Vivax Malaria

This study is an open label, single arm, pharmacokinetic trial. A total of 20 participants (children ≤12kg and \>28 days old) will be enrolled. Enrollment will be competitive between Thailand and Vietnam study sites (each site will enroll as many patients that are eligible until the sample size is reached). Tafenoquine will be given concomitantly with the schizonticidal agent, chloroquine, on the day of enrolment. The participant will be admitted to hospital for observation and until the malaria smear is negative for asexual parasites on 2 consecutive days or until the schizonticidal treatment is completed, which will be approximately 3-7 days. All treatment doses will be supervised. Follow up will continue on days 7, 14, 21, and 28 then every month until month 4. Parent/guardian of participants will be instructed to follow up in between visits if participants are feeling unwell. Participants who are lost to follow up (any missed visit), who require drug re-administration after vomiting, or where at least 3 pharmacokinetic samples are not successfully drawn, will be replaced. Participants being replaced will continue in the study for safety assessments and to ensure the treatment of recurrences. The total blood drawn for this study will be 3.76 mL if the participant has no recurrences.

A trial designed to determine whether there is a clinically significant drug-drug interaction of tafenoquine with DHA-piperaquine or artesunate-pyronaridine using a control arm with radical cure given at the end of follow up (delayed radical cure).

A non randomized observation study that is aiming to assess the safety and efficacy of high dose primaquine (1mg/kg per day over 7 days) among patients with intermediate (30-70%) G6PD activity and the safety and efficacy of weekly primaquine among patients who are g6Pd deficient (\<30% activity)

The goal of this clinical trial is to assess the efficacy and safety or a revised weight band tafenoquine dose in vivax malaria patients. The main question\[s\] it aims to answer are: * is a revised weight-based TQ regimen (TQRevised: target dose 7.5mg/kg) non-inferior to high dose primaquine (7mg/kg over 7 days) * is a revised weight-based TQ regimen (TQRevised: target dose 7.5mg/kg) superior to fixed dose tafenoquine (300mg) * is the tolerability and safety of TQRevised acceptable * is TQRevised acceptable and feasible Participants will receive a tafenoquine target dose 7.5mg/kg in weight bands. Researchers will compare this to patients receiving a fixed dose tafenoquine and high dose primaquine to see if safe and effective.