S. Yerly , V. von Wyl , J. Böni , J. Schüpbach , P. Burgisser, T. Klimkait, M. Rickenbach, B. Ledergerber, H. Günthard, L. Perrin, and the Swiss HIV Cohort Study. Poster presented during the Forum for Collaborative HIV Research Standardization & Clinical Relevance of HIV Drug Resistance Working Group Meeting. Sitges, 2006. This email address is being protected from spambots. You need JavaScript enabled to view it.