“…Patients were enrolled from five hospitals: Dhaka Shishu Hospital in Dhaka, Bangladesh; Kathmandu Medical College and Teaching Hospital (KMC) in Kathmandu and Dhulikhel Hospital, Kathmandu University Hospital (DH) in Kavre District, Nepal; and Aga Khan University Hospital (AKU) and Kharadar General Hospital (KGH) in Karachi, Pakistan; and a network of laboratory facilities in all three countries between 2016 and 2021. During the enrollment visit, information on demographics, symptom history and typhoid vaccination status were collected using a structured questionnaire; SEAP enrollment criteria and methods are detailed elsewhere (17). For prospective cases, we collected plasma at SEAP enrollment and capillary blood collected on filter paper (i.e., dried blood spot; DBS) at 28 days, 3, 6, 12, and 18 months post-enrollment.…”