Immunity to Vibrio cholerae in the mouse. I. Passive protection of newborn mice.

Mice were immunized subcutaneously with either killed cells or a ribosome-containing fraction (RF) obtained from Vibrio cholerae Ogawa 41. At appropriate time intervals, these mice or their progeny were challenged with uniformly lethal doses of Ogawa or Inaba serotype. Half of the offspring born to mice immunized with 20 mug of RF were protected against homologous challenge at 7.5 weeks of age, and significant protection was observed up to 15 weeks of age. Similar protection was observed with heterologous challenge, but the duration of protection was reduced. The duration of protection obtained in newborns was related to the quantity of RF given to the mother. Protection was transferred from mother to young via colostrum or milk. Protection was not due to transfer of antigen, as active immunity could not be induced in newborn mice immunized with RF.