How Bad Is the Coronavirus?

And What You Can Do to Curb Its Spread

Tomas Pueyo
14 min readMar 1, 2020


Updated as of 3/1/2020

The world is slowly realizing the true dimension of the coronavirus, but it’s reacting slowly. Here’s a summary of everything we know that’s relevant and what we can do to protect ourselves and our communities.

How Bad Is the Coronavirus?

The two key numbers for an epidemic is how likely you are to get it and how bad it is when you do. These numbers are called the transmission rate and the death rate.

Let’s take a virus we all know: the flu. Its transmission rate (R0) is between 2 and 3, meaning that every person infects between 2 and 3 other people. They do that quickly: in only 2.6 days.

Its death rate is 0.13%, meaning that 0.13% of people with symptoms (1 in 770) dies.

How do these numbers compare with the coronavirus, and with other viruses like the one that caused the 1918 pandemic?

  • The transmission rate of the coronavirus is between 2 to 3 (number of newly infected per case, called R0), same as the flu, and higher than that of the 1918 pandemic: 1.4 to 2.8.
  • The mortality rate of the coronavirus is between 2% and 7% (2–7% of people who contract it die), compared to 10% for the 1918 pandemic, and 0.13% for the normal flu.

The reason for the death rate of the coronavirus between 2% and 7% is that it’s growing extremely fast. 2% of all cases have died, but that figure is 7% for closed cases.

Put in another way:

  • The coronavirus is between 15 and 50 times deadlier than the normal flu, which kills 60,000 people every year just in the US. If the coronavirus spreads the same way and maintains its death rate, it will kill between 1 million and 3.3 million people, or up to 57 Vietnam wars, just in the US.
  • The coronavirus spreads faster than the 1918 flu, and is between 30% and 80% less deadly. That pandemic infected 500 million people and killed ~50 million. For the entire world, that might mean the coronavirus might kill between 25 million and 92 million people, or about the same as World War II.

What Is the Situation today?


The Coronavirus started as a Chinese virus. Over 80,000 people are reported to be infected, and nearly 3,000 have died as of March 1st 2020. 25 out of 31 regions have been affected, but 96% of these cases have been in the Hubei region (primary data).

Thanks to the country’s measures, the spread in China is slowing down.

The World Health Organization released an interesting report this week (2/24/2020). It shows their trust that the virus is truly in remission in China, with signals like beds that used to be full are now empty, and some of the lessons we’ve learned from the country’s measures.

First is the fact that you can beat this thing without a vaccine: just with a thorough work of Social Distancing, research and medical treatments. One data points stood out for me: They have 1800 teams of 5 people whose sole job is to track everybody who’s been in touch with an infected patient. It’s likely they’ve been able to quarantine most relevant people thanks to that.

This just illustrates the lengths at which the country has gone. Unfortunately, this is not what other countries are doing. Quoting from the report:

“China’s bold approach to contain the rapid spread has changed the course of a rapidly escalating and deadly epidemic. In the face of a previously unknown virus, China has rolled out perhaps the most ambitious, agile and aggressive disease containment effort in history. China’s uncompromising and rigorous use of non-pharmaceutical measures to contain transmission of the COVID-19 virus in multiple settings provides vital lessons for the global response.”

“Much of the global community is not yet ready, in mindset and materially, to implement the [same] measures. These are the only measures that are currently proven to interrupt or minimize transmission chains in humans. Fundamental to these measures is extremely proactive surveillance to immediately detect cases, very rapid diagnosis and immediate case isolation, rigorous tracking and quarantine of close contacts, and an exceptionally high degree of population understanding and acceptance of these measures.”

“Concerningly, global and national preparedness planning is often ambivalent about such interventions.”

That is bad, because now we’re in Phase II: this is a pandemic.

Rest of the World

We have now 3 great examples of virus containment: China, Japan and Singapore. All 3 have over 100 total cases and less than 5% daily growth. It’s doable.

Other countries, however, are not doing as well.

Italy and Iran are doing especially poorly. Italy has spread the virus to over 30 countries. The country is entering progressive lockdown, but not fast enough. Over 40 provinces have cases, and only 3 regions don’t. Yet only 11 municipalities have required a lockdown, with fewer than 50,000 people.

Italy, Iran and South Korea are struggling with a death rate/closed cases of over 30%: 3 in 10 cases that have been resolved have turned out to be deaths.

Meanwhile, the number of total cases has nearly doubled overnight in France, Spain, Norway, Iraq, Austria, Greece, Lebanon, Netherlands…

Community Spread

Community spread is a spread that can’t be tracked to anybody specific. This is catastrophic, because if you can track it back, it means you can quarantine everybody and keep the virus in check. With community spread, you can’t anymore: the virus is loose.

All the data indicates that it’s a fact already in many countries. We just haven’t realized it yet.

You might have noticed Germany and UK in the high growth countries. I think the number shows their diligence at identifying the cases, not the severity of the outbreak. It’s likely happening everywhere. They’re just better at finding the cases. That would also explain why most European countries, with some of the best healthcare systems in the world, are at the top of the charts. Everywhere we’re looking for the coronavirus, we’re finding it.

“It just tells us where there is testing, there are cases. … There is no such thing as a barrier containment to keep these out.” Michael Osterholm, University of Minnesota.

But the worst piece of news comes from the US (2/29/2020): The virus has likely been running wild for over six weeks undetected in the country.

The first US infected person, on Jan 20th in Washington State, carries the same unique genetic variant of the virus as another person who fell ill this week. These two people have never been in contact. The likelihood of this being a coincidence is ~3%.

That makes it very likely that the first spread it to the second through the community. If that’s the case, scientists believe between 300 and 500 people are likely to be infected in the area.

There was another case of community spread in Santa Clara county that same week. Germany has also seen community spread cases, and France is investigating a dozen cases with unknown sources.

These are likely not outlier cases, but rather just the first times we catch this happening. This is already a pandemic, we’ve just not realized it yet.

What Will Happen Next

If you take a step back, three alarming facts, together, forebode that the Chinese situation will happen in many other countries that are not as prepared:

  • It’s a pandemic, officially in over 68 countries as of 2/29/2020, and growing by dozens every week.
  • Community spread is happening in two of the most prepared countries, meaning it’s likely happening in most of them and they don’t know it yet.
  • The only countries that are curbing this (China, Singapore, Japan) have a strong Confucianist culture and governments. Populist governments, developing countries or Western individualistic democracies are unlikely to react as decisively.

We already know what happens next: It happened in China until they realized their mistake. Cases will keep happening more and more, authorities will try to contain it with escalating measures, until the outbreak is total and lockdowns are ordered.

China learned this the hard way. We have the gift of foresight. It’s time to act decisively.

But instead of forecasting what will likely unfurl, our authorities are acting day by day, scared of overreacting and hurting the economy. Political leaders are concerned about being the first ones to limit freedoms and look like fools. They think: Nobody will blame me if I make the same mistakes as every other country.

But we will, because they should know better, and they don’t.

What Should Countries Do?

What should they be doing? Locking out the biggest virus hubs, to protect communities from outside, and encouraging Social Distancing, to protect them from inside.

To lock out virus hubs, they should immediately ban travel to hub countries. Yesterday, travel from Iran to US was still allowed. Today, it’s banned. But it’s still allowed to Italy or South Korea. Why? It’s a matter of time. They should pre-empt the spread and lock out many more countries immediately, adding more as cases are discovered. This is definitely a case of Better Safe than Sorry.

Social Distancing is meant to slash the virality within a community. It entails measures such as banning events with crowds or , banning or limiting mass transit, or even house confinement. Paris cancelled their marathon this Sunday (good) and France banned events with more than 5,000 people (bad: that’s still too big).

These measures will start happening everywhere. It’s a matter of whether governments will do them pre-emptively or after outbreaks.

What Can You Do to Protect Yourself and Your Family?

This begs the question: What can you do about it? How can you remain safe? If there’s one thing you should remember, it’s this:

Don’t touch your hands with dirty hands.

Here are more details on everything we know:

Who Is Impacted?

1. For some weird reason that nobody knows, there’s not a single death of a kid below 10 years old. If you have young children, you can probably breathe — unless the virus mutes.

2. More generally, if you’re young and healthy, it’s unlikely this will affect you. The older and sicker you are, the more danger you incur.

3. Women are also 40% less likely to die than men

How Does It Spread?

4. The scientific community speculates that this virus might behave similarly to other flu viruses, which suggests they tend to spread more easily in either [cold and dry] weather or [warm and humid]. So if you expect the warm weather to keep you safe, that’s only true if you live in a dry place. In places like San Francisco, warm weather should make it worse, not better.

5. But don’t run to switch on your humidifier. Contagions will likely happen outside of your home, so measures at home are unlikely to matter much anyways. The most important thing to protect your family is to disinfect yourself immediately after entering the home.

6. So how does the virus spread? Through aerosols and surfaces. Somebody coughs and you either catch the droplet in the air or from a surface.

7. The most accurate number I’ve seen is that it travels by air around 1.5m on average (~5 feet). That means that, as long as you keep your distance with people and avoid crowds, you should be good. Avoid shows or movies. Avoid public transport if possible. Avoid lines at the supermarket. Tell everybody you know to do the same. This is also the reason why schools, public events and mass transit are going to be the first to close. It’s also why health experts don’t recommend masks if you’re not contaminated: the likelihood that somebody coughs in your face is low (for the same reason, they don’t recommend protective glasses). The only exception is if you cough, to prevent others from catching it.

8. Conversely, it becomes much more important to not get infected through surfaces. Current research suggests the virus can survive for days on a surface. The key contagion mechanism you want to avoid is picking up the virus with your hands and placing it on your face. Consider all public surfaces potentially infected, especially metals, ceramics and plastics. Tables and doork nobs are probably some of the worst things to touch, since a lot of other people also touch them and they tend to be made of materials on which viruses like the coronavirus tend to survive for a long time. I like to imagine that every surface outside is soaked in red wet paint, and my goal is to not get any paint on my face. Cardboard (like your Amazon packages) should be fine, but you can always disinfect them with an alcohol spray.

9. This is why authorities recommend washing and disinfecting your hands constantly, and not touching your face with them. As long as the virus is on your hands, you’re good. If it penetrates your body through your nose, mouth or eyes, you have a problem.

10. It’s also the reason why they don’t recommend wearing gloves: you’re not trying to protect your hands, you’re trying to protect your face from your hands. With gloves, you are less likely to wash your hands frequently, picking up viruses on the gloves, and then transporting them to your face. Unless you’re willing to replace gloves more frequently than you wash or disinfect your hands, don’t use them.

11. Now you understand why the authorities think masks can’t be just a waste, but counter-productive: they don’t protect you much from the air, but they might make you more confident, not washing your hands as much, and when you go and take the mask off, you carry all the viruses to your face. Don’t do that. If you wear one, at least take your gloves off and wash your hands before taking the mast off.

12. The best way to disinfect your hands constantly is to carry disinfectant with you at all times and place it in conspicuous places.

What Can You Do to Help Curb the Coronavirus?

As I’ve shared this advice with friends over the last few days, they’ve forwarded my advice to their communities. It dawned on me that keeping ourselves safe is the most basic thing we can do, but there’s something much more impactful we can do: Nudging our communities in the right direction.

The best way to protect yourself is not, in fact, to just protect yourself. It’s to protect your community.

If everybody around us is getting infected, we will end up in home lockdowns for weeks or months, and thousands will die. But if we can slow down the progress in our communities, we have a good chance of slowing this thing down until there’s a vaccine.

Because, don’t get confused: This is now a race against a vaccine. The goal is not to emerge unscathed: It’s to slow down the virus as much as possible until your community can be safely vaccinated, so that there are as few casualties as possible until then. But it’s still between 12 and 18 months away.

So here’s what we can do as a community to slow the coronavirus down, and what you should help everybody around you do realize:

What Should You and Your Company Do?

Your company’s actions are the ones that will most determine the outcome for you and your family. Companies can do many things to protect you, but they don’t know what to do exactly.

This is so novel for everybody that HR departments are likely to be more overwhelmed than you are right now. They might not know exactly when to do what.

You should help them understand the danger and ask them to take the measures they need. Here are a few rules, as well as a few examples of big companies that are leading the way.

1. If you can work remotely, do it. If you can’t, but it would be possible, push your company to make it happen. Best case scenario, it will prevent an outbreak. Worst case scenario, the company will be ready if there is one. Ask your co-workers to do the same.

2. If you have to physically work in an office, keep a 1.5m (5 feet) distance with your co-workers. Limit meetings. When you have them, try to invite as few people as possible. Don’t sit close to each other.

3. If your work is public-facing, consider wearing a mask a gloves. Remember: both your gloves and masks might be contaminated. Before taking your mask off, take your gloves off and wash your hands. Wash them again after taking the mask off.

4. Ask that everybody stop shaking hands. It’s an outdated heritage from the Middle Ages anyway. Same thing for hugs with acquaintances. I propose a smile and a handwave instead.

5. Put a bottle of hand disinfectant in every room. Make it a habit to disinfect your hands every time you see one of these bottles. Encourage your company to put them in all rooms and on people’s desks.

6. Ask your company to stop all business travel. Including visitors. Ask it to recommend employees to avoid traveling for personal reasons. If they do travel, keep track of where they go. Have a black list of countries based on prevalence of the virus. If people come from these countries, your company should ask them to quarantine themselves home for 2 weeks.

7. If you feel unwell, stay home. If you have to leave home, don’t get close to people and wear a mask. If you don’t have one, cover your mouth with anything that can stop you from coughing out, such as scarves. If you cough and don’t have your mouth covered, cough on the inside of your elbow. It shouldn’t get to that.

Your company needs to package these and other recommendations into a plan with measures and triggers. You need both: the measures to know what to do, and the triggers to know when to start following these measures.

The best example of what to do is from Coinbase

Coinbase: They have an open google doc with measures and triggers. Their triggers are broadly 100, 1000, and 5000 cases of community infections. They trigger phases that go from suggested work from home and workplaces cleaning, to complete isolation and personnel extraction.

Amazon: friends tell me employees must defer all non-essential travel (both domestic and international). Essential travel needs VP approval.

Google: friends tell me all work trips in the US cancelled. Personal travel is not yet. I expect that to change very soon — or to require a quarantine after a trip. There is hand disinfectant everywhere at the Mountain View campus.

Nike: They’ve shut down the Portland campus completely.

Twitter: All events cancelled.

What Else Can You and Your Community Do?

10. It’s too early to close schools down, but they might soon. In the meantime, let’s slow down the spread there as much as possible. Give disinfectant liquid and wipes to teachers. Ask them to constantly clean the kids’ hands and classroom surfaces. Share this advice with your school administrators and teachers.

11. Tell your politicians to act. Send them this note, call them, email them, whatever you need to do. Translate it into your language and share it widely. The more people share the alarming data and talk with them, the earlier they will act.

12. Spread this message—or any equivalent, like this one from Elad Gil—with everybody you know. Remember: Your goal is not to be protected forever from the virus. Your goal is to slow it down as much as you can until your community is vaccinated, within 12 to 18 months. If you think this can help, please share the message.



Tomas Pueyo

2 MSc in Engineering. Stanford MBA. Ex-Consultant. Creator of applications with >20M users. Currently leading a billion-dollar business @ Course Hero