[1] STANFORD UNIV,MED CTR,SCH MED,DEPT MED,DIV INFECT DIS,STANFORD,CA 94305
[2] STANFORD UNIV,MED CTR,SCH MED,DEPT MED,DIV IMMUNOL,STANFORD,CA 94305
[3] HOP CLAUDE BERNARD,CENT VIROL LAB,F-75994 PARIS 19,FRANCE
[4] INST PASTEUR,DEPT VIROL,UNITE ONCOL VIRAL,F-75724 PARIS 15,FRANCE