Perinatal transmission of SARS-CoV-2 and transfer of maternal IgG/neutralizing anti-SARS-CoV-2 antibodies from mothers with asymptomatic infection during pregnancy

Abstract

Purpose COVID-19 pandemic remains a serious public health threat worldwide. In view of the limited data on the risk of perinatal transmission of SARS-CoV-2 and transfer of maternal anti-SARS-CoV-2 antibodies, the present study was undertaken. Methods A prospective study including 57 pregnant women with a positive SARS-CoV-2 RNA test (SARS-CoV-2-RNA+) and 59 neonates born to them was conducted at Pune, India. 39 viral RNA negative (SARS-CoV-2-RNA-negative) pregnant women and their 39 neonates were included as controls. Neonatal nasal swab/cord blood samples were subjected to SARS-CoV-2 RNA detection by RT-PCR for investigation of perinatal transmission. Transfer of maternal antibodies was studied using ELISA and PRNT. Results 10/57 SARS-CoV-2-RNA+ mothers were symptomatic. The duration between COVID-19 diagnosis and delivery was ≤ 7 days for 82.4%. Perinatal transmission as evidenced by viral RNA in the neonatal nasal swab/cord blood (CB) was 3.6%. IgG-anti-SARS-CoV-2 positivity was 21.6%. Of the 39 neonates born to SARS-CoV-2-RNA-negative mothers, 20 (51%) and none, respectively, were positive for IgG-anti-SARS-CoV-2 and viral RNA. Preterm deliveries were higher in SARS-CoV-2-RNA+ (18.6%) than SARS-CoV-2 RNA-negative (0/39) mothers ( p < 0.005). Respiratory distress at birth (< 4 h) was higher among neonates of SARS-CoV-2-RNA+ (20/59, 33.9%) than SARS-CoV-2-RNA-negative mothers (3/39, 7.7%; p < 0.001). ~ 75% IgG-positives exhibited neutralization potential with mean PRNT titers of 42.4 ± 24 (SARS-CoV-2-RNA+) and 72.3 ± 46.7 (SARS-CoV-2 RNA-negative); higher in the latter ( p < 0.05). Conclusion The rate of perinatal transmission was low. Transfer of maternal antibodies was lower among SARS-CoV-2-RNA+ mothers than SARS-CoV-2-RNA-negative mothers with subclinical infection during pregnancy. Presence of neutralizing antibodies in majority of IgG-positives suggests protection from SARS-CoV-2 in early life.

Immune profiling of SARS-CoV-2 infection during pregnancy reveals NK cell and γδ T cell perturbations

“…RBD-specific IgM and IgA were also measured in the cord blood; however, as these isotypes do not vertically transfer, titers were significantly lower in cord blood compared with maternal blood (Supplemental Figure 1G), and not significantly different from unexposed pregnancy cord blood (Supplemental Figure 1E). Our findings verify reports that SARS-CoV-2 IgG antibodies (30,32,39) and neutralizing antibodies (40,41) cross the placenta, providing a layer of immunity against SARS-CoV-2 infection to the neonate.…”

Preliminary results on transmission of SARS‐CoV‐2 antibodies to the fetus and serum neutralizing activity

“…Joseph et al 2 in a well‐documented study on 32 paired samples (maternal and cord blood) did not show at the threshold of 14 days, a difference in the neutralizing potency but their findings concerned half of asymptomatic patients. Malshe et al 3 showed on nine infant mothers pairs a transfer of neutralizing activity beginning between 2 and 3 weeks after diagnosis.…”

“…If we postulate a similar immune response between natural infection and vaccination, 3 then the vaccination process should end 3 weeks before parturition. Considering the mRNA vaccine calendar the first injection should not be after 32 GA.…”

Angiotensin converting enzyme 2 (ACE2): Virus accomplice or host defender

“…6g). And the comparison of asymptomatic infection in pregnancy is quite high [62][63][64][65][66] (Fig. 6h), which proves the important role of ACE2 in asymptomatic infection.…”