Therapeutic potential of human antisera to group B streptococcal glycoconjugate vaccines in neonatal mice

Experimental immunoglobulin preparations for treatment of group B streptococcal (GBS) infections contain low levels of functional antibody and exhibit lot-to-lot variability, GBS capsular polysaccharide-protein conjugate vaccines have recently been shown to produce high serum levels of type-specific antibody in healthy volunteers, Treatment of neonatal mice 4 h after inoculation with an ordinarily lethal dose of GBS type Ia, Ib, or III with pooled human serum from adults who had received GBS type Ia capsular polysaccharide-tetanus toroid vaccine (la CPS-TT), Ib CPS-TT, or In CPS-TT resulted in 63%, 70%, and 75% survival, respectively, In contrast, less than or equal to 17% of the infected mice treated with normal human serum or saline survived, These results demonstrate the therapeutic activity of GBS polysaccharide conjugate vaccine-induced antiserum and provide a rationale for the use of these vaccines in producing a functional, high-titered intravenous immunoglobulin preparation for clinical use.