Table 3.
Analysis of antibodies to SARS-CoV-2 in human breastmilk.
| Ref. | Year | Type of Study | Sample | Results | Conclusions |
|---|---|---|---|---|---|
| [45] | 2021 | Prospective cohort group study | 131 (31 lactating women) | IgA, IgM and IgG antibodies were found in the 31 breastmilk samples from vaccinated mothers. The second dose of the vaccine produced an increase in SARS-CoV-2-specific IgG, but not in IgA. Immune transfer to neonates was observed through breastmilk. | COVID-19 mRNA vaccines generated robust humoral immunity in lactating women. Immune transfer to neonates occurred through the placenta and breastmilk. |
| [80] | 2020 | Ambispective, observational clinical analysis | 4 | Three breastmilk samples tested positive for SARS-CoV-2 IgM or IgG. Three neonates tested positive for IgG. One neonate tested positive for IgM within 24 h after birth. | Breastfeeding has a low risk of transmitting SARS-CoV-2. Mothers should continue to breastfeed, but take precautions. Babies may benefit from direct acquisition of SARS-CoV-2 antibodies |
| [81] | 2021 | Prospective longitudinal study | 18 | Of the 18 breastmilk samples collected from the 18 infected mothers, all tested negative for SARS-CoV-2 by RT-PCR. Breastmilk contained anti-SARS-CoV-2 IgA and IgG that neutralised the activity of SARS-CoV-2. | Breastmilk produced by infected mothers is a beneficial source of anti-SARS-CoV-2 IgA and IgG and is capable of neutralising the activity of the virus. These results support recommendations to continue breastfeeding during mild to moderate illness. |
| [82] | 2020 | A case report | 1 | The breastmilk sample collected from the infected mother was negative for SARS-CoV-2 by RT-PCR. IgA and IgG antibodies were found in the sample. | IgG and IgA in breastmilk can provide immune protection. |
| [83] | 2021 | Prospective cohort group study | 84 (504 breastmilk samples) | IgA antibodies were found in 86.1% of the samples and IgG in 97% of the samples. These antibodies showed neutralising effects of the virus. | Robust secretion of SARS-CoV-2 specific IgA and IgG was found in breastmilk after maternal vaccination with virus neutralisation, suggesting a potential protective effect against infection in the infant. |