1. Delft Diagnostic Laboratory, Delft, The Netherlands
2. Initiative for Vaccine Research, Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
3. Viral Quality Control Laboratory, Central Laboratory for Blood Transfusion, Diagnostic Division, Alkmaar, The Netherlands
4. Reference Center for Papillomaviruses, Division for the Characterization of Tumorviruses, Deutsches Krebsforschungszentrum, Heidelberg, Germany
5. Department of Molecular Genetics and Microbiology, School of Medicine, University of New Mexico, Albuquerque, New Mexico