Difference in levels of SARS-CoV-2 S1 and S2 subunits- and nucleocapsid protein-reactive SIgM/IgM, IgG and SIgA/IgA antibodies in human milk. - Demers-Mathieu V; Do DM; Mathijssen GB; Sela DA; Seppo A; Järvinen KM; Medo E (Journal of perinatology : official journal of the California Perinatal Association, 2021)