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

Dynamic Changes in Antibodies and Proteome in Breast Milk of Mothers Infected with Wild-Type SARS-CoV-2 and Omicron: A Longitudinal Study

Background: Breast milk confers essential passive immunity to infants, particularly during viral pandemics. This study investigates dynamic changes in SARS-CoV-2-specific antibodies and proteome in the breast milk of mothers infected with either the wild-type or Omicron variants, addressing gaps in longitudinal dynamics and conserved or variant-specific immune responses. Methods: A prospective cohort of 22 lactating mothers infected with Omicron variant (December 2022-January 2023) was analyzed alongside a published dataset of wild-type-infected mothers (January-May 2020). Breast milk samples were collected at eight time points (1, 4, 7, 14, 21, 28, 35, 42 days post-infection) from the Omicron cohort for ELISA quantification of SARS-CoV-2-specific IgA, IgG, and IgM. Proteomic analysis was conducted for both cohorts. Results: Macronutrient composition remained stable throughout the post-infection period. SARS-CoV-2-specific IgA and IgG demonstrated biphasic kinetics, rapidly rising by day 14 (IgA: 0.03 to 0.13 ng/mL; IgG: 0.91 to 37.00 ng/mL) and plateauing through day 42. In contrast, IgM levels remained unchanged. Proteomic profiling identified 135 proteins associated with IgA/IgG dynamics, including variant-specific and conserved proteins. Conclusions: Breast milk maintains nutritional integrity while mounting robust immune responses during SARS-CoV-2 infection. These findings underscore breastfeeding as a safe and protective practice during COVID-19.

Effects of different sources of lactoferrin on cytokine response to SARS-COV-2, respiratory syncytial virus, and rotavirus infection in vitro

Lactoferrin (Lf) is a multifunctional iron-binding glycoprotein, involved in a wide range of bioactivities, including immunomodulatory and antiviral activities. Lf in human milk and bovine Lf added to infant formula may provide some protection against viral infections. However, functions of Lfs from different sources may differ due to varying manufacturing processes and posttranslational modifications. Here, effects of Lfs (11 commercial bovine milk Lfs, 2 recombinant Lfs, and native human/bovine milk Lf) on cytokine responses to virus infection were examined by infecting human intestinal epithelial cells (Caco-2 cells) with rotavirus (naked) or normal human bronchial epithelial cells (BEAS-2B cells) with respiratory syncytial virus (RSV, enveloped) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein 1. Effects of Lf on viral infection were evaluated by quantitative real-time polymerase chain reaction analysis of transcripts of cytokines/chemokines (TNF-α, IL-1β, IL-6, IL-8, IL-10, IFN-β, and CXCL10). Our results show that viral infection changes transcription of these cytokines and that Lfs significantly and variously influence immune responses to rotavirus, RSV, and SARS-CoV-2 in vitro. Thus, Lf may provide protection against virus infection by down-regulating pro-inflammatory cytokine/chemokine responses. Recombinant bovine and human Lf show similar effects as bovine milk Lfs suggesting that different posttranslational modifications do not affect the antiviral activity on cytokine response.

Vitamin B12 concentrations vary greatly in milk donated to a large provincial milk bank, and are influenced by supplementation and parity

BACKGROUND & AIMS

Feeding parent's milk with supplemental donor milk (DM) is the optimal way to feed very low birth weight (VLBW) infants instead of formula; however, suboptimal neurodevelopment persists. This is believed due, in part, to suboptimal nutrition. Given vitamin B12's role in neurodevelopment and increased adoption of plant-based diets among females of child-bearing age, we aimed to determine the adequacy of vitamin B12 in DM (n = 380 donors) and associated donor characteristics.

METHODS

Vitamin B12 was measured in consecutive raw DM donations received at the milk bank from March 2020-2021 using a validated competitive chemiluminescent enzyme immunoassay (IMMULITE 2000, Siemens). Donor characteristics were obtained from screening records and associations with milk vitamin B12 concentrations explored using a generalized additive model.

RESULTS

Donors were 32 ± 4 years old (mean ± SD), and DM was expressed 98 ± 85 days postpartum. Vitamin B12 concentrations in DM had a median (25th, 75th percentile) of 232 (149, 373) pmol/L; 64 % had concentrations <310 pmol/L (common cut-off for inadequacy in healthy term-born infants). In a multivariable analysis, donors consuming a vitamin B12-containing supplement had higher DM vitamin B12 (β ± SE: 80.3 ± 25.4 pmol/L; p = 0.020) compared to those not taking a supplement. Primiparous donors had higher DM vitamin B12 than multiparous donors (36.7 ± 18.2 pmol/L greater; p = 0.044). No associations were observed for other donor characteristics.

CONCLUSION

Milk donated to a large human milk bank showed evidence of suboptimal vitamin B12; levels were associated with both donor vitamin B12-containing supplement use and parity. Further research as to whether and when milk bank donors are recommended to consume a supplement and the benefits and risks of routine vitamin B12 supplementation of DM-fed infants is warranted.

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.