[Serum opsonic activity in newborns and through the first year of life (author's transl)].

Serum opsonic capacity for "Staph. aureus" was studied in 58 full term infants at birth and through their 1st year of life. The comparison between serum opsonic activity from the infants and their mothers disclosed that infants had a significant decrease of the opsonic activity during the first three months of life. The study of serum levels of C3, C4, IgG and IgM, showed a significant correlation between opsonizationa and low levels of the complement components C3 and C4.