GBS6 induced maternal antibody responses to all serotypes, with maternal-to-infant antibody ratios varying based on dose<\/p>\n<\/h3>\n
By Elana Gotkine HealthDay Reporter<\/b><\/p>\n
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FRIDAY, July 21, 2023 (HealthDay News) — A hexavalent capsular polysaccharide (CPS)-cross-reactive material 197 glycoconjugate vaccine (GBS6) can prevent invasive group B streptococcus in young infants, according to a study published in the July 20 issue of the New England Journal of Medicine<\/em>.<\/p>\n Shabir A. Madhi, M.D., Ph.D., from the South African Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit in Johannesburg, and colleagues conducted an ongoing phase 2, placebo-controlled trial involving pregnant women to assess the safety and immunogenicity of a single dose of various GBS6 formulations and analyzed maternally transferred anti-CPS antibodies. In a parallel seroepidemiologic study, serotype-specific anti-CPS immunoglobulin G (IgG) concentrations that were associated with a reduced risk for invasive disease among newborns were assessed to define putative protective thresholds.<\/p>\n The researchers found that among infants in the seroepidemiologic study, naturally acquired anti-CPS IgG concentrations were associated with a reduced risk for disease. IgG thresholds of 0.184 to 0.827 \u00c2\u00b5g\/mL were determined to be associated with 75 to 95 percent reductions in the risk for disease. There were no GBS6-associated safety signals among mothers or infants. Across the trial groups, the incidence rates of adverse events and serious adverse events were similar for mothers and infants; the groups that received GBS6 containing aluminum phosphate had more local reactions. GBS6 induced maternal antibody responses to all serotypes; depending on the dose, maternal-to-infant antibody ratios were approximately 0.4 to 1.3.<\/p>\n “The potential protective concentrations that are reported herein are based on a single seroepidemiologic study,” the authors write. “Future studies are needed to better define these immunologic relationships.”<\/p>\n The study was funded by Pfizer.<\/p>\n Abstract\/Full Text<\/a><\/p>\n Editorial (subscription or payment may be required)<\/a><\/p>\n <\/i><\/p>\n