A cohort study showed that patients with acute mpox clade II infection had persistent physical, behavioral, and psychosocial side effects more than a year after illness. The study included 154 people with mpox clade II infection. Among them, 58% had persistent side effects. These effects included physical symptoms, behavioral changes and psychosocial problems. Side effects persisted for more than a year after the acute phase of infection. The study suggests the need for long-term follow-up of mpox patients.