[Poliovirus (Sabin strain) multiplication in human intestinal tract after oral polio vaccination].

Fecal specimens from a baby vaccine were collected every day from 1 to 51 days after primary vaccination and from 0 to 15 days after secondary vaccination. Polioviruses were isolated with GMK-2 cell line from 10% emulsion of the feces and titrated the virus contents in the emulsion of the feces. The isolated viruses were tested the reproductive capacity at 39.0 degrees C and 39.5 degrees C by the plaque method with primary cynomologous monkey kidney cells. Viruses were isolated from the feces during 28 days for type 1, 39 days for type 2 and 36 days for type 3 after primary vaccination, however, only type 1 viruses were isolated during 7 days after secondary vaccination. The multiplication of type 3 viruses in the intestine were increased after diminished the multiplication of type 1 and type 2. In plaque formation capacity at 39.0 degrees C and 39.5 degrees C, the isolates had shown to differ clearly among the types of poliovirus. After primary vaccination, type 1 isolates were not produced the plaques at 39.0 degrees C and 39.5 degrees C. Although type 2 isolates were not formed the plaques until the 14th day at 39.5 degrees C, the plaque formation capacity of the these isolates were increased gradually i.e.; on the 20th day (10(0.88) PFU/ml), the 26th day (10(2.00) PFU/ml) and the 39th day (10(2.63) PFU/ml) at 39.5 degrees C, and all of type 2 isolates tested were showed the plaque formation capacity (10(2.88 approximately 10(3.76) PFU/ml) at 39.0 degrees C. Type 3 isolates were formed plaques at 39.0 degrees C and 39.5 degrees C from the 7th day. After the secondary vaccination, type 1 isolates (7th day) was a little changed them. Neutralizing antibody titers were shown that type 1 was 320, type 2 was 110 and type 3 was 60 after 1 year of the second administration. These titers were closely similar the geometric mean titers of 2 year old babies in Japan.