Sofosbuvir as post-exposure prophylaxis for yellow fever–associated viscerotropic disease (YEL-AVD)

Abstract Objectives Yellow fever–associated viscerotropic disease (YEL-AVD) is a rare but serious complication arising from administration of live-attenuated yellow fever vaccine to individuals with risk factors such as thymectomy. At present there is no evidence-based treatment, and case fatality rates are high. Sofosbuvir, an NS5B nucleotide inhibitor, has activity against yellow fever virus in vitro and in vivo. Patient and methods Here we describe clinical and virological response to use of off-licence sofosbuvir as post-exposure prophylaxis for a patient inadvertently given yellow fever vaccine despite previous thymectomy. Results A 14-day course of oral sofosbuvir was administered in an outpatient setting with regular clinical and biochemical monitoring. The patient remained well without developing clinical features of YEL-AVD and did not experience adverse effects from the treatment. Conclusions This supports the use of sofosbuvir as post-exposure prophylaxis in patients at high risk of developing YEL-AVD. Ongoing trials of efficacy of sofosbuvir in yellow fever infection may result in stronger support for this approach in the future.