Journal Article

Anti-SARS-CoV-2 IgA and IgG in human milk after vaccination is dependent on vaccine type and previous SARS-CoV-2 exposure: a longitudinal study

Martínez-Costa, Cecilia, Collado, Maria Carmen, Aguilar-Camprubí, Laia, Parra-Llorca, Anna, Pérez-Cano, Francisco J., Bäuerl, Christine, Mena-Tudela, Desirée, Selma-Royo, Marta, Lerin, Carles

2022

Overview

Background Breast milk is a vehicle to transfer protective antibodies from the lactating mother to the neonate. After SARS-CoV-2 infection, virus-specific IgA and IgG have been identified in breast milk, however, there are limited data on the impact of different COVID-19 vaccine types in lactating women. This study is aimed to evaluate the time course of induction of SARS-CoV-2-specific IgA and IgG in breast milk after vaccination. Methods In this prospective observational study in Spain, 86 lactating women from priority groups receiving the vaccination against SARS-CoV-2 were included. Breast milk samples were collected longitudinally at seven or eight-time points (depending on vaccine type). A group with confirmed SARS-CoV-2 infection ( n =19) and a group of women from pre-pandemic time ( n =20) were included for comparison. Results Eighty-six vaccinated lactating women [mean age, 34.6 ± 3.7 years] of whom 96% were Caucasian and 92% were healthcare workers. A total number of 582 milk samples were included, and vaccine distribution was BioNTech/Pfizer (BNT162b2, n =34), Moderna (mRNA-1273, n =20), and AstraZeneca (ChAdOx1 nCoV-19, n =32). For each vaccine, 7 and 8 longitudinal time points were collected from baseline up to 30 days after the second dose for mRNA vaccines and adenovirus-vectored vaccines, respectively. A strong reactivity was observed for IgG and IgA after vaccination mainly after the 2 nd dose. The presence and persistence of specific SARS-CoV-2 antibodies in breast milk were dependent on the vaccine type, with higher IgG and IgA levels in mRNA-based vaccines when compared to AstraZeneca, and on previous virus exposure. High intra- and inter-variability were observed, being relevant for IgA antibodies. In milk from vaccinated women, anti-SARS-CoV-2 IgG was significantly higher while IgA levels were lower than in milk from COVID-19-infected women. Women with previous COVID-19 increased their IgG antibodies levels after the first dose to a similar level observed in vaccinated women after the second dose. Conclusions COVID-19 vaccination induced anti-SARS-CoV-2 IgA and IgG in breast milk with higher levels after the 2 nd dose. Levels of anti-SARS-CoV-2 IgA and IgG are dependent on the vaccine type. Further studies are warranted to demonstrate the protective antibody effect against COVID-19 in infants from vaccinated and infected mothers. Trial registration NCT04751734 (date of registration is on February 12, 2021)

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adenoviruses / Adult / Analysis / Antibodies / Antibodies, Viral / Bioinformatics / Biomedical and Life Sciences / Biomedicine / BNT162 Vaccine / Breast milk / Breastfeeding & lactation / Cancer Research / ChAdOx1 nCoV-19 / Coronavirus Resource / Coronaviruses / COVID-19 - prevention & control / COVID-19 Vaccines / Female / Health aspects / Human Genetics / Humans / Immunoglobulin A / Immunoglobulin G / Immunoglobulins / Infant / Infant, Newborn / Infants / Infection / Infections / Lactation / Longitudinal Studies / Medical personnel / Medical research / Medicine, Experimental / Medicine/Public Health / Metabolomics / Milk, Human / Mothers / mRNA / mRNA vaccines / Pandemics / Pharmaceutical industry / Proteins / RNA / SARS-CoV-2 / Severe acute respiratory syndrome coronavirus 2 / Standard deviation / Statistical analysis / Systems Biology / Vaccination / Vaccines / Womens health