Recurrence of Symptoms Following a 2-Day Symptom Free Period in Patients With COVID-19

(JAMA) Recurrence of symptoms after finishing treatment for COVID-19 with nirmatrelvir-ritonavir (Paxlovid) has become increasingly recognized.^1–3 The biological underpinning of this phenomenon is unclear, and its etiology may be multifactorial, including rapid clearance of nirmatrelvir coupled with delayed immune responses or possible development of drug resistance.^1–3 The contribution of treatment to symptom rebound needs to be differentiated from symptom rebound that might occur during the natural history of COVID-19. In this cohort study, we sought to determine how often COVID-19 symptoms recurred when the disease was untreated.