Assessment of maternal and neonatal igg antibodies titres against sars-cov-2 – a cross sectional cohort study from a tertiary care hospital

The impact of the COVID-19 pandemic on maternal and neonatal health has been insidious, yet comparatively less studied in present research. Reports have shown that IgG antibodies against SARS-CoV-2 can be transmitted vertically, but the efficacy and rate remain insufficiently evaluated. Some studies approximated 50% SARS-CoV-2 IgG antibody transfer from mother to child, whereas others showed higher titres in mothers infected with COVID-19 rather than vaccinated. The present study aimed to assess maternal and neonatal SARS-CoV-2 antibody titres and find correlations between them. A total of 92 mother/child dyads (total n=182) were recruited from Vani Vilas Hospital, a specialised women’s and children hospital in Bangalore. The maternal blood and neonatal blood samples were drawn after informed consent from the mother was taken. Qualitative detection of IgG antibodies against S1 protein was done by standard ELISA method using COVID KAWACH IgG MICROLISA, J. Mitra & Co. Pvt. Ltd. Basic demographic details and SARS-CoV-2 vaccine history were obtained from the pregnant women. The data was analysed using SPSS software version 23.0, and appropriate parametric and non-parametric tests such as Chi-square test, paired and unpaired t-test were used wherever applicable. A p-value less than 0.05 was considered significant. Of the 92 women in the present study, the ages were 19 to 33 years with a mean of 25 ± 3 years. 71 out of 92 women had received the Covishield vaccine, and the rest with Covaxin. Their mean antibody titre was 1.7124 ± 0.9429. Almost all the mothers (91 out of 92) had positive antibody titres post vaccination. Positive IgG antibody titres against SARS-CoV-2 were found in neonatal serum, confirming the transplacental transfer of IgG antibodies to the neonates. 78 (84.8%) neonates had positive IgG titres. There was a strong positive correlation (ρ=0.887) between maternal and neonatal titres (p-value <0.0001). There was no significant correlation between blood group, type of vaccine and the antibody titres. The results of the present study implicate the transplacental transfer of IgG antibodies against SARS-CoV-2. This supports the current recommendation for pregnant women to receive the SARS-CoV-2 vaccination. Thus, boosting maternal immunity during pregnancy translates into measurable seropositivity in the child, which may result in a milder course of clinical neonatal disease. This data aids in developing an optimal vaccine schedule for both pregnant mother and child.