Maternal immunization with P fimbriae for the prevention of neonatal pyelonephritis.

Rhesus monkeys (Macaca mulatta) were immunized with purified P fimbriae from Escherichia coli during the last trimester of pregnancy. Infants born of these mothers were compared with those from nonimmunized rhesus mothers. A delay in the onset of renal disease after bladder infection showed protection from passive immunization. This was associated with a high antibody titer in serum. In addition to delayed onset of renal infection, a decreased number of immunized monkeys developed pyelonephritis.