The Loss of our Sense of Smell and Taste from COVID-19 May Soon be a Thing of the Past

In Japan, a new antiviral pill is helping COVID-19 sufferers to regain their sense of smell and taste. This was a problem for those who were infected in the virus’s first wave. When the Omicron variant became the most dominant strain, the symptomatic loss of sense of smell diminished. In the current COVID-19 XBB variants, the loss is even less.

But for those who were first infected in 2020 through 2021, between 40 and 50% with COVID-19 experienced loss of smell and taste which made food unpalatable. I never lost my sense of smell when I caught COVID-19 in 2020, but the painter we hired to do our Toronto apartment the next year described his experience stating everything tasted rotten to him. He described food as having a gun-metal smell. The only benefit, he stated, was he lost a lot of weight because food became so unappealing. He still hadn’t fully recovered his sense of taste when we met him.

Xocova which also goes by the name Ensitrelvir Fumaric Acid, was approved in Japan last November. It is administered in pill form and given once daily for five days. The drug suppresses viral replication by inhibiting 3CL protease, an enzyme that breaks down the proteins produced by the virus. In clinical trials in Japan, the drug has produced no serious adverse effects and more notably, has helped restore the sense of smell and taste of those infected rather quickly. By the third day of treatment, clinical trials report the loss of smell and taste to be diminished, and by day seven, the restoration is quite dramatic. In addition, Xocova shortens the duration of other COVID-19 symptoms including the most severe that would lead to hospitalization and death.

Stated Yohei Doi, an infectious disease researcher at Fujita Health University in Japan, notes that the recovery of these senses comes back over time, “But we know that some people have had long-term issues with smell and taste.” 

That certainly has been the case in North America. A Harvard University study in the United States looked at almost 30,000 COVID-19 cases in 2021. That year 35.8 million Americans, representing 14% of the adult population of the country, got COVID-19. Of those 60% reported a loss of taste and smell. The severity of other COVID symptoms appeared to increase the duration of sensory loss.

Following the infection, 24% reported only partial recovery of their sense of smell, with 3% showing no recovery at all. The Harvard research estimates that 28 million Americans are still suffering from partial loss of sense of smell and taste from COVID-19 while 6 million have never got these senses back.

Xocova has yet to be approved for use in North America where Paxlovid remains the preferred pill for shortening the duration of COVID-19 infections in people who are most at risk. But Paxlovid hasn’t shown that it does much to restore the sense of smell and taste in patients who take it.

Laryngologists have had some success using a combination of fluticasone, a nasal spray and triamcinolone dental paste, noting significant improvement in smell and taste over a five-day course of treatment.

When Xocova comes to North America, you may find it under the Ensitrelvir name.