TABLE 2.

Maternal and cord blood seroconversion and breast milk antibodies

Author	Antibodies in breast milk	Seropositivity in maternal blood	Seropositivity in cord blood
	N positive/N tested (antibody–antigen)
Esteve‐Paula et al. 23	18/18 (IgG–S1)	18/18 (IgG–S1)	N/A
Low et al. 28	10/10 (IgG–spike)	N/A	N/A
	10/10 (IgG–RBD)
	9/10 (IgA–spike)
	9/10 (IgA–RBD)
Selma‐Royo et al. 29	Moderna and Pfizer	N/A	N/A
	40/40 (IgG–RBD)
	24/40 (IgA–RBD)
	AZ
	17/20 (IgG–RBD)
	6/20 (IgA–RBD)
Collier et al. 16	N/S	44/44 (IgG–RBD)	9/9 (IgG–RBD)
Beharier et al. 17	N/A	N/S	N/S
Gray et al. 18	N/S	N/S	10/10 (IgG–RBD)
			10/10 (IgG–spike)
Mithal et al. 19	N/A	26/27 (IgG–RBD)	25/28 (IgG–RBD)
		15/27 (IgM–RBD)	0/28 (IgM–RBD)
Perl et al. 30	68/70	N/A	N/A
Friedman et al. 24	N/S	N/S	N/A
Golan et al. 25	13/15 (IgA–RBD)	14/14 (IgG–RBD)	N/A
Prabhu et al. 20	N/A	87/122 (IgG–S‐RBD)	N/S
Rottenstreich et al. 21	N/A	20/20 (IgG–RBD)	20/20 (IgG–RBD)
		20/20 (IgG–spike)	20/20 (IgG–spike)
		6/20 (IgM–S1 RBD)	0/20 (IgM–S1‐RBD)
Shanes et al. 39	N/A	30/52 (IgM–spike)	N/A
		50/52 (IgG–spike)
Atyeo et al. 22	N/S	N/S	N/S
Fox et al. 31	10/10 (IgG–spike)	N/A	N/A
	6/10 (IgA–spike)
Valcarce et al. 26	18/21 (IgA–?)	18/21 (IgA–?)	N/A
	10/10 (IgG–?)	21/21 (IgG–?)
Juncker et al. 27	26/26 (IgA–spike)	26/26 (IgG–spike)	N/A

Abbreviations: N/A, study did not assay for humoral response in this sample type; N/S, study did not specify antibody conversion rates.