SCIENCE & TECH: Stick of gum could soon detect the flu — how it works

It’s about thyme!

The flu is one of the most common and contagious diseases — it causes up to 41 million illnesses, 710,000 hospitalizations and 52,000 deaths each year in the US, according to the Centers for Disease Control and Prevention.

It’s often diagnosed with a nasal or throat swab that’s tested for the presence of influenza viruses. Until recently, though, over-the-counter flu tests weren’t available in the US.

Soon enough, you may not need to swab at all. German chemists say they have developed a sensor that releases a thyme flavor when it comes in contact with the flu virus. Eventually, they hope to tuck the sensor into a stick of gum or lozenge.

“There is an urgent need for readily manufacturable, easily supplied and straightforward first-line
defense tools,” the researchers wrote Wednesday in the journal ACS Central Science.

“These tools could quickly help identify individuals at risk of carrying influenza so that they can be
moved into quarantine.”

The Food and Drug Administration (FDA) has historically been cautious about at-home diagnostic tests, including those for the flu, due to concerns about their accuracy and the potential for user error.

The first OTC flu test was the Lucira COVID-19 & Flu Home Test, which was granted emergency authorization by the FDA in 2023.

The FDA authorized the Healgen Rapid Check COVID-19/Flu A&B Antigen Test last year, making it the first at-home test to receive approval outside of emergency use.

The lack of convenient and comprehensive flu test options inspired the molecular sensor.

“[We] set out to create a flu-testing framework that is rapidly accessible, cheap to produce, easy to distribute and responsive in the early phases of infection as a prerequisite for global use,” the researchers wrote.

“We solved this challenge by switching away from complex detectors and machinery and toward a detector that is available for anyone, everywhere and anytime: the tongue.”

The sensor would revolutionize the diagnostics market.

Here’s how it works: Neuraminidase is found on the surface of flu viruses.

The viruses use the enzyme to cut certain chemical bonds so they can spread from infected cells to healthy cells.

Scientists made a synthetic molecule that mimics the natural target of neuraminidase and attached thymol, which is responsible for thyme’s distinctive taste and smell.

The flu virus’s neuraminidase recognizes the fake molecule and cuts it, releasing the thymol. The tongue detects the flavor which has a sort of herbal but medicinal taste.

The researchers noted that their sensor is “chemically tuned” to respond to viral but not bacterial neuraminidase, meaning that the test won’t give a false positive if bacteria are present in saliva.

In human saliva tests, the sensor released thymol within 30 minutes.

The researchers hope to start trials in two years to test the sensor in flu patients before and after symptoms emerge.

In the meantime, the flu vaccine is recommended for everyone 6 months and older, with rare exceptions. The shot trains the immune system to recognize and combat the flu virus, which helps prevent illness or reduce its severity.

Flu season tends to peak between December and February as people spend more time indoors. The cold, dry conditions allow the viruses to spread more effectively.

If you contract the flu, experts strongly advise staying home so you don’t infect others.