[1] Univ Liege, CHU Sart Tilman, Dept Infect Dis & Gen Internal Med, Liege, Belgium
[2] Univ Catholique Louvain, Clin Univ St Luc, Dept Paediat, B-1200 Brussels, Belgium
[3] Henogen, B-6041 Charleroi, Belgium
[4] GlaxoSmithKline Biol, B-1330 Rixensart, Belgium