aDepartment of HIV/GUM, Chelsea and Westminster Hospital

bDepartment of Infectious Diseases, Imperial College London, London, UK

cDepartment of Pharmacy Practice and Science, University of Nebraska Medical Center, Omaha, Nebraska, USA

dDepartment of Immunobiology, Queen Mary University, London, UK

Correspondence to Marta Boffito, London, UK. E-mail: [email protected]