Alterations in smell or taste in individuals infected with SARS-CoV-2 during periods of Omicron variant dominance.

OBJECTIVES: To characterize the prevalence, severity, correlation with initial symptoms, and role of vaccination in patients with coronavirus disease (COVID-19) with smell or taste alterations (STAs). METHODS: We conducted an observational study of patients infected with severe acute respiratory disease coronavirus 2 (SARS-CoV-2) Omicron admitted to three hospitals between May 17 and June 16, 2022. The olfactory and gustatory functions were evaluated using the Taste and Smell Survey (TSS) and the numerical visual analog scale (VAS) at two timepoints. RESULTS: The T1 and T2 timepoint assessments were completed by 688 and 385 participants, respectively. The prevalence of STAs at two timepoints was 41.3% vs 42.6%. Furthermore, no difference existed in the severity distribution of TSS, smell, or taste VAS scores between the groups. Patients with initial symptoms of headache (P=0.03) and muscle pain (P=0.04) were more likely to develop STAs, while higher education, three-dose vaccination, no symptoms yet, or initial symptoms of cough, throat discomfort, and fever demonstrated protective effects, and the results were statistically significant. CONCLUSIONS: The prevalence of STAs did not decrease significantly during the Omicron dominance, but the severity was reduced, and vaccination demonstrated a protective effect. Additionally, the findings suggest that the presence of STAs is likely to be an important indicator of viral invasion of the nervous system.