Summary In view of the scarcity of data to guide decision making, we evaluated how BNT162b2 and mRNA-1273 vaccines affect the immune response in lactating women and the protective profile of breastmilk. Compared with controls, lactating women had a higher frequency of circulating RBD memory B cells and higher anti-RBD antibody titers but similar neutralizing capacity. We show that upon vaccination, immune transfer to breastmilk occurs through a combination of anti-spike secretory IgA (SIgA) antibodies and spike-reactive T cells. Although we found that the concentration of anti-spike IgA in breastmilk might not be sufficient to directly neutralize SARS-CoV-2, our data suggest that cumulative transfer of IgA might provide the infant with effective neutralization capacity. Our findings put forward the possibility that breastmilk might convey both immediate (through anti-spike SIgA) and long-lived (via spike-reactive T cells) immune protection to the infant. Further studies are needed to address this possibility and to determine the functional profile of spike T cells. Graphical abstract Highlights • Immune transfer to breastmilk occurs through spike SIgA, IgG, and T cells • mRNA vaccines induce antibody production by the mammary mucosa • Repeated feedings possibly lead to cumulative transfer of neutralizing spike IgA • Vaccination induces higher frequency of RBD + memory B cells in lactating women Gonçalves et al. show that lactating women vaccinated with the Pfizer and Moderna anti-COVID-19 mRNA vaccines transfer to breastmilk spike-reactive secretory antibodies (SIgA) and T cells. These findings advance the possibility that breastmilk might convey both immediate antibody-mediated and long-lived cellular-mediated immune protection to the infant.
【저자키워드】 COVID-19, mRNA vaccine, memory B cells, plasmablasts, milk-transferred SARS-CoV-2 protection, spike SIgA, milk-transferred spike-reactive T cells, lactating women, maternal vaccination, breastmilk T cells, 【초록키워드】 SARS-CoV-2, IgG, immune response, vaccination, antibody, BNT162b2, Pfizer, RBD, IgA, Antibody titer, Neutralizing, breastmilk, neutralizing capacity, Anti-spike, memory B cell, Moderna, Protective, immune protection, Combination, Frequency, Concentration, neutralization capacity, anti-RBD, secretory IgA, mucosa, antibody production, mRNA-1273 vaccine, Abstract, transfer, circulating, cumulative, SIgA, Affect, controls, effective, neutralize, evaluated, functional, determine, occur, induce, immune transfer, mammary, 【제목키워드】 mRNA vaccination, IgA, SARS-CoV-2 spike protein, breastmilk, secretory, transferred,