Characterization of SARS-CoV-2 RNA, Antibodies, and Neutralizing Capacity in Milk Produced by Women with COVID-19

Factors Influencing Breast Milk Antibody Titers during the Coronavirus Disease 2019 Pandemic: An Observational Study

The COVID-19 pandemic has highlighted the role of breastfeeding in providing passive immunity to infants via specific anti-SARS-CoV-2 antibodies in breast milk. We aimed to quantify these antibodies across different lactation stages and identify influencing factors. This prospective study involved mother-child dyads from Innsbruck University Hospital, Austria, with a positive maternal SARS-CoV-2 test during pregnancy or peripartum between 2020 and 2023. We collected breast milk samples at various lactation stages and analyzed anti-Spike S1 receptor-binding domain (S1RBD) immunoglobulins (Ig). Maternal and neonatal data were obtained from interviews and medical records. This study included 140 mothers and 144 neonates. Anti-S1RBD-IgA (72.0%), -IgG (86.0%), and -IgM (41.7%) were highly present in colostrum and decreased as milk matured. Mothers with natural infection and vaccination exhibited higher anti-S1RBD-IgA and -IgG titers in all milk stages. Mothers with moderate to severe infections had higher concentrations of anti-S1RBD-IgA and -IgG in transitional milk and higher anti-S1RBD-IgA and -IgM in mature milk compared to those with mild or asymptomatic infections. Variations in antibody responses were also observed with preterm birth and across different virus waves. This study demonstrates the dynamic nature of breast milk Ig and underscores the importance of breastfeeding during a pandemic.

Specific IgA, But Not IgG, in Human Milk From COVID-19-Infected Mothers Neutralizes SARS-CoV-2

This study highlights the importance of human milk in providing anti-severe acute respiratory syndrome coronavirus 2 immunity to newborns. The highest protective activity of human milk against COVID-19 was found in colostrum from infected mothers. Neutralizing activity was associated with high levels of specific IgA. Depletion of IgA, but not IgG, from milk samples completely abolished the ability of human milk to neutralize severe acute respiratory syndrome coronavirus 2.

Neonatal and infant infection with SARS-CoV-2

Despite the substantial body of investigative work describing the Coronavirus Disease 2019 (COVID-19) pandemic, its impact on neonates and infants remains less well characterized. Here, we review the data on epidemiology of COVID-19 in this population. Widespread use of universal testing for SARS-CoV-2 among pregnant persons presenting for delivery complicates interpretation of the risks of perinatal exposure. While many neonates and infants with COVID-19 are well-appearing or have only mild signs of illness, factors such as preterm birth, low birth weight, and medical comorbidities increase the risk of severe infection. We highlight potential protective maternal factors, summarize treatment options and discuss vaccine development. Higher quality data are needed to better inform our understanding of COVID-19 in neonates and infants.

Challenges of breastfeeding during COVID-19 and baby friendly protocols adopted at a maternity health center in the northern Emirates of UAE: a comprehensive review

BACKGROUND

The outbreak of Coronavirus disease (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) has caused worldwide panic in the global population taking people's lives, creating fear, and affecting mother-child relationships. Many questions were raised on the dangers of being infected with COVID-19 for newborns and safety concerns during feeding by COVID-19-positive mothers. Moreover, questions and doubts about the safety of the administration of vaccinations for nursing mothers are still open. This review attempts to fill the existing literature gap by exploring concepts concerning COVID-19 and breastfeeding mothers, the safety of vaccinations, the beneficial effects of breastfeeding on both mother and child, important hygiene recommendations for SARS-CoV-2 infected mothers, and possible solutions to optimize breastfeeding and safety precautions amidst the fear of emergence of novel variants.

METHODS

All relevant publications from Google Scholar, PubMed, Web of Science, and Scopus search engines from December 2019 to October 2022 related to SARS-CoV-2, breastfeeding, COVID-19, lactating guidelines, and vaccination were included using 'Breastfeeding AND vaccine AND SARS-CoV-2' as MESH TERMS. Apart from the literature review, existing maternity protocols followed in Northern UAE were gathered from lactation consultants practicing in the UAE.

RESULTS

Out of 19,391 records generated, only 24 studies were analyzed and summarized in this exhaustive review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow chart. Previous studies suggest that breastmilk is predominantly the primary source of nutrition for neonates. Breast milk is a rich source of antibodies that help the baby to fight against infections including other benefits. Hygiene recommendations for suspected or confirmed COVID-19-infected mothers are required along with psychological and emotional support.

CONCLUSIONS

The administration of vaccinations should be advised and encouraged to protect the mothers with antibodies and the neonates by the passive transmission of antibodies through breast milk. This is a significant reason for not stopping breastfeeding even in case of COVID-19 infection. With adherence to proper hygiene methods, breastfeeding is recommended to be continued as the benefits greatly outweigh the risks.

Skilled lactation support using telemedicine in the neonatal intensive care unit

BACKGROUND

NICU mothers face unique challenges in initiating and sustaining breastfeeding, but previous studies have focused on outpatient breastfeeding support. We conducted a retrospective study of NICU breastfeeding outcomes before and after implementing telelactation.

METHODS

Pre-Telemedicine mothers received in-person support by NICU lactation consultants, while Telemedicine mothers received solely telemedicine consults after maternal discharge.

RESULTS

Exclusive breastmilk feeding at discharge increased in the Telemedicine group. Notably, babies in the Telemedicine cohort who were fed any formula on admission experienced significant improvement in exclusive breastmilk feeding at discharge, and those whose mothers received at least one NICU lactation consult had the greatest improvement in exclusive breastfeeding rates at discharge.

CONCLUSIONS

This study is the first to validate the use of telemedicine as a means of maintaining access to skilled lactation support in the NICU when in-person consults are not feasible. Incorporating telemedicine can ensure access and continuity of skilled lactation support, and sustain breastfeeding rates.

Post-discharge Care Practices, Challenges, and Outcomes in Newborn Infants of Mothers With SARS-CoV-2 Infection: Insights From Public Hospitals

Background The data regarding the care at home and outcomes in infants of mothers infected with SARS-CoV-2 continue to evolve. There is a paucity of studies beyond the immediate newborn period. Our research aims to improve the understanding in these areas by studying the newborn population discharged from public hospitals in several boroughs of New York City (NYC) through the first year of the COVID-19 pandemic. Objective The objective of this study is to assess parental perspective and describe post-discharge care practices, patterns of healthcare utilization, challenges in obtaining care, and outcomes in infants between six and 12 months of age born to mothers infected with SARS-CoV-2 at the time of delivery. Methods We conducted an institutional review board (IRB)-approved multi-center retrospective cohort study of infants born to SARS-CoV-2-positive mothers at five NYC public hospitals between March and December of 2020. Clinical and demographic data were collected from electronic medical records. A phone interview of the caregivers using a standard questionnaire was conducted to collect data about care at home, healthcare utilization patterns, and challenges with access to healthcare. Results Our study cohort included 216 infants born to SARS-CoV-2-positive mothers with 16 (7.4%) mothers being symptomatic at discharge. Ten infants tested positive, and two showed symptoms before discharge. Two hundred seven (95.8%) infants were discharged home to their parents, and eight (3.7%) were transferred to other facilities. One hundred thirty-eight (66%) infants had at least one visit to the emergency room (ER) for various complaints where two were found to have COVID-19 with one needing hospitalization. One hundred seventy-two (79.6%) families responded to the phone interview. Most mothers (78%) cohabitated with their infants at home, and 70.3% elected to breastfeed. However, only 56.3% of mothers reported using all the recommended infection prevention practices at home. More than half (57%) of the families reported financial hardship related to the pandemic. Although 46.2% of patients missed their in-person health maintenance visits, telemedicine was highly utilized for follow-up with most being phone visits (70.3%). The majority of the infants (95.5%) remained up-to-date with their routine immunizations. Conclusions Our results suggest that infants born to SARS-CoV-2-infected mothers showed increased utilization of medical care and telemedicine between six and 12 months of age. Mothers reported low adherence to infection prevention practices at home; however, infants rarely showed clinically significant SARS-CoV-2 infection while maintaining high breastfeeding rates after discharge.

Prevalence and duration of SARS-CoV-2 fecal shedding in breastfeeding dyads following maternal COVID-19 diagnosis

Background

There is a paucity of data on the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in feces of lactating women with coronavirus disease 2019 (COVID-19) and their breastfed infants as well as associations between fecal shedding and symptomatology.

Objective

We examined whether and to what extent SARS-CoV-2 is detectable in the feces of lactating women and their breastfed infants following maternal COVID-19 diagnosis.

Methods

This was a longitudinal study carried out from April 2020 to December 2021 involving 57 breastfeeding maternal-infant dyads: 33 dyads were enrolled within 7 d of maternal COVID-19 diagnosis, and 24 healthy dyads served as controls. Maternal/infant fecal samples were collected by participants, and surveys were administered via telephone over an 8-wk period. Feces were analyzed for SARS-CoV-2 RNA.

Results

Signs/symptoms related to ears, eyes, nose, and throat (EENT); general fatigue/malaise; and cardiopulmonary signs/symptoms were commonly reported among mothers with COVID-19. In infants of mothers with COVID-19, EENT, immunologic, and cardiopulmonary signs/symptoms were most common, but prevalence did not differ from that of infants of control mothers. SARS-CoV-2 RNA was detected in feces of 7 (25%) women with COVID-19 and 10 (30%) of their infants. Duration of fecal shedding ranged from 1-4 wk for both mothers and infants. SARS-CoV-2 RNA was sparsely detected in feces of healthy dyads, with only one mother's and two infants' fecal samples testing positive. There was no relationship between frequencies of maternal and infant SARS-CoV-2 fecal shedding (P=0.36), although presence of maternal or infant fever was related to increased likelihood (7-9 times greater, P≤0.04) of fecal shedding in infants of mothers with COVID-19.

Epidemiology of COVID-19 in Infants in the United States: Incidence, Severity, Fatality, and Variants of Concern

BACKGROUND

The clinical spectrum of infant COVID-19 ranges from asymptomatic infection to life-threatening illness, yet epidemiologic surveillance has been limited for infants.

METHODS

Using COVID-19 case data (restricted to reporting states) and national mortality data, we calculated incidence, hospitalization, mortality and case fatality rates through March 2022.

RESULTS

Reported incidence of COVID-19 was 64.1 new cases per 1000 infant years (95% CI: 63.3-64.9). We estimated that 594,012 infants tested positive for COVID-19 nationwide by March 31, 2022. Viral variant comparisons revealed that incidence was 7× higher during the Omicron (January-March 2022) versus the pre-Delta period (June 2020-May 2021). The cumulative case hospitalization rate was 4.1% (95% CI: 4.0%-4.3%). For every 74 hospitalized infants, one infant death occurred, but overall COVID-19-related infant case fatality was low, with 7.0 deaths per 10,000 cases (95% CI: 5.6-8.7). Nationwide, 333 COVID-19 infant deaths were reported. Only 13 infant deaths (3.9%) were the result of usually lethal congenital anomalies. The majority of infant decedents were non-White (28.2% Black, 26.1% Hispanic, 8.1% Asian, Indigenous or multiracial).

CONCLUSIONS

More than half a million US infants contracted COVID-19 by March 2022. Longitudinal assessment of long-term infant SARS-CoV-2 infection sequelae remains a critical research gap. Extremely low infant vaccination rates (<5%), waning adult immunity and continued viral exposure risks suggest that infant COVID-19 will remain a persistent public health problem. Our study underscores the need to increase vaccination rates for mothers and infants, decrease viral exposure risks and improve health equity.

Assessing the Knowledge and Attitudes of Breastfeeding During the COVID-19 Pandemic

Background It is generally accepted that breastfeeding is a practice that provides valuable health benefits to both mother and baby. However, the COVID-19 pandemic unveiled questions regarding the safety of breastfeeding, leading to potential hesitation among the public. Our study seeks to appreciate the public's understanding and attitudes toward breastfeeding during the COVID-19 pandemic. Methods An anonymous survey was distributed online through social media platforms. Demographic information was collected with questions specifically analyzing the knowledge and attitude of each participant. Calculations were performed using Spearman's rho correlations to determine significant differences. Results Thirty-nine women were recruited. The average overall knowledge score was 93% correct. 87% of participants believe breastfeeding is better than formula feeding, and 92% stated they would breastfeed their infant if they knew it could protect their child from COVID-19. Discussion The results of our study indicated that although overall knowledge of breastfeeding during the COVID-19 pandemic was well understood, higher levels of education may play a role in the depth of one's knowledge. In addition, while participants were reporting high levels of education about breastfeeding from their healthcare providers, few were receiving data specific to the pandemic. The data gathered from this study may help to target future educational initiatives.

SARS-CoV-2 antibodies and their neutralizing capacity against live virus in human milk after COVID-19 infection and vaccination: prospective cohort studies

BACKGROUND

There is limited understanding of the impact of coronavirus disease 2019 (COVID-19) infection and vaccination type and interval on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) human milk antibodies and their neutralizing capacity.

OBJECTIVES

These cohort studies aimed to determine the presence of antibodies and live virus neutralizing capacity in milk from females infected with COVID-19, unexposed milk bank donors, and vaccinated females and examine impacts of vaccine interval and type.

METHODS

Milk was collected from participants infected with COVID-19 during pregnancy or lactation (Cohort-1) and milk bank donors (Cohort-2) from March 2020-July 2021 at 3 sequential 4-wk intervals and COVID-19 vaccinated participants with varying dose intervals (Cohort-3) (January-October 2021). Cohort-1 and Cohort-3 were recruited from Sinai Health (patients) and through social media. Cohort-2 included Ontario Milk Bank donors. Milk was examined for SARS-CoV-2 antibodies and live virus neutralization.

RESULTS

Of females with COVID-19, 53% (Cohort-1, n = 55) had anti-SARS-CoV-2 IgA antibodies in ≥1 milk sample. IgA+ samples (40%) were more likely neutralizing than IgA- samples (odds ratio [OR]: 2.18; 95% confidence interval [CI]: 1.03, 4.60; P = 0.04); however, 25% of IgA- samples were neutralizing. Both IgA positivity and neutralization decreased ∼6 mo after symptom onset (0-100 compared with 201+ d: IgA OR: 14.30; 95% CI: 1.08, 189.89; P = 0.04; neutralizing OR: 4.30; 95% CI: 1.55, 11.89; P = 0.005). Among milk bank donors (Cohort-2, n = 373), 4.3% had IgA antibodies; 23% of IgA+ samples were neutralizing. Vaccination (Cohort-3, n = 60) with mRNA-1273 and shorter vaccine intervals (3 to <6 wk) resulted in higher IgA and IgG than BNT162b2 (P < 0.04) and longer intervals (6 to <16 wk) (P≤0.02), respectively. Neutralizing capacity increased postvaccination (P = 0.04) but was not associated with antibody positivity.

CONCLUSIONS

SARS-CoV-2 infection and vaccination (type and interval) impacted milk antibodies; however, antibody presence did not consistently predict live virus neutralization. Although human milk is unequivocally the best way to nourish infants, guidance on protection to infants following maternal infection/vaccination may require more nuanced messaging. This study was registered at clinicaltrials.gov as NCT04453969 and NCT04453982.

Anti-SARS-CoV-2-specific antibodies in human breast milk following SARS-CoV-2 infection during pregnancy: a prospective cohort study

BACKGROUND

While the presence of SARS-CoV-2 in human breast milk is contentious, anti-SARS-CoV-2 antibodies have been consistently detected in human breast milk. However, it is uncertain when and how long the antibodies are present.

METHODS

This was a prospective cohort study including all consecutive pregnant women with confirmed SARS-CoV-2 infection during pregnancy, recruited at six maternity units in Spain and Hong Kong from March 2020 to March 2021. Colostrum (day of birth until day 4 postpartum) and mature milk (day 7 postpartum until 6 weeks postpartum) were prospectively collected, and paired maternal blood samples were also collected. Colostrum samples were tested with rRT-PCR-SARS-CoV-2, and skimmed acellular milk and maternal sera were tested against SARS-CoV-2 specific immunoglobulin M, A, and G reactive to receptor binding domain of SARS-CoV-2 spike protein 1 to determine the presence of immunoglobulins. Then, we examined how each immunoglobulin type in the colostrum was related to the time of infection by logistic regression analysis, the concordance between these immunoglobulins in the colostrum, maternal serum, and mature milk by Cohen's kappa statistic, and the relationship between immunoglobulin levels in mature milk and colostrum with McNemar.

RESULTS

One hundred eighty-seven pregnant women with confirmed SARS-CoV-2 infection during pregnancy or childbirth were recruited and donated the milk and blood samples. No SARS-CoV-2 was found in the human breast milk. Immunoglobulin A, G, and M were present in 129/162 (79·6%), 5/163 (3·1%), and 15/76 (19·7%) colostrum samples and in 17/62 (27·42%), 2/62 (3·23%) and 2/62 (3·23%) mature milk samples, respectively. Immunoglobulin A was the predominant immunoglobulin found in breast milk, and its levels were significantly higher in the colostrum than in the mature milk (p-value < 0.001). We did not find that the presence of immunoglobulins in the colostrum was associated with their presence in maternal, the severity of the disease, or the time when the infection had occurred.

CONCLUSIONS

Since anti-SARS-CoV-2 antibodies are found in the colostrum irrespective of the time of infection during pregnancy, but the virus itself is not detected in human breast milk, our study found no indications to withhold breastfeeding, taking contact precautions when there is active disease.

A case series exploring the human milk polyclonal IgA1 response to repeated SARS-CoV-2 vaccinations by LC-MS based fab profiling

Introduction

Upon vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) humans will start to produce antibodies targeting virus specific antigens that will end up in circulation. In lactating women such antibodies will also end up in breastmilk, primarily in the form of secretory immunoglobulin A1 (SIgA1), the most abundant immunoglobulin (Ig) in human milk. Here we set out to investigate the SIgA1 clonal repertoire response to repeated SARS-CoV-2 vaccination, using a LC-MS fragment antigen-binding (Fab) clonal profiling approach.

Methods

We analyzed the breastmilk of six donors from a larger cohort of 109 lactating mothers who received one of three commonly used SARS-CoV-2 vaccines. We quantitatively monitored the SIgA1 Fab clonal profile over 16 timepoints, from just prior to the first vaccination until 15  days after the second vaccination.

Results

In all donors, we detected a population of 89-191 vaccine induced clones. These populations were unique to each donor and heterogeneous with respect to individual clonal concentrations, total clonal titer, and population size. The vaccine induced clones were dominated by persistent clones (68%) which came up after the first vaccination and were retained or reoccurred after the second vaccination. However, we also observe transient SIgA1 clones (16%) which dissipated before the second vaccination, and vaccine induced clones which uniquely emerged only after the second vaccination (16%). These distinct populations were observed in all analyzed donors, regardless of the administered vaccine.

Discussion

Our findings suggest that while individual donors have highly unique human milk SIgA1 clonal profiles and a highly personalized SIgA1 response to SARS-CoV-2 vaccination, there are also commonalities in vaccine induced responses.

SARS-CoV-2 neutralizing antibody titers in maternal blood, umbilical cord blood, and breast milk

OBJECTIVE

We quantified neutralizing SARS-CoV-2 antibody against spike protein (nAb) levels after vaccination and SARS-CoV-2 infection in maternal serum, cord blood, and breast milk and determined whether they correlate with levels of spike protein binding antibody.

STUDY DESIGN

Women (n = 100) were enrolled on admission for delivery. Previous SARS-CoV-2 infection was defined by anti-nucleocapsid antibodies. Levels of nAb and binding antibodies against spike receptor binding domain were measured in maternal blood, cord blood, and milk.

RESULTS

Maternal nAb levels were higher after vaccine and infection than vaccine alone but waned rapidly. Levels of nAb in cord blood and milk correlated with maternal levels and were higher in cord blood than maternal. Spike protein binding antibody levels correlated with nAb.

CONCLUSION

SARS-CoV-2 vaccination near delivery may boost antibody-mediated immunity in the peripartum period. Neutralizing antibodies are passed transplacentally and into milk. Spike protein binding antibody may be a feasible proxy for nAb.

A narrative review of COVID-19 vaccination in pregnancy and breastfeeding

The Coronavirus pandemic has affected millions of people due to the spread of the Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) virus. Pregnant individuals and infants are most vulnerable given the increased risk of developing severe complications from SARS-CoV-2 infection. Recently, COVID-19 vaccination is recommended for pregnant women and infants starting at 6 months of age to prevent disease contraction and minimize disease severity. We conducted a review of the literature on COVID-19 vaccination to discuss vaccine safety and efficacy, immunity after maternal vaccination, transplacental transfer and persistence of antibodies, and public health implications. Current evidence supports the safety and efficacy of vaccination during pregnancy. Maternal vaccination provides greater antibody persistence in infants compared to immunity from natural infection. Furthermore, vaccination has demonstrated an increased rate of passive antibody transfer through the placenta and breast milk. Public health interventions are important in achieving herd immunity and ultimately ending the pandemic. IMPACT: This article highlights the benefits of COVID-19 vaccination during pregnancy with a review of the data describing safety and efficacy, passive and active immunity after maternal immunization, trans-placental transfer and persistence of protective antibodies, and public health implications. With this information, healthcare providers can provide up-to-date knowledge to their pregnant patients to help them form an informed decision on vaccination and combat vaccine hesitancy.

Infectious virus shedding duration reflects secretory IgA antibody response latency after SARS-CoV-2 infection

Infectious virus shedding from individuals infected with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is used to estimate human-to-human transmission risk. Control of SARS-CoV-2 transmission requires identifying the immune correlates that protect infectious virus shedding. Mucosal immunity prevents infection by SARS-CoV-2, which replicates in the respiratory epithelium and spreads rapidly to other hosts. However, whether mucosal immunity prevents the shedding of the infectious virus in SARS-CoV-2-infected individuals is unknown. We examined the relationship between viral RNA shedding dynamics, duration of infectious virus shedding, and mucosal antibody responses during SARS-CoV-2 infection. Anti-spike secretory IgA antibodies (S-IgA) reduced viral RNA load and infectivity more than anti-spike IgG/IgA antibodies in infected nasopharyngeal samples. Compared with the IgG/IgA response, the anti-spike S-IgA post-infection responses affected the viral RNA shedding dynamics and predicted the duration of infectious virus shedding regardless of the immune history. These findings highlight the importance of anti-spike S-IgA responses in individuals infected with SARS-CoV-2 for preventing infectious virus shedding and SARS-CoV-2 transmission. Developing medical countermeasures to shorten S-IgA response time may help control human-to-human transmission of SARS-CoV-2 infection and prevent future respiratory virus pandemics.

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.

SARS-CoV-2 Antibody Profiles in Maternal Serum and Breast Milk Following mRNA COVID-19 Vaccination: A Longitudinal Prospective Observational Cohort Study

COVID-19 vaccination during pregnancy protects infants against symptomatic COVID-19. Vaccination of lactating mothers may offer additional protection, but our understanding of immune responses in breast milk is limited. We, therefore, performed a single-center prospective cohort study of lactating mothers who received a COVID-19 mRNA primary vaccine series to evaluate the durability, breadth, and neutralizing capacity of the antibody responses in breast milk. Spike IgG- and IgA-binding antibodies of ancestral SARS-CoV-2 in serum and breast milk were quantified over 9 months using Meso Scale Discovery (MSD) V-PLEX assays, and ancestral titers were compared to four variants of concern (Alpha, Beta, Delta, Gamma) at a single time point. Neutralizing antibodies against ancestral SARS-CoV-2 and Omicron BA.4/5 were compared before and after vaccination using a pseudovirus-neutralization assay. Eleven lactating mothers received either Pfizer BNT162b2 (7/11) or Moderna mRNA-1273 (4/11) vaccine primary series. IgG and IgA titers increased in serum and breast milk following each dose, peaking 1-4 weeks after series completion. Titers remained significantly elevated for 7-9 months, except for in breast milk IgA which returned to baseline within 1 month. Furthermore, binding antibodies against all included variants were detected in breast milk collected 1-3 weeks after series completion. However, while vaccination induced a strong neutralizing response against ancestral SARS-CoV-2 in serum and more modest response in breast milk, it did not induce neutralizing antibodies against Omicron BA.4/5 in either specimen type. This study demonstrates that maternal COVID-19 mRNA vaccination may enhance immune protection for infants through breast milk via increased IgG- and IgA-binding-and-neutralizing antibodies; although, variant-specific boosters may be required to optimize immune protection.

Milk antibody response after 3rd COVID-19 vaccine and SARS-CoV-2 infection and implications for infant protection

Little is known about the persistence of human milk anti-SARS-CoV-2 antibodies after 2nd and 3rd vaccine doses and infection following 3rd dose. In this study, human milk, saliva, and blood samples were collected from 33 lactating individuals before and after vaccination and infection. Antibody levels were measured using ELISA and symptoms were assessed using questionnaires. We found that after vaccination, milk anti-SARS-CoV-2 antibodies persisted for up to 8 months. In addition, distinct patterns of human milk IgA and IgG production and higher milk RBD-blocking activity was observed after infection compared to 3-dose vaccination. Infected mothers reported more symptoms than vaccinated mothers. We examined the persistence of milk antibodies in infant saliva after breastfeeding and found that IgA was more abundant compared to IgG. Our results emphasize the importance of improving the secretion of IgA antibodies to human milk after vaccination to improve the protection of breastfeeding infants.

Breastmilk from COVID-19 negative lactating mothers shows neutralizing activity against SARS-COV-2

Breastmilk protects newborns from infections through specific and nonspecific compounds. This study investigated the neutralizing activity against SARS-CoV-2 of breastmilk from SARS-CoV-2 negative, unvaccinated mothers, and compared it to that from infected nursing mothers. We enrolled women after COVID-19 swab testing results upon maternity admission, and divided them into two groups: group A, COVID-19-positive mothers, and group B, negative mothers. Breastmilk was randomly sampled at 2, 7, and 20 days postpartum. We collected 19 samples for Group A and 41 for Group B. A microneutralization assay was used to determine the 50% neutralization (NT50) titre. The presence of neutralizing antibodies was also determined. Group A had 100% neutralizing samples at 2 days postpartum (T0), declining 7 days postpartum (T1) and 20 days postpartum (T2). Group B samples exhibited neutralizing activity mostly at 7 days postpartum (T1) (90%). Negative mothers' samples showed no correlation between NT50 titres and antibodies' presence, suggesting that non-specific breastmilk components may exert antiviral action against SARS-CoV-2.

Breastfeeding vs. breast milk transmission during COVID-19 pandemic, which is more important?

The catastrophic coronavirus disease 2019 (COVID-19) pandemic has raised many health questions, and whether breast milk from SARS-CoV-2 infected mothers may be a vector for SARS-CoV-2 transmission has become a hot topic of concern worldwide. Currently, there are extremely limited and conflicting data on the risk of infection in infants through breastfeeding. For this reason, we investigated almost all current clinical studies and systematically analyzed the presence of SARS-CoV-2 and antibodies in the breast milk of mothers infected with SARS-CoV-2, their effects on newborns, and the mechanisms involved. A total of 82 studies were included in this review, of which 66 examined the presence of SARS-CoV-2 in breast milk samples from mothers diagnosed with COVID-19, 29 reported results of antibody detection of SARS-CoV-2 in breast milk, and 13 reported both nucleic acid and antibody test results. Seventeen studies indicated the presence of detectable SARS-CoV-2 nucleic acid in breast milk samples, and only two studies monitored viral activity, both of which reported that infectious viruses could not be cultured from RNA-positive breast milk samples. All 29 studies indicated the presence of at least one of the three antibodies, IgA, IgG and IgM, in breast milk. Five studies indicated the presence of at least one antibody in the serum of breastfed newborns. No COVID-19-related deaths were reported in all 1,346 newborns. Our study suggests that direct breastfeeding does not pose an additional risk of infection to newborns and that breast milk is a beneficial source of anti-SARS-CoV-2 antibodies that provide passive immune protection to infants. In addition, direct breastfeeding would provide maternal benefits. Our review supports the recommendation to encourage direct breastfeeding under appropriate infection control guidelines. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier: 458043.

Colostrum Features of Active and Recovered COVID-19 Patients Revealed Using Next-Generation Proteomics Technique, SWATH-MS

Colostrum performs nutritional, anti-inflammatory and anti-infective functions and promotes immune system formation and organ development. The new coronavirus, SARS-CoV-2, has generated concerns about viral transmission through human milk, with a lack of evidence about human milk's protective effects against the infection. This study aimed at analyzing presence of the virus and at identifying the protein expression profile of human colostrum in active and COVID-19-recovered patients. Colostrum samples were collected from women with COVID-19 (n = 3), women recently recovered from the infection (n = 4), and non-infected women (n = 5). The samples were analyzed by means of RT-qPCR to determine presence of the virus and using SWATH-MS for proteomic analysis. Proteomic results were then analyzed using bioinformatic methods. The viral tests were negative for SARS-CoV-2 in the colostrum from COVID-19 patients. The proteomic analysis identified 301 common proteins in all samples analyzed. Nineteen proteins were upregulated and 7 were downregulated in the COVID-19 group versus the control samples, whereas 18 were upregulated and 7 were downregulated when comparing the COVID-19 group to the recovered group. Eleven proteins were biomarkers of active COVID-19 infection. Ten were upregulated: ACTN1, CD36, FAM3B, GPRC5B, IGHA2, IGK, PLTP, RAC1, SDCBP and SERPINF1, and one was downregulated: PSAP. These proteins are mainly related to immunity, inflammatory response and protein transport. In conclusion, the results of this study suggest that colostrum is not a vehicle for mother-to-child SARS-CoV-2 transmission. Moreover, the colostrum's proteome of active and recuperated patients indicate that it could provide immune benefits to infants.

Physical activity in lactating women influences SARS-CoV-2-specific antibodies in human milk

Background

Moderate exercise results in a significant increase in serum and salivary immunoglobulins. Maternal physical activity might therefore also be a factor influencing antibody levels in human milk. This study aims to determine the influence of physical activity on SARS-CoV-2-specific Immunoglobulin A (IgA) in human milk and Immunoglobulin G (IgG) in serum.

Methods

In this prospective cross-sectional cohort study, all lactating women in the Netherlands were eligible to participate. SARS-CoV-2-specific IgA in human milk and IgG in serum were determined using an enzyme-linked immunosorbent assay (ELISA). Data on performed physical activity was collected using the Short Questionnaire to Assess Health enhancing physical activity (SQUASH), which includes intensity and duration of the performed activity.

Findings

In total, 356 out of 2312 lactating women tested positive for SARS-CoV-2-specific antibodies in serum. Of them, 323 filled in the questionnaire and were included in the analysis. An association between the activity score and SARS-CoV-2-specific antibodies in human milk (B = 1·035, 95·0% CI = 1·019 to 1·052, p = 0·042) and serum (B = 1·019, 95·0% CI = 1·009 to 1·029, p = 0·048) was demonstrated. No association was found between the duration of physical activity and SARS-CoV-2-specific antibodies in human milk or serum.

Interpretation

Our findings suggest that physical activity is beneficial for the levels of SARS-CoV-2-specific antibodies in human milk and serum, with the intensity of the physical activity being the most important contributor to this relationship. A higher level of antibodies in human milk might provide better immunological protection for infants against COVID-19.

Vertical transmission and maternal passive immunity post-SARS-CoV-2

Since 2020, the highly contagious nature and various transmission routes of SARS-CoV-2 have rendered the pandemic interminable. Vertical transmission (VT) through the placenta and breast milk, which is frequent for certain virus types, is thought to exist for SARS-CoV-2 and is hypothesized by many researchers. Conversely, antibodies are produced to counteract the effect of viruses. Since newborns' immunologic system cannot produce proper antibodies, maternal antibodies are usually transferred from mother to infant/fetus to meet the need. This theory leads to the hypothesis of transmission of antibodies through the placenta and breast milk following SARS-CoV-2 infection or vaccination. This paper further discusses these hypotheses, considering consequences of fetus/infant harm versus benefit.

The Secretory IgA Response in Human Milk Against the SARS-CoV-2 Spike Is Highly Durable and Neutralizing for At Least 1 Year of Lactation Postinfection

Background: Although in the early pandemic period COVID-19 pathology among young children and infants was typically less severe compared with that observed among adults, this has not remained entirely consistent as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have emerged. There is an enormous body of evidence demonstrating the benefits of human milk antibodies (Abs) in protecting infants against a wide range of enteric and respiratory infections. It is highly plausible that the same holds true for protection against SARS-CoV-2 as this virus infects cells of the gastrointestinal and respiratory mucosae. Understanding the durability of a human milk Ab response over time after infection is critical. Objective: Previously, we examined the Abs present in milk of those recently infected with SARS-CoV-2 and concluded that the response was secretory immunoglobulin A (sIgA) dominant and that these titers were highly correlated with neutralization potency. The present study aimed to monitor the durability of the SARS-CoV-2 IgA and secretory Ab (sAb) response in milk from COVID-19-recovered lactating individuals over 12 months in the absence of vaccination or reinfection. Results: This analysis revealed a robust and durable spike-specific milk sIgA response, and at 9-12 months after infection, 88% of the samples exhibited titers above the positive cutoff for IgA and 94% were above the cutoff for sAb. Fifty percent of participants exhibited less than twofold reduction of spike-specific IgA through 12 months. A strong, significant positive correlation between IgA and sAb against spike persisted throughout the study period. Nucleocapsid-specific Abs were also assessed, which revealed significant background or cross-reactivity of milk IgA against this immunogen, as well as limited/inconsistent durability compared with Spike titers. Conclusion: These data suggest that lactating individuals are likely to continue producing spike-specific Abs in their milk for 1 year or more, which may provide critical passive immunity to infants against SARS-CoV-2 throughout the lactation period.

Assessment of SARS-CoV-2 neutralizing antibody titers in breastmilk from convalescent and vaccinated mothers

Breastmilk contains antibodies that could protect breastfed infants from infections. In this work, we examined if antibodies in breastmilk could neutralize SARS-CoV-2 in 84 breastmilk samples from women that were either vaccinated (Comirnaty, mRNA-1273, or ChAdOx1), infected with SARS-CoV-2, or both infected and vaccinated. The neutralization capacity of these sera was tested using pseudotyped vesicular stomatitis virus carrying either the Wuhan-Hu-1, Delta, or BA.1 Omicron spike proteins. We found that natural infection resulted in higher neutralizing titers and that neutralization correlated positively with levels of immunoglobulin A in breastmilk. In addition, significant differences in the capacity to produce neutralizing antibodies were observed between both mRNA-based vaccines and the adenovirus-vectored ChAdOx1 COVID-19 vaccine. Overall, our results indicate that breastmilk from naturally infected women or those vaccinated with mRNA-based vaccines contains SARS-CoV-2 neutralizing antibodies that could potentially provide protection to breastfed infants from infection.

Breastfeeding during the COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused many significant changes to all aspects of day to day life. The disease has spread and reached pandemic proportions. The principle route of transmission is the respiratory route. Infants, pregnant women and breastfeeding mothers have all been affected. Many interventions and guidelines from important societies have been instituted in order to curb the transmission of the disease. These have involved both pharmacological and non-pharmacological methods. COVID-19 vaccines have also emerged as important methods of primary prevention of the disease. But several questions have been raised concerning the safety and efficacy of their use in pregnant and breastfeeding mothers. It has also not been clear if the vaccines are effective in generating a robust immune response in the pregnant women and breastfeeding mothers to confer passive immunity to the fetuses and infants, respectively. And they have not been tested in infants. The aspect of infant feeding has equally been affected. Although breast milk has not been known to serve as the vehicle of transmission of the virus, there is still some lack of uniformity of practice regarding breastfeeding when a mother has SARS-CoV-2 infection. This has led to infant feeding being done by the use of commercial formula feeds, pasteurized human donor breast milk, feeding on the mother's own expressed breast milk by a care giver and directly breastfeeding with skin to skin contact. This is despite breast milk being the most physiologically appropriate type of feed for infants. Therefore the pertinent question remains; should breastfeeding continue during the pandemic continue? This review also seeks to analyse the vast amount of scientific information regarding the subject and to synthesize science-based information.

Prenatal SARS-CoV-2 infection alters postpartum human milk-derived extracellular vesicles

Human milk-derived extracellular vesicles (HMEVs) are crucial functional components in breast milk, contributing to infant health and development. Maternal conditions could affect HMEV cargos; however, the impact of SARS-CoV-2 infection on HMEVs remains unknown. This study evaluated the influence of SARS-CoV-2 infection during pregnancy on postpartum HMEV molecules. Milk samples (9 prenatal SARS-CoV-2 vs. 9 controls) were retrieved from the IMPRINT birth cohort. After defatting and casein micelle disaggregation, 1 mL milk was subjected to a sequential process of centrifugation, ultrafiltration, and qEV-size exclusion chromatography. Particle and protein characterizations were performed following the MISEV2018 guidelines. EV lysates were analyzed through proteomics and miRNA sequencing, while the intact EVs were biotinylated for surfaceomic analysis. Multi-Omics was employed to predict HMEV functions associated with prenatal SARS-CoV-2 infection. Demographic data between the prenatal SARS-CoV-2 and control groups were similar. The median duration from maternal SARS-CoV-2 test positivity to milk collection was 3 months (range: 1-6 months). Transmission electron microscopy showed the cup-shaped nanoparticles. Nanoparticle tracking analysis demonstrated particle diameters of <200 nm and yields of >1e11 particles from 1 mL milk. Western immunoblots detected ALIX, CD9 and HSP70, supporting the presence of HMEVs in the isolates. Thousands of HMEV cargos and hundreds of surface proteins were identified and compared. Multi-Omics predicted that mothers with prenatal SARS-CoV-2 infection produced HMEVs with enhanced functionalities involving metabolic reprogramming and mucosal tissue development, while mitigating inflammation and lower EV transmigration potential. Our findings suggest that SARS-CoV-2 infection during pregnancy boosts mucosal site-specific functions of HMEVs, potentially protecting infants against viral infections. Further prospective studies should be pursued to reevaluate the short- and long-term benefits of breastfeeding in the post-COVID era.

Detection of SARS-CoV-2 IgA and IgG in human milk and breastfeeding infant stool 6 months after maternal COVID-19 vaccination

OBJECTIVE

Assess presence, durability, and neutralization capacity of SARS-CoV-2-specific antibodies in breastfeeding infants' stool, mother's plasma and milk following maternal vaccination.

DESIGN

Thirty-seven mothers and 25 infants were enrolled between December 2020 and November 2021 for this prospective observational study. All mothers were vaccinated during lactation except three, which were vaccinated during pregnancy. Milk, maternal plasma, and infants' stool was collected pre-vaccination and at periods up to 6 months following COVID-19 vaccine series initiation/completion. SARS-CoV-2 antibody levels and their neutralization capacities were assessed.

RESULTS

SARS-CoV-2-specific IgA and IgG levels were higher in infant stool post-maternal vaccination amongst milk-fed compared to controls. Maternal SARS-CoV-2-specific IgA and IgG concentrations decreased over 6 months post-vaccination but remained higher than pre-vaccination levels. We observed improved neutralization capacity in milk and plasma after COVID-19 vaccination.

CONCLUSIONS

The presence of SARS-CoV-2-specific antibodies in infant stool following maternal vaccination offers further evidence of the lasting transfer of these antibodies through breastfeeding.

The secretory IgA (sIgA) response in human milk against the SARS-CoV-2 Spike is highly durable and neutralizing for at least 1 year of lactation post-infection

Although in the early pandemic period, COVID-19 pathology among young children and infants was typically less severe compared to that observed among adults, this has not remained entirely consistent as SARS-CoV-2 variants have emerged. There is an enormous body of evidence demonstrating the benefits of human milk antibodies (Abs) in protecting infants against a wide range of enteric and respiratory infections. It is highly plausible that the same holds true for protection against SARS-CoV-2, as this virus infects cells of the gastrointestinal and respiratory mucosae. Understanding the durability of a human milk Ab response over time after infection is critical. Previously, we examined the Abs present in milk of those recently infected with SARS-CoV-2, and concluded that the response was secretory IgA (sIgA)-dominant and that these titers were highly correlated with neutralization potency. The present study aimed to monitor the durability of the SARS-CoV-2 IgA and secretory Ab (sAb) response in milk from COVID-19-recovered lactating individuals over 12 months, in the absence of vaccination or re-infection. This analysis revealed a robust and durable Spike-specific milk sIgA response, that at 9-12 months after infection, 88% of the samples exhibited titers above the positive cutoff for IgA and 94% were above cutoff for sAb. Fifty percent of participants exhibited less than a 2-fold reduction of Spike-specific IgA through 12 months. A strong significant positive correlation between IgA and sAb against Spike persisted throughout the study period. Nucleocapsid-specific Abs were also assessed, which revealed significant background or cross reactivity of milk IgA against this immunogen, as well as limited/inconsistent durability compared to Spike titers. These data suggests that lactating individuals are likely to continue producing Spike-specific Abs in their milk for 1 year or more, which may provide critical passive immunity to infants against SARS-CoV-2 throughout the lactation period.

Anti-SARS-CoV-2 Immunoglobulins in Human Milk after Coronavirus Disease or Vaccination-Time Frame and Duration of Detection in Human Milk and Factors That Affect Their Titers: A Systematic Review

Human milk (HM) of mothers infected with or vaccinated against SARS-CoV-2 contains specific immunoglobulins, which may protect their offspring against infection or severe disease. The time frame and duration after infection or vaccination, during which these immunoglobulins are detected in HM, as well as the major factors that influence their levels, have not been fully elucidated. This systematic review aimed to collect the existing literature and describe the immune response, specifically regarding the immunoglobulins in HM after COVID-19 disease or vaccination in non-immune women. We conducted a systematic search of PubMed and Scopus databases to identify studies published up until 19 March 2023. In total, 975 articles were screened, and out of which 75 were identified as being relevant and were finally included in this review. Infection by SARS-CoV-2 virus primarily induces an IgA immune response in HM, while vaccination predominantly elevates IgG levels. These immunoglobulins give HM a neutralizing capacity against SARS-CoV-2, highlighting the importance of breastfeeding during the pandemic. The mode of immune acquisition (infection or vaccination) and immunoglobulin levels in maternal serum are factors that seem to influence immunoglobulin levels in HM. Further studies are required to determine the impact of other factors, such as infection severity, lactation period, parity, maternal age and BMI on immunoglobulin level in HM.

Detection of IgA and IgG Antibodies against the Structural Proteins of SARS-CoV-2 in Breast Milk and Serum Samples Derived from Breastfeeding Mothers

Background: COVID-19 vaccination or natural infection is associated with the development of immunity. The search of IgA and IgG antibodies against all the structural proteins (spike, nucleocapsid, membrane, and envelope) of SARS-CoV-2 in breastfeeding mothers is associated with immunity that can help the newborn avoid development of the infection. Methods: In this study, we analyzed 30 breastfeeding women that provided samples of breast milk and serum and evaluated the presence of IgA, total IgG, and subclasses against the structural proteins of SARS-CoV-2. Results: We reported a high seroprevalence to IgA (76.67-100%) and negativity to IgG against all analyzed proteins in breast milk. Seroprevalence in serum samples was around 10-36.67% to IgA and 23.3-60% to IgG. Finally, we detected the presence of the subclasses IgG1, IgG2, and IgG4 against all the structural proteins of SARS-CoV-2. Conclusions: This work provides evidence of the presence of IgA and IgG antibodies against the four structural proteins of SARS-CoV-2 in breast milk and serum samples derived from breastfeeding women, which can confer immunity to the newborn.

Women's experiences and views on early breastfeeding during the COVID-19 pandemic in Norway: quantitative and qualitative findings from the IMAgiNE EURO study

BACKGROUND

Little is known about women's experience of care and views on early breastfeeding during the COVID-19 pandemic in Norway.

METHODS

Women (n = 2922) who gave birth in a facility in Norway between March 2020 and June 2021 were invited to answer an online questionnaire based on World Health Organization (WHO) Standard-based quality measures, exploring their experiences of care and views on early breastfeeding during the COVID-19 pandemic. To examine associations between year of birth (2020, 2021) and early breastfeeding-related factors, we estimated odds ratios (ORs) with 95% confidence intervals (CIs) using multiple logistic regression. Qualitative data were analysed using Systematic Text Condensation.

RESULTS

Compared to the first year of the pandemic (2020), women who gave birth in 2021 reported higher odds of experiencing adequate breastfeeding support (adjOR 1.79; 95% CI 1.35, 2.38), immediate attention from healthcare providers when needed (adjOR 1.89; 95% CI 1.49, 2.39), clear communication from healthcare providers (adjOR 1.76; 95% CI 1.39, 2.22), being allowed companion of choice (adjOR 1.47; 95% CI 1.21, 1.79), adequate visiting hours for partner (adjOR 1.35; 95% CI 1.09, 1.68), adequate number of healthcare providers (adjOR 1.24; 95% CI 1.02, 1.52), and adequate professionalism of the healthcare providers (adjOR 1.65; 95% CI 1.32, 2.08). Compared to 2020, in 2021 we found no difference in skin-to-skin contact, early breastfeeding, exclusive breastfeeding at discharge, adequate number of women per room, or women's satisfaction. In their comments, women described understaffed postnatal wards, early discharge and highlighted the importance of breastfeeding support, and concerns about long-term consequences such as postpartum depression.

CONCLUSIONS

In the second year of the pandemic, WHO Standard-based quality measures related to breastfeeding improved for women giving birth in Norway compared to the first year of the pandemic. Women's general satisfaction with care during COVID-19 did however not improve significantly from 2020 to 2021. Compared to pre-pandemic data, our findings suggest an initial decrease in exclusive breastfeeding at discharge during the COVID-19 pandemic in Norway with little difference comparing 2020 versus 2021. Our findings should alert researchers, policy makers and clinicians in postnatal care services to improve future practices.

Increase in SARS-CoV-2 RBD-Specific IgA and IgG Antibodies in Human Milk From Lactating Women Following the COVID-19 Booster Vaccination

BACKGROUND

The United States Centers for Disease Control and Prevention recommended a third dose or booster of the Pfizer-BioNTech Comirnaty (BNT162b2) COVID-19 mRNA vaccine in September 2021 for high-risk individuals. Pregnant and high-risk lactating women were encouraged to receive the booster to obtain potential prolonged protection for themselves and their infants.

RESEARCH AIM

To investigate the ability of the booster vaccine to increase IgA and IgG antibodies specific to the receptor-binding domain of the SARS-CoV-2 spike protein in human milk compared to levels pre-booster.

METHODS

This was a prospective one-group study with a pretest-posttest design. Six of 12 participants were recruited prospectively. Participants were instructed to collect ≥ 2 ounces of milk in the morning at 30 days and 1-day pre-booster, and 7, 14, 21, 30, 45, and 60 days post-booster. Levels of IgA and IgG antibodies specific to the receptor-binding domain of the SARS-CoV-2 spike protein were quantified in human milk via an ELISA assay.

RESULTS

We found a significant increase in anti-receptor-binding domain-specific IgA and IgG antibodies in human milk 1-2 weeks after the Pfizer-BioNTech booster and at the study endpoint (45- and 60-days post-booster).

CONCLUSIONS

This suggests that the booster vaccination enhances SARS-CoV-2 specific immunity in human milk, which may be protective for infants.

A Live Attenuated COVID-19 Candidate Vaccine for Children: Protection against SARS-CoV-2 Challenge in Hamsters

Children are at risk of infection from severe acute respiratory syndrome coronavirus-2 virus (SARS-CoV-2) resulting in coronavirus disease (COVID-19) and its more severe forms. New-born infants are expected to receive short-term protection from passively transferred maternal antibodies from their mothers who are immunized with first-generation COVID-19 vaccines. Passively transferred antibodies are expected to wane within first 6 months of infant's life, leaving them vulnerable to COVID-19. Live attenuated vaccines, unlike inactivated or viral-protein-based vaccines, offer broader immune engagement. Given effectiveness of live attenuated vaccines in controlling infectious diseases such as mumps, measles and rubella, we undertook development of a live attenuated COVID-19 vaccine with an aim to vaccinate children beyond 6 months of age. An attenuated vaccine candidate (dCoV), engineered to express sub-optimal codons and deleted polybasic furin cleavage sites in the spike protein of the SARS-CoV-2 WA/1 strain, was developed and tested in hamsters. Hamsters immunized with dCoV via intranasal or intramuscular routes induced high levels of neutralizing antibodies and exhibited complete protection against the SARS-CoV-2 wild-type isolates, i.e., the Wuhan-like (USA-WA1/2020) and Delta variants (B.1.617.2) in a challenge study. In addition, the dCoV formulated with the marketed measles-rubella (MR) vaccine, designated as MR-dCoV, administered to hamsters via intramuscular route, also protected against both SARS-CoV-2 challenges, and dCoV did not interfere with the MR vaccine-mediated immune response. The safety and efficacy of the dCoV and the MR-dCoV against both variants of SARS-CoV-2 opens the possibility of early immunization in children without an additional injection.

First do no harm overlooked: Analysis of COVID-19 clinical guidance for maternal and newborn care from 101 countries shows breastfeeding widely undermined

Background

In March 2020, the World Health Organization (WHO) published clinical guidance for the care of newborns of mothers with COVID-19. Weighing the available evidence on SARS-CoV-2 infection against the well-established harms of maternal-infant separation, the WHO recommended maternal-infant proximity and breastfeeding even in the presence of maternal infection. Since then, the WHO's approach has been validated by further research. However, early in the pandemic there was poor global alignment with the WHO recommendations.

Methods

We assessed guidance documents collected in November and December 2020 from 101 countries and two regional agencies on the care of newborns of mothers with COVID-19 for alignment with the WHO recommendations. Recommendations considered were: (1) skin-to-skin contact; (2) early initiation of breastfeeding; (3) rooming-in; (4) direct breastfeeding; (5) provision of expressed breastmilk; (6) provision of donor human milk; (7) wet nursing; (8) provision of breastmilk substitutes; (9) relactation; (10) psychological support for separated mothers; and (11) psychological support for separated infants.

Results

In less than one-quarter of country guidance were the three key breastfeeding facilitation practices of skin-to-skin contact, rooming-in, and direct breastfeeding recommended. Donor human milk was recommended in under one-quarter of guidance. Psychological support for mothers separated from their infants was recommended in 38%. Few countries recommended relactation, wet nursing, or psychological support for infants separated from mothers. In three-quarters of country guidance, expressed breastmilk for infants unable to directly breastfeed was recommended. The WHO and the United Kingdom's Royal College of Obstetricians and Gynecologists were each cited by half of country guidance documents with the United States Centers for Disease Control and Prevention directly or indirectly cited by 40%.

Conclusion

Despite the WHO recommendations, many COVID-19 maternal and newborn care guidelines failed to recommend skin-to-skin contact, rooming-in, and breastfeeding as the standard of care. Irregular guidance updates and the discordant, but influential, guidance from the United States Centers for Disease Control may have been contributory. It appeared that once recommendations were made for separation or against breastfeeding they were difficult to reverse. In the absence of quality evidence on necessity, recommendations against breastfeeding should not be made in disease epidemics.

Can COVID-19 Vaccines Induce Premature Non-Communicable Diseases: Where Are We Heading to?

According to the WHO, as of January 2023, more than 850 million cases and over 6.6 million deaths from COVID-19 have been reported worldwide. Currently, the death rate has been reduced due to the decreased pathogenicity of new SARS-CoV-2 variants, but the major factor in the reduced death rates is the administration of more than 12.8 billion vaccine doses globally. While the COVID-19 vaccines are saving lives, serious side effects have been reported after vaccinations for several premature non-communicable diseases (NCDs). However, the reported adverse events are low in number. The scientific community must investigate the entire spectrum of COVID-19-vaccine-induced complications so that necessary safety measures can be taken, and current vaccines can be re-engineered to avoid or minimize their side effects. We describe in depth severe adverse events for premature metabolic, mental, and neurological disorders; cardiovascular, renal, and autoimmune diseases, and reproductive health issues detected after COVID-19 vaccinations and whether these are causal or incidental. In any case, it has become clear that the benefits of vaccinations outweigh the risks by a large margin. However, pre-existing conditions in vaccinated individuals need to be taken into account in the prevention and treatment of adverse events.

The impact on colostrum oxidative stress, cytokines, and immune cells composition after SARS-CoV-2 infection during pregnancy

Background

Limited data are available regarding the differences between immunological, biochemical, and cellular contents of human colostrum following maternal infection during pregnancy with coronavirus 2 disease (COVID-19).

Objective

To investigate whether maternal COVID-19 infection may affect immunological, biochemical, and cellular contents of human colostrum.

Methods

Using a case-control study design, we collected colostrum from 14 lactating women with a previous diagnosis of COVID-19 during pregnancy and 12 without a clear diagnosis during September 2020 to May 2021. Colostrum samples were analysed for some enzymes and non-enzymatic oxidative stress markers (SOD, CAT, GPx, MDA, GSH, GSSG, H2O2, MPO) and for IL-1β, IL-6, tumour necrosis factor (TNF)-α, protein induced by interferon gamma (IP)-10, IL-8, IFN-λ1, IL12p70, IFN-α2, IFN-λ2/3, granulocyte macrophage colony stimulating factor (GM-CSF), IFN-β, IL-10 and IFN-γ, along with IgA and IgG for the SARS-CoV-2 S protein. We perform immunophenotyping to assess the frequency of different cell types in the colostrum.

Results

Colostrum from the COVID-19 symptomatic group in pregnancy contained reduced levels of H2O2, IFN-α2, and GM-CSF. This group had higher levels of GSH, and both NK cell subtypes CD3-CD56brightCD16-CD27+IFN-γ+ and CD3-CD56dimCD16+CD27- were also increased.

Conclusion

The present results reinforce the protective role of colostrum even in the case of mild SARS-Cov-2 infection, in addition to demonstrating how adaptive the composition of colostrum is after infections. It also supports the recommendation to encourage lactating women to continue breastfeeding after COVID-19 illness.

The Gut Microbiome of Children during the COVID-19 Pandemic

The gut microbiome has been shown to play a critical role in maintaining a healthy state. Dysbiosis of the gut microbiome is involved in modulating disease severity and potentially contributes to long-term outcomes in adults with COVID-19. Due to children having a significantly lower risk of severe illness and limited sample availability, much less is known about the role of the gut microbiome in children with COVID-19. It is well recognized that the developing gut microbiome of children differs from that of adults, but it is unclear if this difference contributes to the different clinical presentations and complications. In this review, we discuss the current knowledge of the gut microbiome in children with COVID-19, with gut microbiome dysbiosis being found in pediatric COVID-19 but specific taxa change often differing from those described in adults. Additionally, we discuss possible mechanisms of how the gut microbiome may mediate the presentation and complications of COVID-19 in children and the potential role for microbial therapeutics.

Factors associated with exclusive breastfeeding at discharge during the COVID-19 pandemic in 17 WHO European Region countries

BACKGROUND

Exclusive breastfeeding is the optimal infant nutrition, providing infants immunoprotection against many diseases including SARS-CoV-2 infection. Restrictions during the COVID-19 pandemic may have negatively affected breastfeeding practices in maternity care facilities. The aims of the study were to examine exclusive breastfeeding rates at discharge over time and to identify factors associated with exclusive breastfeeding during the pandemic.

METHODS

A cross-sectional survey was conducted among mothers who gave birth in a maternity care facility in the World Health Organization (WHO) European Region countries during the COVID-19 pandemic. The socio-ecological model was employed to examine intrapersonal, interpersonal, organizational, and community/society factors associated with maternal report of exclusive breastfeeding at the time of discharge.

RESULTS

There were 26,709 participating mothers from 17 European Region countries who were included in the analysis. Among the mothers, 72.4% (n = 19,350) exclusively breastfed and 27.6% (n = 7,359) did not exclusively breastfeed at discharge. There was an overall decline in exclusive breastfeeding rates over time (p = 0.015) with a significantly lower rate following the publication of the WHO breastfeeding guidelines on 23 June 2020 (AOR 0.88; 95% CI 0.82, 0.94). Factors significantly associated with exclusive breastfeeding outcomes in the logistic regression analysis included maternal age, parity, education, health insurance, mode of birth, inadequate breastfeeding support, lack of early breastfeeding initiation, lack of full rooming-in, birth attendant, perceived healthcare professionalism and attention, facility room cleanliness, timing of birth, and location of birth.

CONCLUSIONS

Results from the study indicate the decline in exclusive breastfeeding rates in the WHO European Region during the COVID-19 pandemic. Using the socio-ecological model to identify factors associated with breastfeeding outcomes facilitates an integrated and holistic approach to address breastfeeding needs among women across the region. These findings demonstrate the need to augment breastfeeding support and to protect exclusive breastfeeding among mother-infant dyads, in an effort to reverse the declining exclusive breastfeeding rates. The study highlights the need to educate mothers and their families about the importance of exclusive breastfeeding, reduce maternal-infant separation, increase professional breastfeeding support, and follow evidence-based practice guidelines to promote breastfeeding in a comprehensive and multi-level manner.

TRIAL REGISTRATION NUMBER

Clinical Trials NCT04847336.

Mother to Newborn Transmission of SARS-CoV-2 Infection: Evolution of Evidence in 1.5 Years of COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) pandemic caused significant mortality and morbidity in people of all age groups worldwide. Given the uncertainty regarding the mode of transmission and potential effects of COVID-19 on pregnant mothers and their newborns, guidelines for taking care of maternal-newborn dyads have evolved tremendously since the pandemic began. There has been an enormous influx of published materials regarding the outcomes of mothers and newborns. Still, multiple knowledge gaps regarding comprehensive information about risk to the mothers and newborns exist, which need to be addressed. Current evidence suggests that mothers with symptomatic COVID-19 infection are at increased risk of severe illness during pregnancy, with a higher need for respiratory support and premature deliveries. Neonates born to mothers with COVID-19 are at increased risk of needing intensive care; however, most newborns do well after birth. As new mutant variants arise, we need to be cautious while proactively understanding any new evolving patterns. All leading health authorities strongly recommend COVID-19 vaccination before or during pregnancy to reduce the risk of maternal morbidities and benefit from passing antibodies to newborns prenatally and via breastmilk. Additionally, there are racial, ethnic, and socioeconomic disparities in outcomes and vaccination coverage for pregnant women. This article summarizes the rapidly evolving evidence for the last 1.5 years and aims to help health care professionals care for mothers with COVID-19 and their newborns. KEY POINTS: · COVID-19 in pregnancy can cause perinatal morbidities.. · Breastfeeding and breast milk are safe for newborns.. · COVID-19 vaccination reduces the risk for morbidities..

Characterization of SARS-CoV-2 antibodies in human milk from 21 women with confirmed COVID-19 infection

BACKGROUND

One potential mechanism for protection from SARS-CoV-2 in children is through passive immunity via breast milk from a mother infected with the novel coronavirus. The primary objectives of this study were to establish the presence of SARS-CoV-2-specific IgA and IgG and to characterize the antigenic regions of SARS-CoV-2 proteins that were reactive with antibodies in breast milk.

METHODS

Between March 2020 and September 2020, 21 women with confirmed SARS-CoV-2 infection were enrolled in Mommy's Milk. Participants donated serial breast milk samples around their time of illness. Breast milk samples were used to probe a multi-coronavirus protein microarray containing full-length and variable-length overlapping fragments of SARS-CoV-2 proteins. Samples were also tested against S and N proteins by electrochemiluminescence assay.

RESULTS

The breast milk samples contained IgA reactive with a variety of SARS-CoV-2 antigens. The most IgA-reactive SARS-CoV-2 proteins were N (42.9% of women responded to ≥1 N fragment) and S proteins (23.9% responded to ≥1 fragment of S1 or S2). IgG responses were similar. A striking observation was the dissimilarity between mothers in antibody recognition, giving distinct antibody reactivity and kinetic profiles.

CONCLUSIONS

Individual COVID-19 cases had diverse and unique milk IgA profiles following the onset of symptoms.

IMPACT

In this observational longitudinal case series of 21 women with confirmed SARS-CoV-2 infection, IgA binding to SARS-CoV-2 proteins detected by orthologous proteome microarray and electrochemiluminescence assays was observed in >75% of women, but there was heterogeneity in which antigens and how many were reactive between women. Immunological profiles of protein regions recognized by each woman were distinct. Diverse repertoires of mucosal breast milk antibody to SARS-CoV-2 reflect heterogeneous passive transfer of maternal antibody to exposed breastfeeding infants.

Cytokines and Chemokines in Breastmilk of SARS-CoV-2 Infected or COVID-19 Vaccinated Mothers

INTRODUCTION

The COVID-19 disease and anti-SARS-CoV-2 vaccination were accompanied by alterations in several inflammatory markers. The aim of our research was to check to what extent such cytokines are transferred to infants via the breastmilk of SARS-CoV-2-infected or vaccinated mothers. Thus, we wanted to check if breastfeeding is safe during SARS-CoV-2 infection or after COVID-19 mRNA-vaccination.

MATERIAL AND METHOD

The Luminex Multiplexing Assay was used for quantifying 10 cytokine in the human breastmilk of SARS-CoV-2-infected or COVID-19-vaccinated mothers, compared with anti-SARS-CoV-2 IgG naïve mothers. Two milk samples were collected at 30 and 60 days either after the booster dose or afterthe onset of symptoms. A single milk sample was collected from the mothers within the control group.

RESULTS

The cytokine concentrations were mostly found within the reference intervals for all mothers. The status of the vaccinated/infected mother, the age of the breastfed child, the parity of the mother and the maternal age were variation factors of the above-mentioned cytokine concentrations. The type of birth and the presence of IgG in the milk had no influence on these cytokine concentrations in milk. Furthermore, no statistically significant differences were recorded between the cytokine concentrations of the two milk samples.

CONCLUSION

Our study provides data that support the safety of breastfeeding in the case of mild COVID-19 infection or after Pfizer or Moderna vaccinations.

Sodium and Potassium Concentrations and Somatic Cell Count of Human Milk Produced in the First Six Weeks Postpartum and Their Suitability as Biomarkers of Clinical and Subclinical Mastitis

The sodium (Na) concentration and the ratio of Na to potassium (K; Na/K) in human milk are used commonly as biomarkers of subclinical mastitis, but limited data exist on their relationship to and ability to predict clinical mastitis. Here, we assessed concentrations of Na, K, Na/K, and somatic cell count (SCC), a mammary health biomarker used in the dairy industry, in milk prospectively collected from both breasts of 41 women over the first 6 weeks postpartum. Although values differed over time postpartum, there were no differences in mean values between breasts. Nearly one-quarter (24%) of participants experienced clinical mastitis. Somatic cell counts >4.76 × 105 cells/mL were most strongly related to development of clinical mastitis in the following week (odds ratio, 7.81; 95% CI, 2.15−28.30; p = 0.002), although relationships were also observed for SCC > 4.00 × 105 cells/mL and Na concentration >12 mmol/L. Estimates of the prevalence of subclinical mastitis in women who never progressed to clinical mastitis differed by biomarker but ranged from 20 to 75%. Despite these findings, positive predictive values (PPV) of the biomarkers for identifying clinical mastitis were low (≤0.34), indicating additional research is needed to identify single biomarkers or composite measures that are highly specific, sensitive, and predictive of clinical mastitis in women.

Dynamics of SARS-CoV-2 exposure in Malawian infants between February 2020 and May 2021

Background

Very limited information is available on SARS-CoV-2 seroprevalence in infants in sub-Saharan countries.

Objective

In this study, we aimed to determine the rate and the temporal evolution of SARS CoV-2 seropositivity in breastfed Malawian infants.

Study design

Blood samples (n = 250) from 158 infants, born to HIV-negative women and women living with HIV, collected from February 2020 to May 2021, were first tested using an Anti-IgG/A/M SARS CoV 2 ELISA assay against trimeric spike protein, and then, if positive, confirmed using a second ELISA assay detecting IgG against Receptor Binding Domain.

Results

The confirmed prevalence of anti-SARS CoV-2 antibodies was 31.0% (95% CI: 23.7%-38.3%) with no significant difference between HIV-exposed and HIV-unexposed infants (29.3% and 37.1% respectively, P = 0.410). The presence of anti-SARS-CoV-2 IgG was not associated with maternal socioeconomic or demographic indices.

Conclusions

Our data underline the wide spread of the SARS-CoV-2 infection in the pediatric population in sub-Saharan Africa. Design of more specific serological tests for African samples and improvements in serosurveillance programs are needed for more rigorous monitoring of the dynamics of SARS-CoV-2 infection in Africa.

Role of the humoral immune response during COVID-19: guilty or not guilty?

Systemic and mucosal humoral immune responses are crucial to fight respiratory viral infections in the current pandemic of COVID-19 caused by the SARS-CoV-2 virus. During SARS-CoV-2 infection, the dynamics of systemic and mucosal antibody infections are affected by patient characteristics, such as age, sex, disease severity, or prior immunity to other human coronaviruses. Patients suffering from severe disease develop higher levels of anti-SARS-CoV-2 antibodies in serum and mucosal tissues than those with mild disease, and these antibodies are detectable for up to a year after symptom onset. In hospitalized patients, the aberrant glycosylation of anti-SARS-CoV-2 antibodies enhances inflammation-associated antibody Fc-dependent effector functions, thereby contributing to COVID-19 pathophysiology. Current vaccines elicit robust humoral immune responses, principally in the blood. However, they are less effective against new viral variants, such as Delta and Omicron. This review provides an overview of current knowledge about the humoral immune response to SARS-CoV-2, with a particular focus on the protective and pathological role of humoral immunity in COVID-19 severity. We also discuss the humoral immune response elicited by COVID-19 vaccination and protection against emerging viral variants.

SARS-CoV-2 specific antibody trajectories in mothers and infants over two months following maternal infection

Infants exposed to caregivers infected with SARS-CoV-2 may have heightened infection risks relative to older children due to their more intensive care and feeding needs. However, there has been limited research on COVID-19 outcomes in exposed infants beyond the neonatal period. Between June 2020 - March 2021, we conducted interviews and collected capillary dried blood spots from 46 SARS-CoV-2 infected mothers and their infants (aged 1-36 months) for up to two months following maternal infection onset (COVID+ group, 87% breastfeeding). Comparative data were also collected from 26 breastfeeding mothers with no known SARS-CoV-2 infection or exposures (breastfeeding control group), and 11 mothers who tested SARS-CoV-2 negative after experiencing symptoms or close contact exposure (COVID- group, 73% breastfeeding). Dried blood spots were assayed for anti-SARS-CoV-2 S-RBD IgG and IgA positivity and anti-SARS-CoV-2 S1 + S2 IgG concentrations. Within the COVID+ group, the mean probability of seropositivity among infant samples was lower than that of corresponding maternal samples (0.54 and 0.87, respectively, for IgG; 0.33 and 0.85, respectively, for IgA), with likelihood of infant infection positively associated with the number of maternal symptoms and other household infections reported. COVID+ mothers reported a lower incidence of COVID-19 symptoms among their infants as compared to themselves and other household adults, and infants had similar PCR positivity rates as other household children. No samples returned by COVID- mothers or their infants tested antibody positive. Among the breastfeeding control group, 44% of mothers but none of their infants tested antibody positive in at least one sample. Results support previous research demonstrating minimal risks to infants following maternal COVID-19 infection, including for breastfeeding infants.

SARS-CoV-2-Specific IgG and IgA response in maternal blood and breastmilk of vaccinated naïve and convalescent lactating participants

Background

Recent studies have shown the presence of SARS-CoV-2-specific antibodies in the milk of breastfeeding mothers vaccinated with mRNA and convalescent. However, limited information is available in lactating women receiving other vaccine platforms used in developing countries, such as the inactivated SARS-CoV-2 vaccine BBIBP-CorV (Sinopharm) and the non-replicating adenovirus vaccines Sputnik V (Gamaleya Institute) and ChAdOx1-S (Oxford AstraZeneca).

Methods

Here, we evaluated anti-SARS-CoV-2 IgG and IgA levels in both serum and milk samples using a longitudinal and a cross-sectional cohort of 208 breastfeeding vaccinated women from Argentina with or without previous SARS-CoV-2 infection.

Results

The analysis showed that IgA levels remain constant in serum and milk of breastfeeding mothers between the first and second doses of vector-based vaccines (Sputnik V and ChAdOx1-S). After the second dose, anti-spike IgA was found positive in 100% of the serum samples and in 66% of breastmilk samples. In addition, no significant differences in milk IgA levels were observed in participants receiving BBIBP-CorV, Sputnik V or ChAdOx1-S. IgG levels in milk increased after the second dose of vector-based vaccines. Paired longitudinal samples taken at 45 and 120 days after the second dose showed a decrease in milk IgG levels over time. Study of IgA levels in serum and milk of vaccinated naïve of infection and vaccinated-convalescent breastfeeding participants showed significantly higher levels in vaccinated-convalescent than in participants without previous infection.

Conclusion

This study is relevant to understand the protection against SARS-CoV-2 by passive immunity in newborns and children who are not yet eligible to receive vaccination.

No infectious SARS-CoV-2 in breast milk from a cohort of 110 lactating women

BACKGROUND

Genomic RNA of severe acute respiratory syndrome-associated coronavirus type 2 (SARS-CoV-2) has been detected in the breast milk of lactating women, but its pathological significance has remained uncertain due to the small size of prior studies.

METHODS

Breast milk from 110 lactating women was analyzed by reverse transcription-polymerase chain reaction (285 samples) and viral culture (160 samples). Those containing SARS-CoV-2 viral RNA (vRNA) were examined for the presence of subgenomic RNA (sgRNA), a putative marker of infectivity.

RESULTS

Sixty-five women had a positive SARS-CoV-2 diagnostic test, 9 had symptoms but negative diagnostic tests, and 36 symptomatic women were not tested. SARS-CoV-2 vRNA was detected in the milk of 7 (6%) women with either a confirmed infection or symptomatic illness, including 6 of 65 (9%) women with a positive SARS-CoV-2 diagnostic test. Infectious virus was not detected in any culture and none had detectable sgRNA. In control experiments, infectious SARS-CoV-2 could be cultured after addition to breastmilk despite several freeze-thaw cycles, as it occurs in the storage and usage of human milk.

CONCLUSIONS

SARS-CoV-2 RNA can be found infrequently in the breastmilk after recent infection, but we found no evidence that breastmilk contains an infectious virus or that breastfeeding represents a risk factor for transmission of infection to infants.

IMPACT

This article goes beyond prior small studies to provide evidence that infectious SARS-CoV-2 is not present in the milk of lactating women with recent infection, even when SARS-CoV-2 RNA is detected. Recent SARS-CoV-2 infection or detection of its RNA in human milk is not a contraindication to breastfeeding.