[1] KAROLINSKA INST,STOCKHOLM CTY COUNCIL,DEPT CLIN VIROL,MICROBIOL CENT LAB,S-14186 HUDDINGE,SWEDEN
[2] KAROLINSKA INST,HUDDINGE HOSP,DEPT CLIN VIROL,S-14186 HUDDINGE,SWEDEN
[3] KAROLINSKA INST,HUDDINGE HOSP,DEPT CLIN VIROL IMMUNOL,S-14186 HUDDINGE,SWEDEN
[4] KAROLINSKA INST,DEPT TUMOR BIOL,S-10401 STOCKHOLM 60,SWEDEN