Cord blood antibodies following BBIBP‐CorV (Sinopharm) vaccination during pregnancy

OBJECTIVE: This study aimed to evaluate the maternal and umbilical cord blood antibody levels, after COVID vaccination during pregnancy. METHOD: The women who received the COVID‐19 vaccine (Sinopharm) during pregnancy were included. Maternal and cord blood samples were tested to detect the severe acute respiratory syndrome coronavirus 2 receptor binding domain (RBD) specific antibodies. In addition, obstetric information and side effects after vaccination were gathered. RESULT: A total of 23 women were included. Eleven pregnant women took two doses and 12 cases received a single dose of the vaccine. No IgM antibody was detected in any maternal blood or cord blood samples. The RBD‐specific Immunoglobulin G (IgG) antibody was positive in mothers receiving 2 doses of the vaccine and their infants. But the antibody titers were under the positive cut‐off threshold for the other 12 women who were vaccinated with a single dose. Women who received both doses of vaccine had significantly higher IgG levels than a single dose of Sinopharm (p = .025). The same result was demonstrated in infants born to these mothers (p = .019). CONCLUSION: There was a significant correlation between maternal and neonatal IgG concentrations. Although, receiving both doses of the BBIBP‐CorV vaccine (not 1 dose) during pregnancy is highly beneficial for increasing humoral immunity for the mother and fetus.