Methods
SARS-CoV-2 antibodies against the nucleocapsid (anti-N), receptor-binding domain of the spike protein (anti-S), and the neutralizing antibody (nAb) titers against different SARS-CoV-2 variants were measured for the maternal-cord pairs. The participants were categorized based on the timing of their last vaccination, including during the third (T3) and second trimesters (T2) and before/during the first trimester (T1). Comparison of anti-spike protein antibody and neutralizing antibody concentrations was analyzed using the Kruskal-Wallis test followed by a post-hoc Mann-Whitney U test.