Passive immunity in newborn from SARS‐CoV‐2‐infected mother

Abstract

Severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) vertical transmission is an open issue. Recent reports call into question in utero or peripartum viral transmission to the offspring. Few data are available on immunoglobulin G (IgG) and/or IgM in newborns. Insufficient evidence is available regarding passive immunity in neonates born from SARS‐CoV‐2 infected women. We report a case of a neonate showing the presence of blood specific IgG and the absence of IgM and negative nasopharyngeal swab. He was born from an asymptomatic SARS‐CoV‐2‐infected mother with positive IgG and IgM. The transplacental passage of specific IgG antibodies from the affected mother to the unaffected fetus highlights neonatal passive immunity.

What do we know about the antibody responses to SARS-CoV-2?

“…IgM was also detected in infants, but it was not identified if it was due to any damage to the placenta, or if the virus crossed the placenta and the baby produced the antibodies, or if the antibodies were actually transferred from mother to child ( Zeng et al, 2020a ). This presence is also mentioned in other reports, disappearing 28 days after delivery ( Cavaliere et al, 2020 ). Additionally, breast milk has also shown IgG and IgA antibodies against SARS-CoV-2 ( Dong et al, 2020 ).…”

A Comprehensive Analysis of Maternal and Newborn Disease and Related Control for COVID-19

“…Blauvelt et al did not find either IgG or IgM in the blood of the preterm newborn [69]. In contrast, others have found newborn IgG but not IgM in an infant born at 38 weeks gestational age whose mother was infected at 29 weeks [143]. In utero transplacental passage of IgG in any regard occurs more readily as the placenta matures.…”

“…For the determination of fetal infection, a time-honored approach could be the determination of IgMvirus specific antibody in newborn immediately in the postnatal period [52]. IgG-based serology for the newborn may be difficult to use since maternal IgG is capable of nonspecifically crossing the placenta for much of late pregnancy [73,117,[142][143][144][145]. Confirmatory or immunoblotting techniques would be useful to validate the likelihood of positive serodiagnoses in the research context at least.…”

“…The common mucosal immune system facilitates the production of sIgA in the breast milk that is common to the respiratory tract. Therefore, mothers who have been infected for more than 10 days will likely have some anti-SARS-CoV-2 antibody transferred to the fetus during the prebirth or will have anti-SARS-CoV-2 sIgA and IgG in milk; quantities of the latter will be considerably variable [143]. The amount of such acquisition by the fetus or newborn is timeaccrued.…”

Is There an Effect of Fetal Mesenchymal Stem Cells in the Mother–Fetus Dyad in COVID-19 Pregnancies and Vertical Transmission?

“…However, there have also been some reports where IgM were detected in the fetus. These include case reports and small studies from China [2 preterm ( Dong et al, 2020 ; Wu et al, 2020d ), 1 term ( Zhou et al, 2020 ), 2 term, 10 term ( Gao J. et al, 2020 ), 2 preterm-1 term ( He et al, 2020 )], the United States [one term ( Edlow et al, 2020 )], Italy [one preterm ( Fenizia et al, 2020 ), one term ( Cavaliere et al, 2020 )], and Sweden (three term Herlenius et al at Karolinska University Hospital, Stockholm, in progress) that also exhibited IgG against SARS-CoV-2 nucleocapsid and S-protein antibodies 0–2 days after birth.…”