Researchers are finally making headway in understanding how the SARS-CoV-2 coronavirus causes loss of smell. And a multitude of potential treatments to tackle the condition are undergoing clinical trials, including steroids and blood plasma.
Once a tell-tale sign of COVID-19, smell disruption is becoming less common as the virus evolves. “Our inboxes are not as flooded as they used to be,” says Valentina Parma, a psychologist at the Monell Chemical Senses Center in Philadelphia, Pennsylvania, who helped field desperate inquiries from patients throughout the first two years of the pandemic.
A study published last month1 surveyed 616,318 people in the United States who have had COVID-19. It found that, compared with those who had been infected with the original virus, people who had contracted the Alpha variant — the first variant of concern to arise — were 50% as likely to have chemosensory disruption. This probability fell to 44% for the later Delta variant, and to 17% for the latest variant, Omicron.