SARS-CoV-2 RNA and antibody detection in breast milk from a prospective multicentre study in Spain

This study has been supported by a research grant from Fundacion La Marato-TV3 (MilkCORONA, ref 202106).Objectives To develop and validate a specific protocol for SARS-CoV- 2 detection in breast milk matrix and to determine the impact of maternal SARS-CoV- 2 infection on the presence, concentration and persistence of specific SARS-CoV- 2 antibodies. Design and patients This is a prospective, multicentre longitudinal study (April–December 2020) in 60 mothers with SARS-CoV- 2 infection and/or who have recovered from COVID-19. A control group of 13 women before the pandemic were also included. Setting Seven health centres from different provinces in Spain. Main outcome measures Presence of SARS-CoV- 2 RNA in breast milk, targeting the N1 region of the nucleocapsid gene and the envelope (E) gene; presence and levels of SARS-CoV- 2-specific immunoglobulins (Igs)—IgA, IgG and IgM—in breast milk samples from patients with COVID-19. Results All breast milk samples showed negative results for presence of SARS-CoV- 2 RNA. We observed high intraindividual and interindividual variability in the antibody response to the receptor-binding domain of the SARS-CoV- 2 spike protein for each of the three isotypes IgA, IgM and IgG. Main Protease (MPro) domain antibodies were also detected in milk. 82.9% (58 of 70) of milk samples were positive for at least one of the three antibody isotypes, with 52.9% of these positive for all three Igs. Positivity rate for IgA was relatively stable over time (65.2%–87.5%), whereas it raised continuously for IgG (from 47.8% for the first 10 days to 87.5% from day 41 up to day 206 post-PCR confirmation). Conclusions Our study confirms the safety of breast feeding and highlights the relevance of virus-specific SARS-CoV- 2 antibody transfer. This study provides crucial data to support official breastfeeding recommendations based on scientific evidence.Fundacion La Marato-TV3 20210

SARS-CoV-2 RNA and antibody detection in human milk from a prospective multicenter study in Spain

Objectives To develop and validate a specific protocol for SARS-CoV-2 detection in breast milk matrix and to determine the impact of maternal SARS-CoV-2 infection on the presence, concentration and persistence of specific SARS-CoV-2 antibodies. Design and patients This is a prospective, multicentre longitudinal study (April-December 2020) in 60 mothers with SARS-CoV-2 infection and/or who have recovered from COVID-19. A control group of 13 women before the pandemic were also included. Setting Seven health centres from different provinces in Spain. Main outcome measures Presence of SARS-CoV-2 RNA in breast milk, targeting the N1 region of the nucleocapsid gene and the envelope (E) gene; presence and levels of SARS-CoV-2-specific immunoglobulins (Igs)¿IgA, IgG and IgM¿in breast milk samples from patients with COVID-19. Results All breast milk samples showed negative results for presence of SARS-CoV-2 RNA. We observed high intraindividual and interindividual variability in the antibody response to the receptor-binding domain of the SARS-CoV-2 spike protein for each of the three isotypes IgA, IgM and IgG. Main Protease (MPro) domain antibodies were also detected in milk. 82.9% (58 of 70) of milk samples were positive for at least one of the three antibody isotypes, with 52.9% of these positive for all three Igs. Positivity rate for IgA was relatively stable over time (65.2%-87.5%), whereas it raised continuously for IgG (from 47.8% for the first 10 days to 87.5% from day 41 up to day 206 post-PCR confirmation). Conclusions Our study confirms the safety of breast feeding and highlights the relevance of virus-specific SARS-CoV-2 antibody transfer. This study provides crucial data to support official breastfeeding recommendations based on scientific evidence

Breastfeeding during the COVID-19 pandemic: analysis of the breastmilk antibodies, neutralization capacity and microbiota profile from infected and vaccinated wome

Resumen del póster presentado a las III Jornadas Científicas PTI+ Salud Global, celebradas en el Centro de Ciencias Humanas y Sociales (CCHS), CSIC (Madrid) del 20 al 22 de noviembre de 2023.[Background] Breastmilk is considered the gold standard in infant nutrition and provides bioactive compounds to the neonate, among them antibodies and microbiota. In the context of the COVID- 19 pandemics, there were great concerns about a possible mother-to-infant transfer of SARS-CoV-2, since limited knowledge about the safety of breastfeeding after natural infection or vaccination, as well as the transfer of protective antibodies and their neutralization capacity, was available. Additionally, there are concerns about potential short- and long-term adverse effects of SARS-CoV-2 infection and vaccine-induced changes to the breastmilk microbiome composition, which contributes in shaping the early-life microbiome.[Methods] This study included 60 mothers which had a confirmed SARS-CoV-2 infection and also, 86 mothers vaccinated with mRNA-based (Comirnaty, mRNA-1273) and adenoviral-vectored vaccines (ChAdOx1 nCoV-19) were recruited and breastmilk samples were collected longitudinally from baseline up to 30 days after the second dose at seven or eight time points (depending on vaccine type). In COVID-19 lactating mothers, the presence of SARS-CoV-2 was assessed by RT-qPCR targeting the N1 region of the nucleocapsid gene and the envelope (E) gene. In both studies, the levels of SARS-CoV-2 RBD-specific IgA, IgM and IgG were determined by ELISA. The neutralization capacity was tested using pseudotyped vesicular stomatitis virus carrying either the Wuhan-Hu-1, Delta, or BA.1 Omicron spike proteins. To assess the microbiome composition, DNA from breastmilk samples was extracted and the V3-V4 region of the 16S rRNA gene was sequenced using the MiSeq system of Illumina.[Results] After SARS-CoV-2 infection, no virus-specific RNA was detected in breastmilk samples. Determination of antibody levels in mothers with confirmed SARS-CoV-2 infection showed that 82.9% (58 of 70) of milk samples were positive for at least one of the three tested antibody isotypes. Vaccination elicited also a strong induction of SARS-CoV-2-specific antibodies, which was higher in IgG when compared to COVID-19 convalescent women and was strongly increased after the 2nd dose. mRNA-based vaccines induced higher IgG and IgA levels when compared to the adenovirus- vectored vaccine, and women with previous virus exposure increased their IgG antibodies levels after the first dose to a similar level observed in vaccinated women after the second dose. When assessing the neutralization capacity, natural infection resulted in higher neutralizing titers that correlated positively with levels of SARS-CoV-2-specific immunoglobulin A in breastmilk. Breastmilk samples from COVID-19 convalescent mothers infected during the first wave (Wuhan-Hu-1 strain) neutralized less effectively Omicron BA.1 than the Wuhan-Hu-1 variant. 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. First results of the analysis of the breastmilk microbiome found no significant differences in the mean diversity of species (alpha-diversity) after natural SARS-CoV-2 infection, whereas some specific bacterial groups were increased (e.g. Enterobacteriaceae).[Conclusions] Overall, our results indicate that breastmilk from naturally infected women or those vaccinated with mRNA-based vaccines contain SARS-CoV-2 neutralizing antibodies that could potentially provide protection to breastfed infants from infection.Peer reviewe

Metallomic and Untargeted Metabolomic Signatures of Human Milk from SARS-CoV-2 Positive Mothers

Scope: Lack of information about the impact of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the elemental and metabolomic profile of human milk (HM). Methods and results: An observational study on HM from mothers with COVID-19 is conducted including a prepandemic control group. Maternal-infant clinical records and symptomatology are recorded. The absolute quantification of elements and untargeted relative metabolomic profiles are determined by inductively coupled plasma mass spectrometry and gas chromatography coupled to mass spectrometry, respectively. Associations of HM SARS-CoV-2 antibodies with elemental and metabolomic profiles are studied. COVID-19 has a significant impact on HM composition. COVID-19 reduces the concentrations of Fe, Cu, Se, Ni, V, and Aluminium (Al) and increases Zn compared to prepandemic control samples. A total of 18 individual metabolites including amino acids, peptides, fatty acids and conjugates, purines and derivatives, alcohols, and polyols are significantly different in HM from SARS-CoV-2 positive mothers. Aminoacyl-tRNA biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine, and linoleic acid pathways are significantly altered. Differences are obtained depending on COVID-19 symptomatic and asymptomatic status. Conclusions: This study provides unique insights about the impact of maternal SARS-CoV-2 infection on the elemental and metabolomic profiles of HM that warrants further research due the potential implications for infant health

SARS-CoV-2 RNA and antibody detection in human milk from a prospective multicenter study in Spain

Background During the COVID-19 pandemic in 2020, breastfeeding in women positive for SARS-CoV-2 was compromised due to contradictory data regarding potential viral transmission. However, growing evidence confirms the relevant role of breast milk in providing passive immunity by generating and transmitting specific antibodies against the virus. Thus, our study aimed to develop and validate a specific protocol to detect SARS-CoV-2 in breast milk matrix as well as to determine the impact of maternal SARS-CoV-2 infection on presence, concentration, and persistence of specific SARS-CoV-2 antibodies. Study design/Methods A prospective multicenter longitudinal study in Spain was carried out from April to December 2020. A total of 60 mothers with SARS-CoV-2 infection and/or recovered from COVID-19 were included (n=52 PCR-diagnosed and n=8 seropositive). Data from maternal-infant clinical records and symptomatology were collected. A specific protocol was validated to detect SARS-CoV-2 RNA in breast milk, targeting the N1 region of the nucleocapsid gene and the envelope (E) gene. Presence and levels of SARS-CoV-2 specific immunoglobulins (Igs) -IgA, IgG, and IgM-in breast milk samples from COVID-19 patients and from 13 women before the pandemic were also evaluated. Results All breast milk samples showed negative results for SARS-CoV-2 RNA presence. We observed high intra- and inter-individual variability in the antibody response to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein for each of the three isotypes IgA, IgM and IgG. Protease domain (MPro) antibodies were also detected in milk. In general, 82.9 % of the milk samples were positive for at least one of the three antibody isotypes, being 52.86 % of those positive for all three Igs. Positivity rate for IgA was relatively stable over time (65.2 – 87.5 %), whereas it raised continuously for IgG (47.8 % the first ten days to 87.5 % from day 41 up to day 206 post-PCR confirmation). Conclusions Considering the lack of evidence for SARS-CoV-2 transmission through breast milk, our study confirms the safety of breastfeeding practices and highlights the relevance of virus-specific SARS-CoV-2 antibody transfer, that would provide passive immunity to breastfed infants and protect them against COVID-19 disease. This study provides crucial data to support official breastfeeding recommendations based on scientific evidence.N