Maternal COVID-19 Vaccination and Its Potential Impact on Fetal and Neonatal Development

Vaccines have been developed at “warp speed” to combat the COVID-19 pandemic caused by the SARS-CoV-2 coronavirus. Although they are considered the best approach for preventing mortality, when assessing the safety of these vaccines, pregnant women have not been included in clinical trials. Thus, vaccine safety for this demographic, as well as for the developing fetus and neonate, remains to be determined. A global effort has been underway to encourage pregnant women to get vaccinated despite the uncertain risk posed to them and their offspring. Given this, post-hoc data collection, potentially for years, will be required to determine the outcomes of COVID-19 and vaccination on the next generation. Most COVID-19 vaccine reactions include injection site erythema, pain, swelling, fatigue, headache, fever and lymphadenopathy, which may be sufficient to affect fetal/neonatal development. In this review, we have explored components of the first-generation viral vector and mRNA COVID-19 vaccines that are believed to contribute to adverse reactions and which may negatively impact fetal and neonatal development. We have followed this with a discussion of the potential for using an ovine model to explore the long-term outcomes of COVID-19 vaccination during the prenatal and neonatal periods.

Olfactory-driven beta band entrainment of limbic circuitry during neonatal development

ABSTRACTCognitive processing relies on the functional refinement of the limbic circuitry during the first two weeks of life. During this developmental period, when most sensory systems are still immature, the sense of olfaction acts as “door to the world”, providing the main source of environmental inputs. However, it is unknown whether early olfactory processing shapes the development of the limbic circuitry. Here, we address this question by combining simultaneous in vivo recordings from the olfactory bulb (OB), lateral entorhinal cortex (LEC), hippocampus (HP), and prefrontal cortex (PFC) with opto- and chemogenetic manipulations of mitral/tufted cells (M/TCs) in the OB of non-anesthetized neonatal mice. We show that the neonatal OB synchronizes the limbic circuity in beta frequency range. Moreover, it drives neuronal and network activity in LEC, as well as subsequently, HP and PFC via long-range projections from mitral cells (MCs) to HP-projecting LEC neurons. Thus, OB activity controls the communications within limbic circuits during neonatal development.

Correlation of Environment, Nutrition, Genetics, Epigenetics, Microbiota with Neonatal Fetus Development

Introduction: From the moment of conception the human being is predisposed to undergo changes in fetal and neonatal development due to various external factors that occur throughout life and can in the long term influence the phenotypic expression of the new being. Objective: The objective of this work is to determine the relationship between the environment, nutrition, genetics, epigenetics and microbiota with neonatal fetus development and how they influence the phenotypic expression of the new being. Methods: A non-systematic search was performed in electronic databases such as COCHRANE, PUBMED, MEDLINE, etc. The bibliographic research was carried out in the period between October 2019 and January 2020. The studies carried out from 2007 to 2019, in the languages of Spanish and English, were included. Results: We found 51 bibliographic sources related to the subject, of which by means of a last simplification, 30 scientific articles were used that provided important information on the subject, and 21 articles were excluded. Conclusion: Research on methods to detect these interactions and to understand the mechanisms of these interactions is just beginning. However, there is evidence that they play an important role in human development. Keywords: neonatal development, epigenetics, microbiota, fetal development, nutrition. RESUMEN Introducción: Desde el momento de la concepción el ser humano está predispuesto a sufrir cambios en el desarrollo fetal y neonatal debido a diversos factores externos que se presentan a lo largo de la vida y pueden a largo plazo influir en la expresión fenotípica del nuevo ser. Objetivo: El objetivo del presente trabajo es determinar la relación que existe entre el medio ambiente, nutrición, genética, epigenética y microbiota con el desarrollo feto neonatal y como los mismos influyen en la expresión fenotípica del nuevo ser. Métodos: Se realizó una búsqueda no sistemática en bases de datos electrónicas como COCHRANE, PUBMED, MEDLINE, etc. La investigación bibliográfica se realizó en el periodo comprendido entre octubre 2019 y enero 2020. Se incluyeron estudios realizados desde el año 2007 hasta el año 2019, en los idiomas de español e inglés. Resultados: Se encontraron 51 fuentes bibliográficas referentes al tema, de los cuales mediante una última simplificación se utilizaron 30 artículos científicos que aportaron información importante del tema y se excluyeron 21 artículos. Conclusiones: La investigación sobre métodos para detectar estas interacciones y para comprender los mecanismos de estas interacciones apenas está comenzando. Sin embargo, hay evidencia de que estas juegan un papel importante en el desarrollo humano. Palabras clave: desarrollo neonatal, epigenética, microbiota, desarrollo fetal, nutrición.

Eggshell and Feed Microbiota Do Not Represent Major Sources of Gut Anaerobes for Chickens in Commercial Production

In this study, we addressed the origin of chicken gut microbiota in commercial production by a comparison of eggshell and feed microbiota with caecal microbiota of 7-day-old chickens, using microbiota analysis by 16S rRNA sequencing. In addition, we tested at which timepoint during prenatal or neonatal development it is possible to successfully administer probiotics. We found that eggshell microbiota was a combination of environmental and adult hen gut microbiota but was completely different from caecal microbiota of 7-day-old chicks. Similarly, we observed that the composition of feed microbiota was different from caecal microbiota. Neither eggshell nor feed acted as an important source of gut microbiota for the chickens in commercial production. Following the experimental administration of potential probiotics, we found that chickens can be colonised only when already hatched and active. Spraying of eggs with gut anaerobes during egg incubation or hatching itself did not result in effective chicken colonisation. Such conclusions should be considered when selecting and administering probiotics to chickens in hatcheries. Eggshells, feed or drinking water do not act as major sources of gut microbiota. Newly hatched chickens must be colonised from additional sources, such as air dust with spores of Clostridiales. The natural colonisation starts only when chickens are already hatched, as spraying of eggs or even chickens at the very beginning of the hatching process did not result in efficient colonisation.

PPARγ is essential for the development of bone marrow erythroblastic island macrophages and splenic red pulp macrophages

Tissue-resident macrophages play a crucial role in maintaining homeostasis. Macrophage progenitors migrate to tissues perinatally, where environmental cues shape their identity and unique functions. Here, we show that the absence of PPARγ affects neonatal development and VCAM-1 expression of splenic iron-recycling red pulp macrophages (RPMs) and bone marrow erythroblastic island macrophages (EIMs). Transcriptome analysis of the few remaining Pparg-deficient RPM-like and EIM-like cells suggests that PPARγ is required for RPM and EIM identity, cell cycling, migration, and localization, but not function in mature RPMs. Notably, Spi-C, another transcription factor implicated in RPM development, was not essential for neonatal expansion of RPMs, even though the transcriptome of Spic-deficient RPMs was strongly affected and indicated a loss of identity. Similarities shared by Pparg- and Spic-deficient RPM-like cells allowed us to identify pathways that rely on both factors. PPARγ and Spi-C collaborate in inducing transcriptional changes, including VCAM-1 and integrin αD expression, which could be required for progenitor retention in the tissue, allowing access to niche-related signals that finalize differentiation.