Anti-Infective, Anti-Inflammatory, and Immunomodulatory Properties of Breast Milk Factors for the Protection of Infants in the Pandemic From COVID-19

Investigation of Anti-SARS-CoV-2-specific IgG Levels in Breast Milk after Vaccination or COVID-19 Infection

OBJECTIVE

 Newborns are vulnerable to all types of infections due to their developing immune system. To compensate for their immune immaturity, newborns rely on the passive transfer of antibodies through the placenta and own mother's breast milk (BM). In the present study, we investigated whether vaccination against SARS-CoV-2 leads to the presence of antibodies in BM. Furthermore, we compared the levels of SARS-CoV-2-specific anti-spike (anti-S) IgG antibodies in the BM of mothers who were vaccinated against Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or had coronavirus disease 2019 (COVID-19) infection naturally or were vaccinated after natural infection.

STUDY DESIGN

 This was a prospective cohort study conducted in the Ondokuz Mayis University Faculty of Medicine. Forty-six mothers who had at least two doses of the BNT162b2 messenger RNA-based vaccine and/or had a history of symptomatic COVID-19 infection were included in the study. BM samples were analyzed by the Abbott Architect SARS-CoV-2 IgG II Quant kit following the manufacturer's instructions.

RESULTS

 Forty-six mothers with an average age of 29.7 ± 5.7 years participated the study: 18 (39.1%) had COVID-19 infection + BTN162b2 vaccine, 17 (37.0%) had BTN162b2 vaccine, and 11 (23.9%) had natural infection. The highest SARS-CoV-2-specific anti-S IgG antibody titers in BM were found in mothers who were vaccinated following the infection (anti-SARS-CoV-2 IgG: 32.48 ± 57.1 arbitrary units AU/mL). However, no significant difference in anti-SARS-CoV-2 antibody levels was observed between the three groups (p = 0.641). No antibody was detected in 15.2% of BM samples.

CONCLUSION

 Both vaccination and natural COVID-19 infection during pregnancy leads to the passive transfer of specific anti-SARS-CoV-2 IgG antibodies to BM. These results are important to overcome vaccine hesitancy and increase vaccination levels in expectant mothers.

KEY POINTS

· We investigated the levels of SARS-CoV-2 antibodies in BM after natural infection and vaccination.. · Anti-SARS-CoV-2 IgG antibodies were detected in 39 (84.8%) BM samples.. · The highest titers in BM were found in mothers who were vaccinated following natural infection..

Multicenter Study of Rotavirus Infection, Diversity of Circulating Genotypes and Clinical Outcomes in Children ≤5 Years Old in Iran

BACKGROUND

To determine the epidemiology of rotavirus group A (RVA) infection in symptomatic children, and analyze genotype diversity in association with clinical characteristics, geographical and seasonal changes.

METHODS

The stool samples of symptomatic children 5≥ years old were collected from 5 different hospitals during December 2020 and March 2022. Rotavirus stool antigen test was done and G and P genotypes of the positive samples were determined. Associations of the infection and genotype diversity with demographical and clinical data were assessed by statistical methods.

RESULTS

RVA infection was detected in 32.1% (300/934) of the patients (Ranges between 28.4% and 47.4%). An inverse association with age was detected, where the highest frequency was measured in children ≤12 months of age (175/482, 36.3%). The infection was more frequent during winter (124/284, 43.7%) and spring (64/187, 34.2%). Children who were exclusively fed with breast milk showed a lower rate of infection (72/251, 28.6%). Among the 46 characterized genotypes (17 single- and 29 mixed-genotype infections), G1P[8] and G9P[4] were more frequently detected in children <36 (67/234, 28.63%) and 36-60 (7/24, 29.16%) months of age children, respectively. A seasonal diversity in the circulating genotypes was detected in different cities. Children with G1P[8], G1P[6], and mixed-genotype infection experienced a shorter duration of hospitalization, and a higher frequency of nausea and severe diarrhea, respectively.

CONCLUSIONS

In this study high frequency of RVA infection was detected in symptomatic children in Iran. Moreover, genotype diversity according to geographic area, seasons, age groups, and clinical features of disease was detected.

Breastfeeding in infants who aspirate may increase risk of pulmonary inflammation

OBJECTIVE

To evaluate management strategies and pulmonary outcomes for breastfed infants with oropharyngeal dysphagia.

STUDY DESIGN

We performed a retrospective cohort study of breastfed infants diagnosed with oropharyngeal dysphagia with documented aspiration or laryngeal penetration on videofluoroscopic swallow study (VFSS). Medical records were reviewed for VFSS results and speech-language pathologist recommendations following VFSS, results of chest x-ray, results of bronchoalveolar lavage (BAL) within 1 year of VFSS, and aspiration-related hospitalizations occurring before or within 1 year of VFSS. Subjects were categorized as cleared or not cleared to breastfeed based on the VFSS. Proportions were compared with Chi-square and Fisher's exact tests and means with Student's t-tests.

RESULTS

Seventy-six infants (4.7 ± 0.4 months old) were included; 50% (38) had aspiration and 50% (38) had laryngeal penetration. After VFSS, 70% (53) were cleared to breastfeed while 30% (23) were not cleared to breastfeed. Patients with aspiration were less likely to be cleared to breastfeed (p = .006); however, 55% (21/38) of those with aspiration were still cleared to breastfeed. Infants cleared to breastfeed had significantly more pulmonary hospitalizations (p = .04) and were also at increased risk of elevated neutrophil count (p = .02) and culture growth on BAL (p = .01). Significantly increased abnormal neutrophil count was also found in those cleared to breastfeed with laryngeal penetration (p = .01).

CONCLUSIONS

Infants with oropharyngeal dysphagia counseled to continue breastfeeding had increased risk of BAL inflammation and more pulmonary hospitalizations compared to those that were told to stop breastfeeding.

Protective Characteristics of Human Breast Milk on Early Childhood Otitis Media: A Narrative Review

Introduction: Human breast milk (HBM) contains a complex and dynamically changing variety of factors that contribute to the infant's developing immune system's ability to fight upper respiratory tract infections, including otitis media (OM). We sought to summarize the current evidence on the protective characteristics of HBM, through direct or donated feeding, toward early childhood OM. Methods: For this narrative review, we performed a literature search on OM in the context of HBM feeding in the PubMed, Embase, and Google Scholar databases, between January 1, 2008, and July 1, 2023. Results: Immunoglobulin A (IgA) provides a short-term immunity of 2-3 days against otopathogens causing OM. IgA-mediated immunity is effective against OM up to 7 months of age if breastfeeding continues. The role of transferred IgM and IgG in HBM is unclear. Although there is a potential protective value of microRNA, hormones, oligosaccharides, stem cells, and interleukins present in HBM, their role is unclear. Any duration of breastfeeding is superior to no breastfeeding in OM risk reduction, with a big variability among studies (odds ratio 0.23-0.81, depending on the duration). Duration of breastfeeding ≥6 months was found to be the most effective in OM risk reduction, but there was no evidence of continued benefits after 2 years of age. Expressed breastfeeding was not shown to be more beneficial. The protective values of donor HBM against OM are still undetermined. Conclusion: HBM has numerous components that contribute to protection against early childhood OM.

Insight into differences in whey proteome from human and eight dairy animal species for formula humanization

Human breastmilk fulfills the nutritional needs of infants and therefore is the best template for formula. In this study, whey proteins were investigated among human and eight dairy animal species using label-free proteomics approach. Totally, 965 proteins from milk whey were identified and large variations were observed between human and animals. Several proteins, including β-galactosidase, fatty acid synthase, osteopontin, lactoferrin, mannose receptor, and complement C4-A, which are associated with digestion and immune response, exhibited significantly higher levels in human milk whey. Conversely, specific animal milk whey demonstrated elevated abundance of lipocalin 2, lysozyme, and glycosylation-dependent cell adhesion molecule 1. These differential proteins are enriched in complement and coagulation cascades, lysosome, and phagosome pathways. The findings shed light on the variations in the whey proteome composition between human and animal milk, which can contribute to optimizing formula humanization.

Breastfeeding Behavior Within the Covid-19 Related Obstetric and Neonatal Outcome Study (CRONOS)

BACKGROUND

The SARS-CoV-2 pandemic and its influence on peripartum processes worldwide led to issues in breastfeeding support.

RESEARCH AIM

The aim of this study was to describe breastfeeding behavior and peripartum in-hospital management during the pandemic in Germany and Austria.

METHODS

This study was a descriptive study using a combination of secondary longitudinal data and a cross-sectional online survey. Registry data from the prospective multicenter COVID-19 Related Obstetric and Neonatal Outcome Study (CRONOS) cohort study (longitudinal, medical records of 1,815 parent-neonate pairs with confirmed SARS-CoV-2 infection during pregnancy) and a cross-sectional online survey of CRONOS hospitals' physicians (N = 67) were used for a descriptive comparison of feeding outcomes and postpartum management.

RESULTS

In 93.7% (n = 1700) of the cases in which information on the neonate's diet was provided, feeding was with the mother's own milk. Among neonates not receiving their mother's own milk, 24.3% (n = 26) reported SARS-CoV-2 infection as the reason. Peripartum maternal SARS-CoV-2 infection, severe maternal COVID-19 including the need for intensive care unit (ICU) treatment or invasive ventilation, preterm birth, mandatory delivery due to COVID-19, and neonatal ICU admission were associated with lower rates of breastfeeding. Rooming-in positively influenced breastfeeding without affecting neonatal SARS-CoV-2 frequency (4.2% vs. 5.6%). CRONOS hospitals reported that feeding an infant their mother's own milk continued to be supported during the pandemic. In cases of severe COVID-19, four of five hospitals encouraged breastfeeding.

CONCLUSION

Maintaining rooming-in and breastfeeding support services in the CRONOS hospitals during the pandemic resulted in high breastfeeding rates.

Expressed breast milk and maternal expression of breast milk for the prevention and treatment of neonatal hypoglycemia: a systematic review and meta-analysis

BACKGROUND

Worldwide, many guidelines recommend the use of expressed breast milk (EBM) and maternal expression of breast milk for the prevention and treatment of neonatal hypoglycemia. However, the impact of both practices on neonatal hypoglycemia is unclear. This study aims to determine the effectiveness of EBM and maternal expression of breast milk in preventing and treating neonatal hypoglycemia.

METHODS

We registered our review in PROSPERO (CRD42022328072). We systematically reviewed five databases and four clinical trial registries to identify randomized controlled trials (RCT), non-randomized studies of intervention (NRSI), and cohort studies that compared infants who received EBM to infants who did not, and similar study designs that compared infants whose mothers expressed breast milk to infants whose mothers did not. Two independent reviewers carried out screening, data extraction, and quality assessment. The quality of included RCT, NRSI, and cohort studies were respectively assessed with the Cochrane Risk of Bias 2, Risk Of Bias In Non-randomised Studies-of Interventions, and the Newcastle-Ottawa Scale tools. Results from studies on EBM were synthesized separately from those on maternal expression of breast milk. Meta-analysis was undertaken using Revman 5.4. and fixed-effect models.

RESULTS

None of the ten included studies was specifically designed to determine the effect of EBM or maternal expression of breast milk on neonatal hypoglycemia. The effect of EBM on neonatal hypoglycemia was not estimable. There was no difference in the risk of hypoglycaemia among neonates whose mothers expressed breast milk compared to those whose mothers did not [RR (95%CI); one RCT: 0.92 (0.77, 1.10), high-certainty evidence; one cohort: 1.10 (0.74, 1.39), poor quality study].

CONCLUSIONS

There is insufficient evidence to determine the effectiveness of EBM for preventing or treating neonatal hypoglycemia. Limited data suggests maternal breast milk expression may not alter the risk of neonatal hypoglycemia. High-quality randomized controlled trials are needed to determine the effectiveness of EBM and maternal expression of breast milk for the prevention and treatment of neonatal hypoglycemia.

The contributions of parental lactation on offspring development: It's not udder nonsense!

The Developmental Origins of Health and Disease (DOHaD) hypothesis describes how maternal stress exposures experienced during critical periods of perinatal life are linked to altered developmental trajectories in offspring. Perinatal stress also induces changes in lactogenesis, milk volume, maternal care, and the nutritive and non-nutritive components of milk, affecting short and long-term developmental outcomes in offspring. For instance, selective early life stressors shape the contents of milk, including macro/micronutrients, immune components, microbiota, enzymes, hormones, milk-derived extracellular vesicles, and milk microRNAs. In this review, we highlight the contributions of parental lactation to offspring development by examining changes in the composition of breast milk in response to three well-characterized maternal stressors: nutritive stress, immune stress, and psychological stress. We discuss recent findings in human, animal, and in vitro models, their clinical relevance, study limitations, and potential therapeutic significance to improving human health and infant survival. We also discuss the benefits of enrichment methods and support tools that can be used to improve milk quality and volume as well as related developmental outcomes in offspring. Lastly, we use evidence-based primary literature to convey that even though select maternal stressors may modulate lactation biology (by influencing milk composition) depending on the severity and length of exposure, exclusive and/or prolonged milk feeding may attenuate the negative in utero effects of early life stressors and promote healthy developmental trajectories. Overall, scientific evidence supports lactation to be protective against nutritive and immune stressors, but the benefits of lactation in response to psychological stressors need further investigation.

Pro-and Antioxidant Status in Newborn with COVID-19

There is practically no information on the state of oxidative stress reactions in newborns with coronavirus infections. At the same time, such studies are extremely important and can contribute to better understanding of the process of reactivity in patients of different ages. The content of pro- and antioxidant status indicators was assessed in 44 newborns with confirmed COVID-19. It was found that the content of compounds with unsaturated double bonds, primary, secondary, and final LPO products were elevated in newborns with COVID-19. These changes were accompanied by higher SOD activity and retinol level and reduced activity of glutathione peroxidase. Contrary to popular opinion, newborns can be a COVID-19-susceptible age group and require more close monitoring of metabolic reactions during the period of neonatal adaptation that is an aggravating background during infection.

Clinical characteristics of COVID-19 in hospitalized young infants and risk factors for disease severity

BACKGROUND

This study aimed to describe the clinical characteristics and severity of young infants hospitalized with COVID-19 and study the relationship between breastfeeding and maternal COVID-19 vaccination on the severity of COVID-19.

METHODS

A retrospective, observational study was performed among infants aged 6 months and below hospitalized for COVID-19 in a tertiary state hospital in Malaysia between February 1 and April 30, 2022. The primary outcome was "serious disease," defined as pneumonia requiring respiratory support or dehydration with warning signs. Multivariate logistic regression was used to determine independent predictors for serious disease.

RESULTS

A total of 102 infants were included in the study; 53.9% were males with a median age of 11 weeks (interquartile range: 5-20 weeks). Sixteen patients (15.7%) had pre-existing comorbidities, including preterm birth. Fever was the most common presenting symptom (82.4%), followed by cough (53.9%), and rhinorrhea (31.4%). Forty-one infants (40.2%) presented with serious disease, warranting either respiratory support or intravenous fluid therapy for dehydration. Recent maternal COVID-19 vaccination was associated with a reduced risk of serious disease on univariate analysis but was not significant after multivariate adjustment (adjusted odds ratio [aOR] 0.39; 95% CI: 0.14-1.11; p = 0.08). Exclusive breastfeeding was protective against serious COVID-19 in young infants, independent of other confounding factors (aOR 0.21, 95% CI: 0.06-0.71; p = 0.01).

CONCLUSION

COVID-19 is a serious disease with non-specific clinical manifestations in young infants. Exclusive breastfeeding could play an important protective role.

Postnatal growth of small for gestational age late preterm infants: determinants of catch-up growth

BACKGROUND

Failure to recover growth is a risk reported in late preterm population. This study aimed to evaluate the auxological outcome of late preterm infants and identify factors associated with failure to recover growth.

METHODS

We enrolled late preterm infants with birth weight ≤10th percentile, followed up at High-Risk Infant Follow-up Service. We collected data at birth and at follow-up visits. A logistic regression analysis was performed to assess variables independently associated with growth failure.

RESULTS

The population consisted of 175 preterms. The percentage of children showing no weight recovery was 34% at 36 months. At logistic regression analysis, infants who had not regained weight at 12 months had a higher risk of not regaining weight even at 36 months. The same risk factor was highlighted for length catch-up growth. Moreover, infants fed any human milk at discharge were protected from not achieving both weight and length catch-up growth at 36 months.

CONCLUSION

These results indicate that children born late preterm and small for gestational age could fail to recover weight and stature growth in the first 36 months. The protective effect of human milk on failure to thrive highlights the importance of promoting breastfeeding in this population.

IMPACT

A significant number of SGA late preterms show a failure to recover weight and statural growth. Having experienced intrauterine growth restriction is associated with a greater chance of achieving statural catch-up growth. Being born singleton represents a risk factor for slower weight and height growth velocity. Breastmilk has a protective effect on failure to recover adequate weight and length in preterm SGA infants. This finding highlights the importance of promoting breastfeeding in this population.

[Association between postpartum depression and concentrations of transforming growth factor-β in human colostrum: a nested cohort study]

OBJECTIVE

To explore the association between postpartum depression (PPD) and transforming growth factor-β (TGF-β) concentrations in human colostrum.

METHODS

Participants were recruited from a maternal and infant cohort established in a tertiary general hospital in Guangdong Province between December, 2020 and September, 2021. In the afternoon of the second postpartum day, the women were evaluated with Edinburgh Postnatal Depression Scale (EPDS) for screening PPD (defined as a score of 10 or higher). The women with PPD were matched at a 1:1 ratio with women without PPD with maternal age difference within 5 years and the same mode of delivery. Colostrum samples were collected in morning on the third postpartum day for measurement of TGF-β concentrations using enzyme-linked immunosorbent assay (ELISA), and the association between EPDS scores and TGF-β concentrations was analyzed in the two groups.

RESULTS

A total of 90 women were included in the final analysis. The mean concentrations of TGF-β1, TGF-β2 and TGF-β3 in the colostrum were 684.03 (321.22-859.25) pg/mL, 5116.50±1747.04 pg/mL and 147.84±48.68 pg/mL in women with PPD, respectively, as compared with 745.67 (596.00-964.22) pg/mL, 4912.40±1516.80 pg/mL, and 168.21±48.15 pg/mL in women without PPD, respectively. Compared with women without PPD, the women with PPD had significantly lower concentrations of TGF-β1 (P=0.026) and TGF-β3 (P=0.049) in the colostrum. Spearman correlation analysis revealed that the EPDS scores were negatively associated with the concentrations of TGF-β1 (r=-0.23, P=0.03) and TGF-β3 (r=-0.25, P=0.02) in the colostrum.

CONCLUSION

PPD is associated with decreased concentrations of TGF-β1 and TGF-β3 in human colostrum, suggesting the need of early PPD screening and interventions during pregnancy and the perinatal period to minimize the impact of PPD on human milk compositions.

Human Breast Milk: The Key Role in the Maturation of Immune, Gastrointestinal and Central Nervous Systems: A Narrative Review

Premature birth is a major cause of mortality and morbidity in the pediatric population. Because their immune, gastrointestinal and nervous systems are not fully developed, preterm infants (<37 weeks of gestation) and especially very preterm infants (VPIs, <32 weeks of gestation) are more prone to infectious diseases, tissue damage and future neurodevelopmental impairment. The aim of this narrative review is to report the immaturity of VPI systems and examine the role of Human Breast Milk (HBM) in their development and protection against infectious diseases, inflammation and tissue damage. For this purpose, we searched and synthesized the data from the existing literature published in the English language. Studies revealed the significance of HBM and indicate HBM as the best dietary choice for VPIs.

Human Milk Oligosaccharides Impact Cellular and Inflammatory Gene Expression and Immune Response

Human milk harbors complex carbohydrates, including human milk oligosaccharides (HMOs), the third most abundant component after lactose and lipids. HMOs have been shown to impact intestinal microbiota, modulate the intestinal immune response, and prevent pathogenic bacterial binding by serving as decoy receptors. However, the direct effect of HMOs on intestinal function and immunity remains to be elucidated. To address this knowledge gap, 21-day-old germ-free mice (C57BI/6) were orally gavaged with 15 mg/day of pooled HMOs for 7 or 14 days and euthanized at day 28 or 35. A set of mice was maintained until day 50 to determine the persistent effects of HMOs. Control groups were maintained in the isolators for 28, 35, or 50 days of age. At the respective endpoints, intestinal tissues were subjected to histomorphometric and transcriptomic analyses, while the spleen and mesenteric lymph nodes (MLNs) were subjected to flow cytometric analysis. The small intestine (SI) crypt was reduced after HMO treatment relative to control at days 28 and 35, while the SI villus height and large intestine (LI) gland depth were decreased in the HMO-treated mice relative to the control at day 35. We report significant HMO-induced and location-specific gene expression changes in host intestinal tissues. HMO treatment significantly upregulated genes involved in extracellular matrix, protein ubiquitination, nuclear transport, and mononuclear cell differentiation. CD4+ T cells were increased in both MLNs and the spleen, while CD8+ T cells were increased in the spleen at day 50 in the HMO group in comparison to controls. In MLNs, plasma cells were increased in HMO group at days 28 and 35, while in the spleen, only at day 28 relative to controls. Macrophages/monocytes and neutrophils were lower in the spleen of the HMO group at days 28, 35, and 50, while in MLNs, only neutrophils were lower at day 50 in the 14-day HMO group. In addition, diphtheria toxoid and tetanus toxoid antibody-secreting cells were higher in HMO-supplemented group compared to controls. Our data suggest that HMOs have a direct effect on gastrointestinal tract metabolism and the immune system even in the absence of host microbiota.

Overview of Breastfeeding Under COVID-19 Pandemic

During the global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), pregnant and lactating women are at higher risk of infection. The potential of viral intrauterine transmission and vertical transmission by breastfeeding has raised wide concerns. Breastmilk is rich in nutrients that contribute to infant growth and development, and reduce the incidence rate of infant illness and death, as well as inhibit pathogens significantly, and protect infants from infection. Although it is controversial whether mothers infected with COVID-19 should continue to breastfeed, many countries and international organizations have provided recommendations and guidance for breastfeeding. This review presents the risks and benefits of breastfeeding for mothers infected with COVID-19, and the reasons for the absence of SARS-CoV-2 active virus in human milk. In addition, the antiviral mechanisms of nutrients in breastmilk, the levels of SARS-CoV-2 specific antibodies in breastmilk from COVID-19 infected mothers and vaccinated mothers are also summarized and discussed, aiming to provide some support and recommendations for both lactating mothers and infants to better deal with the COVID-19 pandemic.

Molecular mechanisms highlighting the potential role of COVID-19 in the development of neurodegenerative diseases

Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition to the pulmonary manifestations, COVID-19 patients may present a wide range of neurological disorders as extrapulmonary presentations. In this view, several studies have recently documented the worsening of neurological symptoms within COVID-19 morbidity in patients previously diagnosed with neurodegenerative diseases (NDs). Moreover, several cases have also been reported in which the patients presented parkinsonian features after initial COVID-19 symptoms. These data raise a major concern about the possibility of communication between SARS-CoV-2 infection and the initiation and/or worsening of NDs. In this review, we have collected compelling evidence suggesting SARS-CoV-2, as an environmental factor, may be capable of developing NDs. In this respect, the possible links between SARS-CoV-2 infection and molecular pathways related to most NDs and the pathophysiological mechanisms of the NDs such as Alzheimer's disease, vascular dementia, frontotemporal dementia, Parkinson's disease, and amyotrophic lateral sclerosis will be explained.

Vaccine Protection Through Placenta and Breastfeeding: The Unmet Topic in COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) pandemic has turned pregnant women’s healthcare into a worldwide public health challenge. Although initial data did not demonstrate pregnancy as a more susceptible period to severe outcomes of acute severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) infection, there are an increasing number of reports showing that not only pregnant women might be at significantly higher risk than non-pregnant women by COVID-19 but also the fetus. These findings may be related to adaptive changes that occur during pregnancy, such as the reduction in the residual respiratory capacity, the decrease in viral immune responses, and the increased risk for thromboembolic events. Additionally, despite the SARS-CoV-2 vertical transmission evidence being uncommon, maternal illness severity might reflect serious perinatal and neonatal outcomes. Thus, protecting the maternal–fetal dyad against COVID-19 is critical. Even though pregnant women initially were excluded from vaccine trials, several studies have provided safety and efficacy of the overall vaccine COVID-19 platforms. Vaccination during pregnancy becomes a priority and can generate benefits for both the mother and newborn: maternal neutralizing antibodies are transmitted through the placenta and breastfeeding. Moreover, regarding passive immunization, human milk contains other bioactive molecules and cells able to modulate the newborn’s immune response, which can be amplified after the vaccine. Nonetheless, many issues remain to be elucidated, considering the magnitude of the protective immunity transferred, the duration of the induced immunity, and the optimal interval for pregnant immunization. In this review, we assessed these unmet topics supported by literature evidence regarding the vaccine’s immunogenicity, pregnancy immune heterogeneity, and the unique human milk antiviral features.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

Relationship Between Maternal COVID-19 Infection and In-Hospital Exclusive Breastfeeding for Term Newborns

Objective

To evaluate the relationship between maternal COVID-19 infection and the odds of in-hospital exclusive breastfeeding for term newborns.

Design

Retrospective descriptive quantitative.

Setting

A large, urban hospital with more than 6,000 births annually.

Sample

Term newborns born between March 1, 2020, and March 31, 2021 (N = 6,151).

Methods

We retrospectively extracted data from electronic health records to evaluate the relationship of maternal COVID-19 infection with the odds of in-hospital exclusive breastfeeding using univariate analysis and logistic regression models. The covariates included insurance type, race/ethnicity, glucose gel administration, length of stay, newborn gestational age, newborn birth weight, and maternal COVID-19 infection.

Results

Maternal COVID-19 infection was not significantly related to the odds of in-hospital exclusive breastfeeding (p = .138) after adjustment for covariates in the logistic regression model. However, when newborns who received pasteurized donor human milk supplementation were excluded from the logistic regression model, maternal COVID-19 infection significantly decreased the odds of in-hospital exclusive breastfeeding (p = .043).

Conclusion

Maternal COVID-19 infection was not significantly related to the odds of in-hospital exclusive breastfeeding when newborns received donor human milk supplementation. Access to donor human milk for supplementation for term newborns may protect the odds of in-hospital exclusive breastfeeding.

Comparing the human milk antibody response after vaccination with four COVID-19 vaccines: A prospective, longitudinal cohort study in the Netherlands

BACKGROUND

Vaccination of lactating women against COVID-19 may protect not only themselves but also their breastfed infant through human milk. Therefore, it is important to gain insight into the human milk antibody response after immunization with the various vaccines that are currently widely used. The aim of this study is to determine and compare the antibody response in human milk following vaccination with mRNA- and vector-based vaccines up to over two months post-vaccination.

METHODS

This prospective cohort study was conducted in the Netherlands between January 06, 2021 and July 31, 2021. Participants were recruited through social media. Human milk samples were collected longitudinally during a period of 70 days from women receiving one of the four different severe acute respiratory coronavirus 2 (SARS-CoV-2) vaccines: Pfizer-BioNTech (BNT162b2), Moderna (mRNA-1273), Oxford/AstraZeneca (AZD1222) and Johnson&Johnson (Ad26.COV2.S). SARS-CoV-2-specific antibodies were measured using an enzyme-linked immunosorbent assay. The area under the curve (AUC) of the Immunoglobulins A (IgA) and G (IgG) antibody response was determined over 15 and 70 days following the first vaccination and compared between the different vaccines.

FINDINGS

This study enrolled 134 vaccinated lactating women of whom 97 participated the entire study period. In total, 1887 human milk samples were provided. The human milk antibody response differed between SARS-CoV-2 vaccines over the study period. The mean AUC of SARS-CoV-2-specific IgA, but not IgG, in human milk over 15 days was higher after vaccination with an mRNA-based vaccine than a vector-based vaccine (AUC with respect to ground [AUCg] ± the standard error of the mean [SEM] for IgA was 6·09 ± 0·89 in the BNT162b2 group, 7·48 ± 1·03 in the mRNA-1273 group, 4·17 ± 0·73 in the AZD1222 group, and 5·71 ± 0·70 in the Ad26.COV2.S group). Over a period of 70 days, the mean AUCg of both IgA and IgG was higher after vaccination with an mRNA-based vaccine than a vector-based vaccine (AUCg ± SEM for IgA was 38·77 ± 6·51 in the BNT162b2 group, 50·13 ± 7·41 in the mRNA-1273 group, 24·12 ± 5·47 in the AZD1222 group, and 28·15 ± 6·69 in the Ad26.COV2.S group; AUCg ± SEM for IgG was 40·43 ± 2·67 in the BNT162b2 group, 37·01 ± 2·38 in the mRNA-1273 group, 16·04 ± 5·09 in the AZD1222 group, and 10·44 ± 2·50 in the Ad26.COV2.S group).

INTERPRETATION

Overall, maternal vaccination during lactation with an mRNA-based vaccine resulted in higher SARS-CoV-2 antibody responses in human milk compared to vector-based vaccines. Therefore, vaccination with mRNA-based vaccines, preferably with the mRNA-1273 vaccine, might not only provide better immunological protection for the mother but also for her breastfed infant.

FUNDING

Stichting Steun Emma Kinderziekenhuis and the Amsterdam Infection and Immunity Institute (grant 24175).

Molecular alterations in human milk in simulated maternal nasal mucosal infection with live attenuated influenza vaccination

Breastfeeding protects against mucosal infections in infants. The underlying mechanisms through which immunity develops in human milk following maternal infection with mucosal pathogens are not well understood. We simulated nasal mucosal influenza infection through live attenuated influenza vaccination (LAIV) and compared immune responses in milk to inactivated influenza vaccination (IIV). Transcriptomic analysis was performed on RNA extracted from human milk cells to evaluate differentially expressed genes and pathways on days 1 and 7 post-vaccination. Both LAIV and IIV vaccines induced influenza-specific IgA that persisted for at least 6 months. Regulation of type I interferon production, toll-like receptor, and pattern recognition receptor signaling pathways were highly upregulated in milk on day 1 following LAIV but not IIV at any time point. Upregulation of innate immunity in human milk may provide timely protection against mucosal infections until antigen-specific immunity develops in the human milk-fed infant.

Feeding Twins with Human Milk and Factors Associated with Its Duration: A Qualitative and Quantitative Study in Southern Italy

BACKGROUND

Over the past year, there has been a rise in twin births. The current scientific consensus recommended breast-feed milk for all newborns for at least 6 months. They stated that it is possible to meet the nutritional needs of two or more newborns with only one mother's milk. More information would be desirable about the factors that influence or lead to the initiation and interruption of breastfeeding. The quality of the evidence available from multiple studies has been inconclusive and therefore led to controversial interpretations and practices.

AIMS

The first aim of this study was to analyze the extent of the feeding of multiples with breast milk in the experience of our clinical unit in terms of incidence and duration. The second objective was to evaluate the correlation between maternal, perinatal and neonatal variables with breast milk feeding rates and duration.

METHODS

The study was conducted between 2015 and 2020, in a NICU in Southern Italy (San Giovanni Rotondo, Foggia). Sixty-one women who have given birth to multiples were enrolled into the study. Newborn data were retrospectively collected by informatic database and breastfeeding information were collected by a questionnaire.

RESULTS

In our centre, the percentage of twins out of the total number of births over the years has almost doubled from 1.28% in 2015 to 2.48% in 2020 and the 88% of twins are premature. 18.1% received breast milk for more than 6 months and 6.3% received it for more than 12 months. Infants of lower gestational age and weight, born to multiparous, more mature and medium-high schooling mothers received breast milk for a longer period. 35% of women explained that the interruption of breastfeeding was due to the insufficient milk production and 41% to the stress and difficulties in managing the twins. Qualitative analysis of maternal narrative revealed, for many of them, the awareness of the importance of breastfeeding and the efforts made to try to give breast milk, but also fears about the quantity of milk and satiety of their children.

CONCLUSIONS

It is important to identify the factors both favoring and obstructing maternal milk feeding of multiples and it would be desirable the activation of a network of training and support for mothers after discharge, with particular regard to the categories found to be less inclined.

COVID-19 vaccination in pregnancy and postpartum

Pregnant women were excluded from the initial phase 3 clinical trials of COVID-19 vaccines resulting in limited data on their efficacy and safety during pregnancy and postpartum. As a result, since December 2020, there has been conflicting advice from public health, governmental, and professional authorities on this matter. From the end of 2020 up to now, some consensus guidance has been published with a prevalent precautionary approach on the administration of vaccines in pregnant women, in breastfeeding ones, or for those who are planning a pregnancy (either spontaneously or with assisted technologies). After the first few months of vaccine administration in some countries, more permissiveness seems to prevail, although with inconsistencies. Some little indicative advice, their inconsistency around the world and their changes in a short time have probably disoriented both women and their health care providers and placed the burden of decision making upon women and their health care providers without information to assist in making an informed choice. We reviewed the COVID-19 vaccination guidance for pregnant and breastfeeding women published to date and evidence from cases of unplanned pregnancy during the course of vaccine trials, preclinical experimental and observational clinical studies, and discuss their implications. In this way, we have tried to identify the safety of COVID-19 vaccines for pregnant or breastfeeding women, and their offspring.

Epitope-Specific Response of Human Milk Immunoglobulins in COVID-19 Recovered Women

The breastfeeding of infants by mothers who are infected with SARS-CoV-2 has become a dramatic healthcare problem. The WHO recommends that infected women should not abandon breastfeeding; however, there is still the risk of contact transmission. Convalescent donor milk may provide a defense against the aforementioned issue and can eliminate the consequences of artificial feeding. Therefore, it is vital to characterize the epitope-specific immunological landscape of human milk from women who recovered from COVID-19. We carried out a comprehensive ELISA-based analysis of blood serum and human milk from maternity patients who had recovered from COVID-19 at different trimesters of pregnancy. It was found that patients predominantly contained SARS-CoV-2 N-protein-specific immunoglobulins and had manifested the antibodies for all the antigens tested in a protein-specific and time-dependent manner. Women who recovered from COVID-19 at trimester I-II showed a noticeable decrease in the number of milk samples with sIgA specific to the N-protein, linear NTD, and RBD-SD1 epitopes, and showed an increase in samples with RBD conformation-dependent sIgA. S-antigens were found to solely induce a sIgA1 response, whereas N-protein sIgA1 and sIgA2 subclasses were involved in 100% and 33% of cases. Overall, the antibody immunological landscape of convalescent donor milk suggests that it may be a potential defense agent against COVID-19 for infants, conferring them with a passive immunity.

COVID-19 vaccination in pregnancy and postpartum

AIM

To identify whether COVID-19 vaccines should be administered in pregnant and breastfeeding women by reviewing the guidance and other evidence.

METHODS

We reviewed the COVID-19 vaccination guidance for pregnant and breastfeeding women published to date and evidence from preclinical experimental and observational clinical studies, and discuss their implications.

RESULTS

Pregnant women were excluded from the initial phase 3 clinical trials of COVID-19 vaccines resulting in limited data on their efficacy and safety during pregnancy and postpartum. As a result, since December 2020, there has been conflicting advice from public health, governmental, and professional authorities on this matter. From the end of 2020 up to now, some consensus guidance has been published with a prevalent precautionary approach on the administration of vaccines in pregnant women, in breastfeeding ones, or for those who are planning a pregnancy (either spontaneously or with assisted technologies). After the first few months of vaccine administration in some countries, more permissiveness seems to prevail, although with inconsistencies. At the moment, the results obtained by preclinical experimental and observational clinical studies suggest that the risks of the maternal COVID-19 outweigh the undocumented and hypothetical risks of the COVID-19 vaccines in pregnancy. Also, until two viral vector COVID-19 vaccines were associated with very rare thromboembolic events, all guidance had agreed that all approved COVID-19 vaccines could be administered in pregnancy. Actually, some concern has been expressed.

CONCLUSION

COVID-19 vaccines administered in pregnancy can reduce the risk of severe COVID-19 and their serious consequences for mothers and their offspring. However, many aspects remain to be clarified.