ABSTRACT
Breastfeeding rendered crucial for preterm infants during COVID-19 pandemic. However, the role of donated human milk (DHM) in the protection against SARS-CoV-2 infection when own mother’s milk is not available or insufficient remains unclear. Pasteurization of DHM contributes to the loss of some biological and nutritional properties of human milk. The presence of specific breast milk SARS-CoV-2 antibodies has been demonstrated in women after COVID-19 disease and after vaccination. We aimed to evaluate the impact of Holder pasteurization on vaccinated donor women’s milk and to identify the impact on the concentrations of specific immunoglobulins (Ig) against SARS-CoV-2. A prospective, observational, exploratory pilot study in lactating women (n=12) who received the complete course of mRNA-based vaccines (BioNTech/Pfizer) against SARS-CoV-2 infection was conducted. Levels of antibodies directed to structural receptor-binding domain of the SARS-CoV-2 spike protein were determined by ELISA before and after pasteurization.IgA and IgG anti-SARS-CoV-2 immunoglobulin concentrations were significantly reduced after Holder pasteurization. Interestingly, there was a negative correlation between the initial amount of anti-SARS-CoV-2 antibodies and the percentage of their recovery after the pasteurization for both isotypes. Despite the partial loss of immunoglobulins still a high percentage of antibodies remained after the pasteurization, a mean of 70.53 (3.4)% of anti-SARS-CoV-2 IgA and 81.99 (21.89)% of IgG antibodies. Our study underscores the potential relevance of breast feeding or alternatively DHM to provide babies at risk with virus-specific SARS-CoV-2 antibodies thus protecting them against COVID-19.
Subject(s)
COVID-19ABSTRACT
Background: We aimed to characterize the role of the nasopharyngeal microbiota in pregnant women with and without SARS-CoV-2 infection.Methods: Pregnant women were enrolled from a multicenter prospective population-based cohort (March-June 2020 in Barcelona, Spain) in which the status of SARS-CoV-2 infection was determined by nasopharyngeal RT–PCR and antibodies in peripheral blood. DNA was extracted from nasopharyngeal swab samples, and the V3-V4 region of the 16S rRNA of bacteria was amplified using region-specific primers. The differential abundance of taxa was tested, and alpha/beta diversity was evaluated.Results: Among 76 women, 38 were classified as positive and 38 as negative for SARS-CoV-2 infection. All positive women were diagnosed by antibodies, and 14 (37%) also had a positive RT–PCR. SARS-CoV-2 infection altered the overall composition of the nasopharyngeal microbiota (p=0.001), with a higher relative abundance of the Tenericutes and Bacteroidetes phyla and a higher abundance of the Prevotellaceae family. Infected women presented a different pattern of microbiota profiling due to beta diversity and higher richness (observed ASV<0.001) and evenness (Shannon index<0.001) at alpha diversity. These changes persisted after acute infection, as revealed by negative RT–PCR but positive antibodies, suggesting a long-lasting effect of SARS-CoV-2 in the nasopharyngeal microbiota. No significant differences were reported in mild vs. severe cases, suggesting a role of the SARS-CoV-2 infection itself but not on its severity.Conclusion: This is the first study on nasopharyngeal microbiota during pregnancy. SARS-CoV-2 infection altered the overall structure and diversity of the nasopharyngeal microbiota profile, and this effect seems to persist after the acute moment of the infection.
Subject(s)
COVID-19ABSTRACT
Structured AbstractO_ST_ABSImportanceC_ST_ABSLimited data are available on COVID-19 vaccine impact in lactating women. ObjectiveTo evaluate the impact of different COVID-19 vaccines on specific anti-SARS-CoV-2 IgA and IgG levels in human milk. Design, Settings and ParticipantsIn this prospective observational study in Spain, 75 lactating women from priority groups receiving vaccination against SARS-CoV-2 were included (January to April 2021). Human milk samples were collected at seven-time points. A group with confirmed SARS-CoV-2 infection (n=19) and a group of women from prepandemic time (n=13) were included. ExposuremRNA vaccines (BNT162b2 and mRNA-1273) and adenovirus-vectored vaccine (ChAdOx1 nCoV-19). Main Outcome(s) and Measure(s)Presence of IgA and IgG against RBD SARS-CoV-2 in breast milk. ResultsSeventy-five vaccinated lactating women [mean age, 34.9 {+/-} 3.7 years] of whom 96% were Caucasic and 92% were health care workers. A total of 417 milk samples were included and vaccine distribution was BioNTech/Pfizer (BNT162b2, n=30), Moderna (mRNA-1273, n=21), and AstraZeneca (ChAdOx1 nCoV-19, n=24). For each vaccine, 7 time points were collected from baseline up to 25 days after the 1st dose and same points were collected for mRNA vaccines 30 days after 2nd dose. A strong reactivity was observed for IgG and IgA after vaccination mainly after the 2nd dose. Presence and the persistence of specific SARS-CoV-2 antibodies in breast milk were dependent on the vaccine-type and, on previous virus exposure. High inter-variability was observed, being relevant for IgA antibodies. IgG levels were significantly higher than those observed in milk from COVID-19 women while IgA levels were lower. Women with previous COVID-19 increased the IgG levels after the 1st dose to a similar level observed in vaccinated women after the 2nd dose. Conclusions and RelevanceBreast milk from vaccinated women contains anti-SARS-CoV-2 IgA and IgG, with highest after the 2nd dose. Levels were dependent on vaccine type and previous exposure to SARS-CoV-2. Previous COVID-19 influenced the vaccine effect after a single dose, which could be especially relevant in the design of vaccination protocols. Further studies are warranted to demonstrate the potential protective role of these antibodies against COVID-19 in infants from vaccinated and infected mothers through breastfeeding. Trial RegistrationNCT04751734 Key PointsO_ST_ABSQuestionC_ST_ABSWhat is the effect of the different COVID-19 vaccines on the anti-SARS-CoV-2 antibodies in breast milk? Is the vaccine-specific antibody response in milk comparable to a natural infection? What would be the effect of vaccination on human milk antibodies in women with past SARS-CoV-2 infection? FindingsIn this prospective, observational and multicenter study in Spain, lactating women within the priority groups receiving the vaccination against SARS-CoV-2 were included. Although there is a high intra- and inter-variability in the generation of specific SARS-CoV-2 antibodies in breast milk, they are also dependent on the vaccine-type and previous viral exposure. MeaningMaternal SARS-CoV-2 vaccination provides anti-SARS-CoV-2 antibodies, both IgA and IgG, in human milk and it depends on vaccines and previous COVID-19.
Subject(s)
COVID-19ABSTRACT
BackgroundDuring 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/MethodsA 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. ResultsAll 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). ConclusionsConsidering 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.