Decreasing Incidence of Chemosensory Changes by COVID-19 Variant.

Anecdotal clinical observation suggests that rates of chemosensory dysfunction associated with COVID-19 infection may be decreasing. To investigate, the National COVID Cohort Collaborative database was queried for all patients with and without smell and taste loss within 2 weeks of COVID-19 diagnosis. Six-week periods of peak variant prevalence were selected by using CoVariants.org for analysis. Of 3,678,214 patients with COVID-19 in the database, 616,318 met inclusion criteria during the time intervals of interest, with 3431 having an associated smell or taste disturbance diagnosis. With the initial/untyped variant set as the baseline, the odds ratios for alpha, delta, and omicron (December 27, 2021-February 7, 2022) were 0.50 (95% CI, 0.45-0.55; P < .0001), 0.44 (95% CI, 0.41-0.48; P < .0001), and 0.17 (95% CI, 0.15-0.18; P < .0001), respectively. These data strongly support the clinical observation that patients infected with more recent variants are at a significantly lower risk of developing associated chemosensory loss.