aDepartment of Virology, Swedish Institute for Infectious Disease Control, and Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SwedenbDepartment of Medicine, Solna, Infectious Disease Unit, Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital, SwedencDepartment of Clinical Science and Education, Karolinska Institutet, Södersjukhuset, Unit, Gay Men's Health Clinic (Venhälsan), Stockholm, Sweden.