Partway through a conversation about simple solutions to prevent the spread of the coronavirus, a certain reporter caught himself, his hand flitting across his face with absent-minded determination.

A rub to the eye and a scratch to the nose before settling into a pose akin to Rodin’s “Thinker,” with chin in palm, fingers curled against the mouth. It’s a typical taxonomy of face touches, but it would make public health experts shudder — especially now.

That’s because this reporter just moved his hand over every place a respiratory infection — including the coronavirus — finds entree into the human body, all in less than a minute. If you have covid-19, the disease caused by the novel coronavirus, it began in your eyes, nose or mouth — your facial mucous membranes.

By now, most readers have seen the entreaties from agencies like the World Health Organization and Centers for Disease Control and Prevention: Wash your hands; don’t touch your face. It’s some of their simplest advice, yet it’s some of the most difficult to follow.

That’s not really our fault. We’ve been building the habits nearly all our lives.

“It’s very hard to change, because you don’t even know you’re doing it,” said William Sawyer, a family doctor in Sharonville, Ohio, and founder of Henry the Hand, a nonprofit organization that promotes hand hygiene. “It’s habit, and habits are hard to change."

Especially those as pervasive as face touching. A 2015 study found that we touch our face an average of two dozen times an hour, and 44 percent of that touching involves contact with eyes, nose or mouth.

Like all our habits, touching our face has been reinforced over time: It begins with an itch or an irritation, which feels better, temporarily, when scratched or rubbed. That reaction then becomes a tic, Sawyer said.

But passing unseen are the legions of germs living on your hands — picked up from your phone, keyboard, a doorknob or elsewhere — hitching a ride on the way to your throat, sinuses and lungs.

Not touching your facial mucous membranes, an area known as the “T-zone,” is perhaps the most important step you can take to prevent an infection, Sawyer said.

“It’s the one behavior that would be better than any vaccine ever created,” he said. “Just stop this simple behavior. Stop picking, licking, biting, rubbing — it’s the most effective way to prevent a pandemic.”

People are more likely to get the virus by picking it up from a surface and touching their face, than they are to breathe in droplets directly from someone who is infected, Sawyer said.

“They will give it to themselves, not the person down the hall,” he said.

Sawyer created Henry the Hand and its mascot, a T-shirt-clad yellow hand preaching hygiene awareness, in the 1990s when his children were in day care — “a petri dish” — but he began promoting it internationally after the outbreak of severe acute respiratory syndrome (SARS) in 2002.

The simple, one-two punch of hand washing and avoiding the T-zone can be empowering, Sawyer argued, because it’s an achievable solution to a problem that feels more urgent with each headline.

“Good health and wellness is in their hands,” he said.

But identifying the problem is just the first step. And the easiest. Next, you have to try to break the habit.

“Habit change is very, very difficult,” said Elliot Berkman, a psychology professor at the University of Oregon who studies habits and behaviors. “We’re designed to build habits. When you try to break habits, you’re working upstream against your own evolutionary history.”

It’s not enough to simply instruct people to stop, Berkman said; people must be able to “outsmart their habit” or form a different one. One way to do that quickly is to change something in your environment, he said. Wear something on your hands or face (just not a mask if you’re not sick) that can serve as a cue, an interruption to an automatic action.

Habitual smokers will sometimes alter their packs of cigarettes, so when they reach for one, something will call attention to their reflexive behavior, Berkman said.

“The practical thing is to assume you’re going to touch your face and try to change something else,” he said. “Something that, when you touch it, it reminds you of what you’re supposed to be doing. It draws your attention to the thing you’re trying to change.”

If you need to scratch your face, Sawyer said, cover your finger with a tissue first. It’s the bare hand you should avoid, he said, but gloves are no panacea, either, as they can also carry germs.

The 2015 face-touching study observed a class of medical students at the University of New South Wales, recording how often they touched their face during an hour-long lecture. It’s an experiment Sawyer has informally replicated in meetings and at conferences, observing even the most seasoned public health experts fidgeting with their T-zones.

It’s then he introduces them to “Henry the Hand,” he said: “A very simple solution to a complex problem.”