Detection of SARS-CoV-2 Neutralizing Antibodies in Vaccinated Pregnant Women and Neonates by Using a Lateral Flow Immunoassay Coupled with a Spectrum-Based Reader

Abstract

The focus of this study was to investigate the detection of neutralizing antibodies (Nabs) in maternal serum and cord blood as the targeted samples by employing a lateral flow immunoassay combined with a spectrum reader (LFI-SR) and the correlation of Nab protection against different types of SARS-CoV-2. We enrolled 20 pregnant women who were vaccinated with the Moderna (mRNA-1273) vaccine during pregnancy and collected 40 samples during delivery. We used an LFI-SR for the level of spike protein receptor binding domain antibody (SRBD IgG) as Nabs and examined the correlation of the SRBD IgG concentration and Nab inhibition rates (NabIR) via enzyme-linked immunosorbent assays (ELISA). The LFI-SR had high confidence for the SRBD IgG level (p < 0.0001). Better NabIR were found in wild-type SARS-CoV-2 (WT) compared to Delta-type (DT) and Omicron-type (OT). Women with two-dose vaccinations demonstrated greater NabIR than those with a single dose. The cut-off value of the SRBD IgG level by the LFI-SR for NabIR to DT (≥30%; ≥70%) was 60.15 and 150.21 ng/mL for mothers (both p = 0.005), and 156.31 (p = 0.011) and 230.20 ng/mL (p = 0.006) for babies, respectively. An additional vaccine booster may be considered for those mothers with SRBD IgG levels < 60.15 ng/mL, and close protection should be given for those neonates with SRBD IgG levels < 150.21 ng/mL, since there is no available vaccine for them.

Research progress in methods for detecting neutralizing antibodies against SARS-CoV-2

“…In the early 1980s, immunochromatography was used to detect human chorionic gonadotropin, and most of the results were qualitative. Traditional immunochromatography mostly uses colloidal gold as a probe [ 81 ]. Recently, immunochromatography has developed robustly in biomedicine, environmental monitoring, food engineering, etc [ 82 ].…”

TRAIL and IP-10 dynamics in pregnant women post COVID-19 vaccination: associations with neutralizing antibody potency

“…Vaccination against COVID-19 for pregnant women allow mothers to produce and transfer protective antibodies to their fetus ( Shen et al., 2022 ). Specifically, the transplacental transmission of SARS-CoV-2 neutralizing antibodies (Nabs) has shown potential in protecting fetuses and neonates ( Shen et al., 2022 ; Chen et al., 2022a ), and this protection can also be observed for newly-evolved SARS-CoV-2 variants including Omicron variants ( Chen et al., 2022b ; Munoz et al., 2023 ). According to current research, COVID-19 vaccination in pregnant women does not increase the risk of any adverse pregnancy, maternal, or neonatal outcomes.…”