All participants will start with Treatment A followed by a 7 or 8-day washout period. Subsequently, participants will start with Treatment B. At the end of Treatment B, participants will be randomized (this is assigned to one of the two sequences by chance) to continue without a washout period with Sequence 1 (Treatment C followed by D without a washout) or Sequence 2 (Treatment D followed by C without a washout). Participants will thus receive daily EFV and TDF for a total of 21 consecutive days, with addition of 2 different dosages of TVR for the last 14 days.