antibody response before and after the booster dose of inactivated corona vaccine in antibody deficient patients

Patients with inborn errors of immunity (iei) are among the high-risk groups regarding covid-19. receiving booster doses (third and fourth) in addition to the standard doses is recommended in these patients. this study investigated the antibody response before and after a booster dose of sinopharm vaccine in iei patients.thirty patients (>12 years) with antibody deficiencies, referred to imam khomeini hospital and children's medical center in tehran, were enrolled in this prospective cross-sectional study. all patients were fully vaccinated with the bbibp-corv vaccine (2 doses of sinopharm). initial measurements of anti-receptor-binding domain (anti-rbd) and anti-nucleocapsid (anti-n) igg antibody responses were conducted by enzyme-linked immunosorbent assay (elisa). subsequently, all patients received a booster dose of the vaccine. four to six weeks after booster injection, the levels of antibodies were re-evaluated.twenty patients with common variable immunodeficiency (cvid), 7 cases with agammaglobulinemia and 3 patients with hyper igm syndrome were studied. anti-rbd igg and anti-n igg antibodies increased in all patients after the booster.our results indicated the need of receiving booster doses of the covid-19 vaccine in patients with antibody deficiencies, even for enhancing humoral immune response specially in patients with cvid.