typically encounters can adversely affect their health. Nutrition can modulate the immune system and gut microbiota, offering a boost to protection following weaning. This controlled, randomized, double-blinded study tests a dietary supplement containing nucleotides, oligosaccharides, vitamin E and β-carotene in 50 domestic short-haired kittens. Control kittens were fed standard, dry kitten diet whilst test kittens received the same diet with supplement for 52 weeks. Kittens received routine vaccinations and blood samples were collected throughout the study for standard hematology, serum antibodies and cytokine expression. Rectal fecal samples were analyzed for gut microbiota via 16S rRNA gene sequencing. Supplemented kittens showed significantly improved antibody response to Chlamydia vaccine at various timepoints versus controls, with no consistent effects of supplementation on responses to other vaccines. Several cytokines were significantly influenced by the supplement, which also significantly altered gut microbiota diversity. In conclusion, a dietary supplement was shown to promote immune response and gut microbiota changes in kittens and may help to support a healthy transition into adulthood. Full article

Background/Objectives: HIV-exposed uninfected (HEU) infants experience increased severe respiratory syncytial virus lower respiratory tract illness (RSV-LRTI) rates compared with HIV-unexposed infants. Maternal bivalent RSVpreF vaccination can prevent infant RSV-LRTI but data from HEU infants are lacking. Methods: This phase 3 randomized, double-blinded trial assessed RSVpreF safety and immunogenicity in pregnant participants from South Africa living with HIV and their infants. Maternal participants with stable HIV disease taking antiretroviral therapy received RSVpreF or placebo (24–36 weeks’ gestation). Primary safety endpoints included reactogenicity through 7 days after vaccination (maternal participants), adverse events (AEs) through 1 month after vaccination (maternal participants) or birth (infants), and serious AEs (SAEs) throughout the study (maternal participants) or through 6 months after birth (infants). Immune responses were evaluated by 50% RSV-A and RSV-B neutralizing titers prevaccination and at delivery (maternal participants) or birth (infants). Results: Overall, 343 maternal participants received RSVpreF (n = 172) or placebo (n = 171). Most reactogenicity events were mild/moderate. AEs and SAEs were generally reported at similar frequencies in maternal RSVpreF and placebo groups including percentages of hypertensive disorders of pregnancy. There were no safety concerns in infants; percentages of reported AEs and SAEs were generally similar between RSVpreF and placebo groups and no difference in preterm birth. RSVpreF elicited high maternal neutralizing RSV-A and RSV-B immune responses, with efficient RSV antibody transplacental transfer to infants demonstrated by levels greater than the placebo group at birth (geometric mean ratios (GMRs) of RSVpreF to placebo were 7.8 for RSV-A and 6.8 for RSV-B) and by comparison with a cohort of HIV-unexposed infants from the pivotal phase 3 efficacy trial (GMRs of HEU to HIV-unexposed infants were 0.86 for RSV-A and 0.72 for RSV-B). Conclusions: These results support maternal RSVpreF vaccination among those living with stable HIV for preventing RSV-LRTI in HEU infants. (NCT06325657). Full article