[1] HOKKAIDO UNIV SCH, DEPT INTERNAL MED 3, SAPPORO, HOKKAIDO, JAPAN
[2] ORAVAX INC, CAMBRIDGE, MA 02139 USA
[3] VANDERBILT UNIV, SCH MED, DEPT MED, NASHVILLE, TN 37240 USA
[4] VANDERBILT UNIV, SCH MED, DEPT MICROBIOL & IMMUNOL, NASHVILLE, TN 37240 USA