Search Results (292)

Background: Human papillomavirus (HPV) has traditionally been considered a sexually transmitted infection, yet accumulating evidence demonstrates that HPV can be acquired through multiple non-sexual routes. Understanding these alternative transmission pathways is critical for interpreting HPV detection in non-sexually active populations and for refining public health strategies. Methods: This review synthesizes current evidence on non-sexual HPV transmission routes, including vertical (transplacental, intrapartum), perinatal oropharyngeal colonization, fomite contamination, breast milk transmission, and horizontal non-sexual contact. We examine HPV prevalence data from female virgins, neonates, infants, and children, and evaluate metagenomic evidence positioning HPV as a component of the human virome across multiple body sites. Results: Published studies report that vertical transmission occurs in approximately 18.2% of HPV-positive mothers, with neonatal HPV positivity of 3.4% at birth and 100% genotype concordance in transmission pairs. Transplacental transmission has been documented in 10.2% of concordant mother–placenta–newborn triads. Reviewed studies report oropharyngeal colonization at birth reaching 58.2% following vaginal delivery, with 94.3% of colonized neonates clearing infection by 24 months. HPV DNA has been detected on fomites and medical devices, in breast milk (8.6–15%), and across body sites in healthy adults (skin 61.3%, vagina 41.5%, oral cavity 30%, gut 17.3%). Metagenomic studies identify HPV DNA in 68.9% of healthy individuals, with 109 distinct types detected. Female virgins show HPV prevalence ranging from 0–51.1% across studies. Conclusions: The reviewed evidence suggests that HPV exhibits characteristics of a ubiquitous virome component with multiple non-sexual acquisition routes. These findings have important implications for vaccination strategies, screening interpretation, infection control in healthcare settings, and counseling of pediatric cases and non-sexually active individuals. Full article

Background: Buffaloes have a significant share in the agricultural economies of many developing countries; however, the industry is not well-established because of the low reproductive efficiency of buffaloes. In this study, we designed a novel strategy to enhance buffalo reproductive efficiency and examined the significance of intramuscular AMH-INH-RFRP DNA vaccine immunization on reproductive performance. Methods: Allocated into four groups (n = 30/group), female buffaloes (aged 5–8 years, n = 120) were randomly enrolled in the study. Treatment groups received 10 mL of AMH-INH-RFRP DNA vaccine intramuscularly, once daily for three consecutive days, at the following concentrations: T1—3 × 10⁸ CFU/mL, T2—3 × 10⁹ CFU/mL, and T3—3 × 10¹⁰ CFU/mL. All vaccinated groups received a booster vaccination two weeks later, while the control group received 10 mL of phosphate-buffered saline (PBS) intramuscularly on the same schedule. Serum antibody titers against anti-Müllerian hormone (AMH), inhibin (INH), and RF-amide-related peptide (RFRP) were quantified using indirect ELISA on days 14 (post-primary immunization) and 28 (post-booster immunization). Results: Following primary immunization, antibody titers against AMH, INH, and RFRP were significantly higher in the T3 group than in the T1 group (p < 0.05), and booster immunization further increased antibody positivity rates. Serum concentrations of IL-4, IFN-γ, and E₂ were significantly elevated in the T2 and T3 groups compared to the control group (p < 0.05), while P₄ levels showed no significant differences among groups. Ultrasonography revealed that the ovulatory follicle diameter and dominant follicle growth rate were significantly increased in the T2 and T3 groups compared to the control and T1 groups (p < 0.05). The estrus rate was significantly higher in the T3 group than in the control group (76.67% vs. 40.00%, p < 0.05), and ovulation rates were significantly higher in the T2 (83.33%) and T3 (86.67%) groups compared to the control group (56.67%) (p < 0.05). However, conception rates did not differ significantly between vaccinated and control groups in the primary dose comparison (p > 0.05). In exploratory post hoc analyses, antibody-positive (Ab+) buffaloes exhibited higher E₂ concentrations, larger ovulatory follicle diameters, accelerated dominant follicle growth rates, and higher estrus and ovulation rates compared to antibody-negative (Ab−) buffaloes. Furthermore, gestating buffaloes were monitored until calving, revealing no significant effect of the vaccine on newborn calf weight or body size. Conclusions: In total, intramuscular immunization with the AMH-INH-RFRP DNA vaccine, particularly at the highest dose, enhances reproductive performance in buffaloes by stimulating E₂ secretion and follicular development. Full article

Respiratory syncytial virus (RSV) remains a major cause of severe lower respiratory tract infection in early infancy, a period characterized by immunological immaturity and limited capacity for effective antiviral responses. Maternal RSV vaccination has emerged as a successful strategy to protect newborns by inducing high concentrations of IgG1-dominant, prefusion F-specific antibodies, which are selectively and actively transported across the placenta. This review synthesizes current mechanistic insights into how maternally derived antibodies confer neonatal protection, focusing on (i) FcRn-mediated transplacental transport, (ii) IgG subclass-specific differences in transfer and half-life, and (iii) the role of Fc glycosylation in modulating Fcγ receptor engagement and effector functions. Beyond neutralization, vaccine-induced antibodies mediate Fc-dependent mechanisms such as antibody-dependent cellular cytotoxicity and phagocytosis, which may be preferentially enriched in the neonatal circulation. Although emerging systems serology data suggest qualitative selectivity in placental transfer, evidence remains heterogeneous and highlights the need for further clarification of glycosylation-dependent and glycosylation-independent pathways. The timing of vaccination, maternal antibody characteristics, and placental integrity critically influence neonatal antibody levels and the duration of passive immunity. Understanding these molecular determinants is essential for optimizing maternal RSV immunization strategies and improving early-life protection. Full article

Background: Maternal influenza during the peripartum period poses a clinically significant risk to newborns, particularly for infants younger than 6 months. This group is especially vulnerable because of immune immaturity and the absence of an approved influenza vaccine for this age group. In light of emerging influenza virus mutations with pandemic potential, current protocols require evaluation with respect to infection prevention. Objective: To map and synthesize the available evidence and recommendations on the management of neonates born to mothers with suspected or confirmed influenza, with particular focus on delivery, skin-to-skin contact, breastfeeding, mother–infant separation, and neonatal antiviral therapy. Sources of Evidence: We performed a scoping review of the literature and professional guidance documents addressing the perinatal and postnatal management of newborns exposed to maternal influenza, using PubMed, Google Scholar, Web of Science, Embase, WHO, and CDC publications. The available evidence was synthesized narratively across the principal domains of clinical care. Conclusions: Current evidence does not support changing the mode of delivery solely because of maternal influenza. When the mother’s clinical condition permits, rooming-in, skin-to-skin contact, and breastfeeding can generally be supported with strict droplet precautions and hand hygiene. These practices provide substantial benefits for bonding, nutrition, and passive immune protection. Temporary separation may be considered in selected cases of severe maternal illness, although consistent evidence of benefit is limited. In neonates with suspected or confirmed influenza, early antiviral treatment should be considered in accordance with current pediatric guidance, whereas routine chemoprophylaxis in infants younger than 3 months remains insufficiently supported by evidence. Overall, recommendations remain heterogeneous, highlighting the need for higher-quality studies and clearer neonatal care pathways. Full article

Background/Objectives: Globally, coverage of the hepatitis B vaccine within 24 h of birth is 45 percent, far below the WHO target of 90 percent by 2030. For newborns delivered in out-of-facility settings, delayed contact with health workers, transportation barriers, and cold chain constraints can impede timely vaccination. This review explores strategies and facilitators for delivering birth dose vaccines to infants born outside of health facilities in low- and middle-income countries. Methods: A rapid scoping review was conducted, searching PubMed and targeted websites for peer-reviewed and gray literature published between 2005 and 2025. Data were charted using a standardized extraction tool. Frequency and thematic analyses were conducted. Results: After screening 315 studies, 26 eligible sources were identified. Delivery strategies consisted of three components: identifying and tracking home births; supporting caregiver uptake through education, reminders, or incentives; and delivering the vaccine through home-based administration or referral to facilities. Sub-components included pregnancy and birth notification systems, postnatal home visits, mobile reminders, incentives, and home-based vaccination by facility or community providers. The feasibility of these strategies was shaped by factors across system levels, such as national policies and financing; health system infrastructure; cold chain capacity; health workforce configuration; caregiver awareness; and community social norms. In several contexts, flexible cold chain approaches and vaccine administration by community-based cadres enabled timely vaccination of infants born at home. Conclusions: Vaccination programs can learn from existing out-of-facility vaccine delivery approaches to strengthen hepatitis B birth dose vaccination programs for timely and equitable coverage. Full article

Senecavirus A (SVA) is a newly emerging picornavirus associated with porcine idiopathic vesicular disease and sudden death in newborn piglets. Currently, no specific vaccines or drugs are available against SVA, highlighting the importance of investigating the immunological characteristics of its key proteins. The VP1 protein of SVA exhibits strong immunogenicity and high sequence conservation, and it is indispensable to the viral life cycle. In the present study, a monoclonal antibody (mAb) against VP1 was generated. A series of truncated VP1 proteins was then expressed to precisely map the epitope recognized by this mAb. The minimal reactive unit was identified as ¹⁶DTDFSGELA²⁴. Homology analysis further revealed that this epitope is conserved among different SVA isolates deposited in GenBank. Moreover, AlphaFold prediction, along with PyMOL (Version 3.0.3) and GETAREA analyses, reveals that this epitope resides in the α-helix and loop regions of the three-dimensional structure of the VP1 protein and is surface-exposed. Collectively, these findings indicate that the mAb and its recognized epitope represent valuable tools for investigating SVA etiology and VP1 protein function. Full article

Background. Newborn ruminants are born agammaglobulinemic, and colostrum quality (IgG concentration) is often insufficient, especially in heifers, leading to high morbidity and mortality from diarrheal infections. Objective. To develop and evaluate colostrum enrichment with specific egg yolk immunoglobulins (IgY) for the prevention of diarrhea in newborn calves. Methods. Hens were hyperimmunized with an inactivated vaccine against rotavirus, coronavirus, and E. coli. Yolk melange was prepared. Total and specific IgY were measured by chromatography and ELISA. Trials were conducted in three farms with high diarrhea incidence: experimental calves (n = 25) received 100 mL of melange (5 yolks) with the first two colostrum feedings; controls (n = 25) received native colostrum. Results. One yolk contained up to 100 mg of polyclonal IgY, with 8% specific antibodies. Diarrhea occurred in 12% of experimental calves (mild, no drugs) vs. 76% in controls (24% required antibiotics/rehydration). Testing in two other farms (n = 42, n = 38) reduced incidence 5.2–6.8-fold compared to the previous period. Conclusions. Enriching colostrum with specific IgY from hyperimmunized hens is highly effective and affordable for preventing diarrheal infections in newborn calves, especially in herds with poor colostrum quality in heifers. Full article

Background: Lower respiratory tract infections remain a major cause of morbidity and mortality in infants worldwide. Newborns possess an immature immune system but acquire passive immunity through maternal antibodies transferred via the placenta (IgG) and breast milk (IgA). Maternal vaccination may enhance this protection. This study aimed to quantify antibody levels against respiratory viruses in serum and breast milk from lactating women. Methods: Serum and breast milk samples were collected from 26 lactating mothers. Antibody levels were measured using an indirect enzyme-linked immunosorbent assay (ELISA) targeting seven viral antigens: influenza A (A/Thailand, A/California), influenza B (B/Phuket, B/Austria), SARS-CoV-2 (Spike and receptor-binding domain, RBD) and RSV F pre-fusion protein. Antibody isotypes IgG, IgA and IgM were analysed. Results: Virus-specific IgG and IgA antibodies were detected in all samples. Breast milk showed the highest levels of IgA, whereas serum contained higher IgG levels. A moderate positive correlation was observed between serum and milk IgG. No correlation was found between serum IgG and milk IgA, but both levels were elevated. Conclusions: Breast milk and serum contain relatively high levels of antibodies against the tested respiratory viruses. The elevated levels of serum IgG and milk IgA indicate a coordinated defence between systemic and mucosal immunity in response to infections. The levels and correlation of specific isotypes point to the source of the antibodies: milk IgG probably originates from the blood, whereas milk IgA is produced locally. Full article

Background: The steady increase in allergic diseases among children has coincided with increased global vaccination coverage and the expansion of routine childhood immunization programs. This has contributed to the widespread belief that there is a possible link between immunoprophylaxis and allergic diseases. However, a number of scientific studies have demonstrated the protective effect of early neonatal immunization on the development of nonspecific immunological protection against infections. This is believed to be due to a shift in the immune response from the Th2 type, traditionally predominant in newborns, to the Th1 type, which reduces the risk of developing allergic diseases. Methods: This prospective cohort study analyzed the medical records of 2279 children born between 2018 and 2022 to evaluate the impact of neonatal BCG-M and hepatitis B (HepB) vaccination on the incidence of atopic dermatitis (AD) by 36 months of age. Factors analyzed included family history of allergy, cesarean section, prematurity, delayed initiation of breastfeeding, maternal antibiotic use during pregnancy, and antibiotic use in the child during the first three years of life. Results: The cumulative incidence of AD by 36 months of age was 19.9%. Timely neonatal vaccination coverage was 76.2% for BCG-M and 69.2% for HepB; by 12 months of age, these rates increased to 90.2% and 88.5%, respectively. A full-term birth demonstrated a significant protective effect (OR 0.52; 95% CI 0.30–0.93). A positive family history of allergy was the strongest predictor of AD (OR 21.49; 95% CI 14.4–32.9). Cesarean section was also significantly associated with AD (OR 1.30; 95% CI 1.01–1.65). AD incidence was comparable between vaccinated (20.5%) and non-vaccinated (17.5%) children (chi-squared with Yates’ correction, p = 0.192), indicating no statistically significant overall impact of immunization on AD risk. Conclusions: The development of AD is primarily driven by hereditary predisposition and specific perinatal factors rather than by routine immunization. These findings confirm that neonatal BCG-M and HepB vaccination does not increase the risk of AD, providing a scientific basis to address vaccine hesitancy. Full article

Respiratory Syncytial Virus infection is a significant cause of morbidity and mortality in infants. Maternal vaccination with the bivalent vaccine Abrysvo^® in the third trimester (24–36 weeks) is an effective strategy to prevent severe respiratory illnesses in newborns. However, the introduction of this new technology faces structural obstacles that amplify inequalities. This rapid literature review sought to map and synthesize evidence on inequalities and inequities in adherence and accessibility to maternal vaccination among Black pregnant women. A rapid literature review was conducted using a mixed-methods approach (narrative synthesis and thematic analysis), following guidelines adapted from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Handbook. The research question was structured using the acronym Population/Problem, Exposure, Comparison, and Outcome, focusing on Black pregnant women, maternal vaccination, comparison with other groups, and barriers/determinants. The search was conducted in databases such as PubMed (via Medical Literature Analysis and Retrieval System Online), Scopus and Literatura Latino-Americana e do Caribe em Ciências da Saúde, covering studies published between 2022 and 2025 that presented disaggregated analysis by race. The analysis and interpretation of the findings were guided by Critical Race Theory. The analysis of the twelve included studies (mainly from the United States, the United Kingdom, and Brazil) revealed systematic and robust disparities. Black pregnant women had lower vaccination coverage and were less likely to receive timely recommendations compared to White pregnant women. The barriers identified include: institutional distrust (resulting from structural racism), poor access to prenatal care, inadequate communication, and socioeconomic factors. Inequities are structural and multifactorial phenomena. To ensure that the benefits of the vaccine are distributed equitably, strategies such as anti-racist training for healthcare teams, active vaccination outreach, and continuous monitoring of data disaggregated by race are essential. Full article

Herpes simplex virus type 2 (HSV-2) is the primary pathogen responsible for genital herpes. Predominantly transmitted via sexual contact, HSV-2 not only poses significant physical and psychological burdens on infected individuals but also substantially elevates the risk of HIV acquisition and represents a potentially fatal threat to newborns. Following primary infection, HSV-2 establishes lifelong latent infection within the sacral ganglia. Currently, there are no vaccines or therapeutics capable of eradicating this latent virus reservoir or effectively preventing initial infection. The core impediment to developing such interventions lies in the incomplete elucidation of the protective immune mechanisms against HSV-2 and its precise molecular pathogenesis. The host immune response against HSV-2 hinges critically on the coordinated interplay between innate and adaptive immunity. The innate immune system, serving as the first line of defense, acts to curtail early viral replication and initiate adaptive responses. This is achieved through mechanisms, including the genital mucosal barrier, activation of Toll-like receptors (TLRs), the cGAS-STING signaling pathway, interferon (IFN)-mediated antiviral effector functions, and activation of innate immune cells such as natural killer (NK) cells and dendritic cells (DCs). Crucially, however, HSV-2 counteracts these host defenses by expressing immune modulatory proteins (e.g., ICP0, ICP27, ICP35) that target key host antiviral signaling pathways, thereby affecting immune evasion. Within the adaptive immune response, neutralizing antibodies generated by the humoral immunity can provide localized protection at mucosal sites, but their protective efficacy is limited due to sophisticated viral immune evasion mechanisms. Cellular immunity, particularly mediated by CD4+ T cells, constitutes the core mechanism for viral clearance and suppression of recurrent outbreaks. Notably, tissue-resident memory T cells (TRMs) play a pivotal role in controlling the reactivation of latent HSV-2 within the ganglia. This review integrates current research advances to delineate the innate and adaptive immune mechanisms engaged during HSV-2 infection from the perspective of the dynamic host–virus interplay, with an ultimate aim to provide a theoretical foundation informing the rational development of preventive vaccines and therapeutic agents against HSV-2. Full article

Background/Objectives: Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infections in infants/newborns, sometimes requiring hospitalisation. Two immunisation options are approved in Europe: maternal vaccination and infant immunisation. Success of the immunisation programme depends on uptake—however, understanding of women’s immunisation preferences remains limited. This study evaluated women’s knowledge of RSV, RSV immunisation intentions, and factors influencing immunisation decisions in Finland, France, Germany, Italy, Spain, and the UK. Methods: A cross-sectional survey was conducted between November and December 2024 with 740 women across the selected countries. Participants included women who were pregnant, trying to conceive, or previously pregnant within the year prior to survey. Participants were asked about their knowledge, intentions, and preferences regarding RSV immunisation. Results: Familiarity with RSV was lower than that for COVID-19 and influenza (45% vs. 86% and 85%). Among those pregnant or trying to conceive, 68% reported they were likely to initiate an RSV immunisation discussion with a healthcare provider and 21% reported they were unlikely to do so. The majority (76%) also reported they were likely to accept RSV vaccination if recommended by a healthcare provider. Overall, 52% preferred maternal vaccination over infant immunisation. Among the 82% of women who would consider RSV immunisation and had a preference for immunisation method, 68% favoured maternal vaccination. Conclusions: RSV immunisation acceptance among European women is high and a majority prefer maternal vaccination over infant immunisation. This indicates potential for RSV immunisation to achieve high uptake when women have access to immunisation methods aligned with their preferences. Full article

Background: Readmission of newborns within the first 28 days after initial discharge represents a significant healthcare concern, causing distress to families and financial burden on healthcare systems. Understanding readmission patterns and risk factors is essential for implementing preventive strategies. Objective: This retrospective observational study aimed to evaluate the prevalence and characteristics of neonatal readmissions to a pediatric center in Ploiești, Romania, during a 12-month period (1 January 2024–31 December 2024). Methods: We reviewed medical records of all newborns aged 0–28 days admitted to the pediatric hospital after initial discharge from maternity wards. Clinical characteristics, diagnoses, paraclinical findings, and demographic data were analyzed. Results: A total of 131 newborns were readmitted, representing a 1.9% readmission rate, and only the first readmission for each patient was included in the analysis. The majority (60.9%) presented with preventable infectious pathology, including bronchiolitis (18.3%), rhinoconjunctivitis (16%), pyoderma (11.4%), infectious gastroenteritis (8.4%), and COVID-19 infection (6.8%). Males comprised 61.3% of cases, and 74.8% were born via cesarean section. Exclusive breastfeeding rate was 45.8%. Concerningly, two cases (1.5%) presented with measles, reflecting declining vaccination coverage in Romania (the lowest in the European Union at 62%). Conclusions: The predominance of preventable infectious conditions among neonatal readmissions highlights critical gaps in post-discharge care and infection prevention education. The presence of vaccine-preventable diseases underscores the urgent need to address declining immunization rates in Romania. Enhanced parental education on hygiene practices, infection prevention, and improved post-discharge follow-up systems are essential to reduce neonatal morbidity and readmission rates. Full article

The transplacental transfer of maternal immunoglobulin G from the mother to the foetus is central for providing immunity in early life, resulting in full-term newborns having IgG repertoires and levels similar to those of their mothers. The neonatal Fc receptor is recognised as the primary transporter of IgGs across the placental epithelium. Understanding the mechanisms of transplacental antibody transfer and factors that affect them is essential in optimising maternal vaccination strategies, ultimately protecting infants from various environmental pathogens. This review first outlines the biological mechanisms governing transplacental IgG transfer, followed by a discussion of how this process may be disrupted by physiological and pathological conditions during pregnancy, including preterm birth, hypergammaglobulinemia, maternal pathogenic IgG, maternal infections, hyperglycaemia, and exposure to biological therapies. We also summarise currently available models used to study transplacental IgG transfer, highlighting existing knowledge gaps and future directions for research in this field. Full article

Porcine epidemic diarrhea virus (PEDV) is a highly infectious virus that leads to severe diarrhea and high death rates in neonatal piglets. Because PEDV primarily infects the intestinal mucosa, the induction of effective mucosal immunity through oral vaccination represents a promising strategy for disease prevention. In this study, a recombinant Lactobacillus paracasei (L. paracasei) strain expressing a multicomponent fusion antigen composed of the PEDV S1 protein, M cell- and dendritic cell-targeting peptides, and the mucosal adjuvant LTB was constructed as a candidate oral vaccine. Pregnant mice orally immunized with the recombinant strain exhibited significantly increased levels of PEDV-specific serum IgG as well as secretory IgA (SIgA) in intestinal mucus and feces, both of which showed in vitro neutralizing activity. In addition, oral immunization markedly enhanced cellular immune responses, as indicated by elevated serum levels of IFN-γ, IL-2, IL-4, and IL-10. Notably, newborn mice delivered by immunized dams displayed significantly higher levels of PEDV-specific SIgA, demonstrating effective maternal antibody transfer. These results indicate that the recombinant L. paracasei strain can robustly induce humoral, cellular, and mucosal immune responses and confer maternal immune protection. This study emphasizes the possibility of oral vaccinations based on L. paracasei as a viable approach to the prevention and management of epidemic diarrhea in piglets. Full article