(Bloomberg Opinion) -- About a month ago, I prepared for Covid-19, then just known as the coronavirus, by refilling  some essential heart medications I was worried might run out if there were serious supply chain disruptions. The pills were for my cat — I figured it was better to be safe than sorry. And now that coronavirus has spread to at least 48 countries, more and more people are confronting the question of how much preparation is enough, whether for themselves or those people and pets relying on them.

Experts have known for weeks that this disease was likely to spread around the world, though of course little is certain since this virus is so new. Risk communication expert Peter Sandman says the CDC should have emphasized earlier the need for individuals and companies to prepare. Now, suddenly, CDC is sounding alarms that should have been sounded long ago — but President Donald Trump isn’t helping matters by countering their warnings with vague reassurance.

The panic we’re seeing now is what Sandman calls an adjustment reaction. When something frightening comes along, he says, people tend to overreact temporarily, and possibly become too paralyzed to take action. If people can get used to the problem, they are more prepared to act rationally.

There’s no need to be frightened, but it’s useful for people to prepare in a practical sense and an emotional one. Emotionally preparing means staying calm and ready for changes such as the cancellation of large events or requests to avoid public transportation.

Practical preparation can take many forms. Companies should be cross-training people, in case any essential employees become infected. Employees can gear up for the prospect of having to temporarily work from home. School closings are possible, and might cause more absenteeism. There are ways to plan ahead to minimize disruption if key people are too sick or too scared to come to work. And since people over 65 appear much more likely to die from this virus than younger people, it can’t hurt for all of us to check on older people we know and make sure they are safely supplied with their medications and food.

You may see lots of people — either in person or in media images — wearing masks, giving rise to the impression that this is the thing to do, but experts don’t advise healthy people to buy them. They say it’s far better to wash your hands. It sounds trivial, but lives might be spared if more people took the time to do it more thoroughly and more often. People should also watch the news and consider staying home if the disease spreads widely in their neighborhoods.

In the absence of a national hotline for people who feel symptoms to call (hint hint, President Trump), if you think you feel sick it would be better to call your doctor than show up at the emergency room. There’s a risk that people might overwhelm hospitals, with the infected spreading the disease to the worried well.

Experts disagree on whether to relax travel bans or start regional quarantines. Right now, a good precaution would be to keep an eye on the news, avoid travel to places with big outbreaks, and consider staying home from work if the disease breaks out in your city or town.

There’s still so much scientists don’t know for sure about this new disease — the incubation time, why it’s deadly in some cases and mild in others, why children seem to be less affected than adults, why the disease appears more fatal to men than women (even in experimental animals), and how many unknown cases are lurking. Scientists don’t know how much faster the disease would have spread without travel bans and quarantines in China. They aren’t sure whether it will subside in the summer as seasonal flu does, and they don’t yet know whether it will eventually burn itself out or settle into a seasonal pattern as happened with the pandemic flu outbreaks of 1917 and 1957.

Trump’s bluster about a vaccine wasn’t helpful. That’s likely to take months or even a year; people are worried about the near future. And even saying the “risk” is extremely low is vague. The risk that any given individual will die from this is low, but the risk that things will change is high.

So settle in for a long period of uncertainty. And if you (or your cat) needs an essential medication, best go out and get it now.

To contact the author of this story: Faye Flam at fflam1@bloomberg.net

To contact the editor responsible for this story: Sarah Green Carmichael at sgreencarmic@bloomberg.net

This column does not necessarily reflect the opinion of Bloomberg LP and its owners.

Faye Flam is a Bloomberg Opinion columnist. She has written for the Economist, the New York Times, the Washington Post, Psychology Today, Science and other publications. She has a degree in geophysics from the California Institute of Technology.

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