 This is a prospective, open-label, multicenter, non-comparative, single arm study of pediatric subjects with Plasmodium vivax P. vivax malaria, aged 6 months to 16 years of age. A total of 60 subjects will be enrolled. Potential subjects who are slide-positive for P. vivax will be started by the site on chloroquine CQ per localnational guidelines. Sites will have up to 48 hours to obtain consent. Once full consent is provided, all subjects will be screened and, if eligible, receive Tafenoquine TQ, given as a single dose on Day 1. All study medication should be taken with food. After the treatment period, subjects will attend up to 7 follow-up visits through Day 120 Days 3, 8, 15, 29, 60, 90 and 120. The main cohort will consist of subjects aged 2 years to 16 years with no restriction on gender. Subjects will be dosed according to four weight bands. Within the total of 60 enrolled pediatric subjects, a second cohort of up to 6 infants aged 6 months to 2 years weighing 5 kilogram kg will be recruited following completion of a planned first interim analysis. An interim analysis will be conducted once sufficient data from 16 subjects is available to assess pharmacokinetic PK and safety parameters. If needed, a second interim analysis will be conducted after a total of 32 subjects have enrolled. The primary objective of this PK bridging study is to adequately characterize the systemic TQ exposure in the pediatric population. 