COVID-19 Symptoms Milder, Limited To Upper Respiratory Tract In Patients With Prior Immunity, Study Finds

Infectious Disease Advisor (6/13, Basilio) reported a study found that “prior immunity at the time of COVID-19 infection and Omicron predominance have contributed to reduced disease severity over time and are associated with greater odds of mild symptoms limited to the upper respiratory tract.” Researchers observed that “in patients who developed COVID-19 infection during the Omicron period, 8.0% had no prior immunity, 11.7% had infection-induced immunity, 61.9% had vaccine-induced immunity, and 18.3% had hybrid immunity. Compared with those with no prior immunity, patients with any type of immunity reported significantly lower rates of loss of taste or smell, constitutional symptoms, and gastrointestinal symptoms.” Furthermore, “study patients with infection- or vaccine-induced immunity reported significantly lower rates of lower respiratory tract symptoms than those with no prior immunity. In contrast, patients with no prior immunity reported lower rates of upper respiratory tract symptoms than those with any type of immunity.” The study was published in Open Forum Infectious Diseases.