Goal: The present study intended to evaluate whether the profile of soluble immune mediators observed in cord blood samples resembles the pattern identified for mother serum samples.Methods: For this purpose, parallel analysis of chemokines, cytokines, and growth factors was carried out in mother–newborn paired samples from acute and convalescent COVID-19 subgroups (Early, Intermediate, and Late) as well as healthy controls (HC).Results: Data demonstrated that increased levels of CCL11, IFN-γ, IL1-Ra, and G-CSF were observed in cord blood samples from most COVID-19 subgroups, with fold change magnitude from 1.6× to 8.2× as compared with HC. Comparative analysis of mother–newborn pairs demonstrated that several immune mediators (CCL11, CCL4, IFN-γ, PDFG, and G-CSF) exhibited high increment magnitude in cord blood as compared with mother serum, reaching values up to 15.7×, mainly at convalescent COVID-19 infection. The signatures of soluble immune mediators revealed distinct waveforms for cord blood and mother serum, with a waning of immune mediators in the latter, contrasting with the increasing set of molecules in the former from acute toward convalescent COVID-19. Integrative network analysis of immune mediators in mother–newborn pairs showed an increase of neighborhood connectivity both in microenvironments and in their interplay from acute toward late convalescent COVID-19. Our results support the hypothesis of the interplay between mother serum and cord blood microenvironment that may impact the fetus development.Conclusion: Together, this evidence regarding the maternal–fetal crosstalk can ultimately subsidize the improvement of clinical practice and public health policies for management of prenatal exposure to SARS-CoV-2 infection.

Introduction: Little is known about the effects of intrauterine exposure to SARS-CoV-2, especially on growth and neurodevelopment in children. Objective: We wished to verify the effect of intrauterine exposure to SARS-CoV-2 on neurological development in children. Methods: Infants born to mothers presenting with SARS-CoV-2 infection during pregnancy were enrolled in a prospective descriptive–analytical study involving outpatient appointments performed 6 and 12 months after birth. Their neurological development was assessed using the Bayley-III Scale, using a score of >85 as the cutoff threshold for identifying developmental delay. Differences between groups were assessed through an ANOVA, using Bonferroni correction for multiple comparisons. Regression models were employed to examine the associations between the Bayley-III scores and maternal features. Results: Two hundred and sixty-nine infants were evaluated, most of whom were born full-term and with birth weights appropriate for gestational age at delivery. Developmental delays were observed in 26% of the infants in at least one of the Bayley-III domains. The language domain was particularly affected, with impairments observed in children exposed to SARS-CoV-2 closer to the time of delivery. These findings were statistically significant (p < 0.05). Conclusions: Infants born to mothers presenting with SARS-CoV-2 infection during pregnancy presented developmental delays at 6 and 12 months, particularly in the language domain. These findings reinforce the relevance of long-term clinical follow-ups of newborns exposed to SARS-CoV-2 infection during pregnancy.

Background: Acute lymphoblastic leukemia is the most prevalent childhood cancer and the leading cause of cancer mortality before the age of 20. Although therapeutic advances have significantly improved survival, children and adolescents treated for acute lymphoblastic leukemia remain vulnerable to infections, largely preventable by vaccination, due to humoral and cellular immune dysfunction induced by disease and treatment. Materials and Methods: This systematic review, based on electronic databases, aims to evaluate antibody levels associated with potential protective immunity against vaccine antigens for diphtheria, pertussis, tetanus, poliomyelitis, Haemophilus influenzae type b, measles, mumps, rubella, influenza, varicella-zoster virus, yellow fever, pneumococcal, and meningococcal diseases in children and adolescents treated for acute lymphoblastic leukemia after completion of chemotherapy. Results: A total of twenty-four studies published between 1981 and 2023 were included, comprising 1110 children and adolescents. Protective antibody levels ranged from 11% to 97% for diphtheria, 0% to 90% for pertussis, 20% to 100% for tetanus, and 11% to 95% for poliomyelitis. Haemophilus influenzae type b, protection ranged from 16.7% to 100%. Viral vaccines also showed heterogeneous responses, with protection rates of 25–79% for mumps, 16–86% for measles, 35–98% for rubella, and 23–75% for varicella-zoster virus. Antibody responses to pneumococcal and meningococcal vaccines were consistently low, with protection rates of 5–38% for pneumococcal studies and 12% in a single meningococcal study. Conclusions: This review found a consistent and clinically relevant loss of vaccine-induced immunity in children and adolescents treated for acute lymphoblastic leukemia. The recommendation of vaccine booster doses for this vulnerable population, irrespective of serological status, may represent a more practical approach to ensuring adequate post-chemotherapy treatment protection.