Should we continue breastfeeding after SARS-CoV-2 infection or mRNA vaccination?

ABSTRACT

The coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed a potential threat to infant health. The World Health Organization recommended that the benefits of breastfeeding far outweigh the potential risk of transmission, but there is no denying that the current evidence is insufficient. Moreover, although the COVID-19 mRNA vaccine has played an effective role in protection against infection, individuals have increasing concerns about the safety of breastfeeding after vaccination, and which have caused some breastfeeding women to postpone vaccination or stop breastfeeding early. Thus, in this review, we provide an in-depth discussion of whether SARS-CoV-2 and the vaccine will affect babies through breast milk. On one hand, only a very small number of milk samples were identified positive for viral RNA and almost impossible to be live virus particles. The milk of most lactating women after vaccination did not contain vaccine-related mRNA and polyethylene glycol. On the other hand, the antibodies and biologically active molecules like lactoferrin are abundant in the milk of lactating women who have been infected or vaccinated, which can provide potential protection against infants' respiratory and gastrointestinal infections. Therefore, in terms of implications for clinical practice, the results of our study support that lactating women who have been infected or vaccinated should be encouraged to breastfeed their infants under the premise of taking appropriate sanitary measures. © 2022 Centro Regional de Invest. Cientif. y Tecn.. All rights reserved.