Level of Maternal Antibody Required to Protect Neonates against Early-Onset Disease Caused by Group B Streptococcus Type Ia: A Multicenter, Seroepidemiology Study

• Published in: The Journal of infectious diseases Vol. 184; no. 8; pp. 1022 - 1028
• Main Authors: Lin, Feng-Ying C., Philips, Joseph B., Azimi, Parvin H., Weisman, Leonard E., Clark, Penny, Rhoads, George G., Regan, Joan, Concepcion, Nelydia F., Frasch, Carl E., Troendle, James, Brenner, Ruth A., Gray, Barry M., Bhushan, Reva, Fitzgerald, Geri, Moyer, Patricia, Clemens, John D.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 15.10.2001; University of Chicago Press
• Subjects: Age of Onset; Antibodies, Bacterial - blood; Bacterial diseases; Biological and medical sciences; Female; Fetal Blood - immunology; Human bacterial diseases; Human viral diseases; Humans; Immunity, Maternally-Acquired; Immunoglobulin G - blood; Infant, Newborn; Infectious diseases; Medical sciences; Predictive Value of Tests; Pregnancy; Pregnancy Complications - immunology; Staphylococcal infections, streptococcal infections, pneumococcal infections; Streptococcal Infections - immunology; Streptococcal Infections - prevention & control; Streptococcus; Streptococcus agalactiae - immunology; Viral diseases; Viral diseases of the lymphoid tissue and the blood. Aids; Human; Antibody; Multicenter study; IgG; Infant; Vaccine; Infection; Streptococcaceae; Specificity; Streptococcal infection; Streptococcus B; Streptococcus A; Bacteriosis; Bacteria; Micrococcales; Serum; ELISA assay
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1086/323350

Because of the difficulty of conducting efficacy trials of vaccines against group B streptococcus (GBS), the licensure of these vaccines may have to rely on studies that measure vaccine-induced antibody levels that correlate with protection. This study estimates the level of maternal antibody required to protect neonates against early-onset disease (EOD) caused by GBS type Ia. Levels of maternal serum IgG GBS Ia antibodies, measured by ELISAs in 45 case patients (neonates with EOD caused by GBS Ia) and in 319 control subjects (neonates colonized by GBS Ia but without EOD) born at ⩾34 weeks gestation were compared. The probability of developing EOD declined with increasing maternal levels of IgG GBS Ia antibody (P=.03). Neonates whose mothers had levels of IgG GBS Ia antibody ⩾5 μg/mL had an 88% lower risk (95% confidence interval, 7%–98%) of developing type-specific EOD, compared with those whose mothers had levels <0.5 μg/mL. A vaccine that induces IgG GBS Ia antibody levels ⩾5 μg/mL in mothers can be predicted to confer a high degree of type-specific immunity to EOD to their infants