Peter Bergen is CNN's national security analyst, a vice president at New America, a professor of practice at Arizona State University. His new book is "Trump and His Generals: The Cost of Chaos." The opinions expressed in this commentary are his own. View more opinion articles at CNN.

(CNN) Michael Osterholm, the infectious disease expert who has been warning for a decade and a half that the world will face a pandemic, says the US is ill-prepared to combat the coronavirus due to a shortage of equipment and supplies.

Osterholm, of the University of Minnesota, wrote in Foreign Affairs magazine in 2005 that, "This is a critical point in our history. Time is running out to prepare for the next pandemic. We must act now with decisiveness and purpose." He reiterated this point in his 2017 book, "Deadliest Enemy: Our War Against Killer Germs."

Osterholm discussed the coronavirus at a recent Washington, DC event at the New America think tank with Peter Bergen, CNN national security analyst and New America vice president.

He took issue with the idea that the flu is a more serious threat, saying the death toll from coronavirus could be much higher than that of a severe flu season. Osterholm said there's very little vacant capacity in the health care system to fully deal with the effects of the coronavirus. And he pointed out that there's a shortage of protective clothing for health care workers.

Osterholm also discussed the impact that widespread obesity might have on that fatality rate; the lack of much-needed ventilators and respirators at hospitals; the ubiquity of the virus and what that means for overseas travel, and he poured much cold water on the notion that this coronavirus might disappear as the weather warms. The discussion was edited for length and clarity.

BERGEN: Have there been any changes in the US since you warned three years ago of the failure to prepare for the next pandemic?

OSTERHOLM: We are worse off today than we were in 2017 because the health care system is stretched thinner now than ever. There is no excess capacity. And public health funding has been cut under this administration.

BERGEN: How deadly is the virus? What do you think the case fatality rate is? Is there an approximation?

OSTERHOLM: We know from the Chinese data that being a male, older and having underlying health conditions are risk factors for We know from the Chinese data that being a male, older and having underlying health conditions are risk factors for increased serious illness and deaths

For older men in China, smoking is still very common -- 60% of older males smoke.

Smoking likely played a big role in the increased risk of this demographic dying from coronavirus. We see the same trend with influenza in our own country.

Of note, only a small percentage of older women in China smoke, meaning they were much less at risk for serious disease.

We're concerned about the occurrence of other risk factors for severe disease as this virus moves out into other parts of the world. For example, one of the risk factors for acute respiratory distress syndrome, or ARDS -- the most severe of the outcomes of COVID-19 infection -- is obesity. In parts of the world, including the US, where obesity is an epidemic problem, its likely we may see a different case fatality rate than we're seeing in China; that is, US fatalities may be less gender-specific and the rate of fatalities could be even higher than it is in China due to higher obesity rates among people 45 years or older.

According to the World Health Organization (WHO), the case fatality rate in China to date is 3% to 4%. However, WHO has estimated it to be as low as 0.7% outside of Wuhan, the epicenter of the outbreak.

In the US -- and in other upper and middle-income countries -- we may expect to see a case fatality rate equal to or higher to what we see in China.

BERGEN: So, if in a regular year in the US, the case fatality rate of influenza is 0.1%, you're saying that COVID-19 will be higher?

OSTERHOLM: Twenty to 30 times higher. It could easily be that. We just don't know yet and it could go down based on what we learn.

BERGEN: So, if the 0.1% case fatality rate of the flu kills tens of thousands in any given year in the US, what are the implications for the coronavirus?

OSTERHOLM: It's obvious that this is a very serious challenge. I think that it was unfortunate that a number of public health professionals said early on when COVID-19 first emerged that annual influenza was a much It's obvious that this is a very serious challenge. I think that it was unfortunate that a number of public health professionals said early on when COVID-19 first emerged that annual influenza was a much more serious problem

What they hadn't understood was that they were only watching the opening scene of this particular "coronavirus winter," as I call it. We can expect to see a large number of deaths moving forward -- far surpassing any severe influenza season.

The Chinese data suggests that anywhere from 5% to 10% of COVID-19 cases will become severe illnesses. These cases require a tremendous amount of expert health care; that makes this disease even more of a challenge relative to influenza.

BERGEN: Are we equipped with the ICUs and the ventilators to deal with a large-scale group of people coming in with these kinds of symptoms?

OSTERHOLM: Absolutely not. Right now, today, in Minneapolis-St. Paul, every one of the beds that we use for extracorporeal membrane oxygenation (ECMO), a high-level machine that supports the heart and lungs and is critical for keeping people alive who have illness like COVID-19, are filled. This is in part because we are just coming off a moderate to severe flu season and that has really stretched our care capacity. On top of that, a number of hospitals throughout the country have only 5 to 10 days' worth of personal protective equipment (PPE) available for health care workers. They don't know when over-stretched PPE manufacturers will be able to deliver more.

BERGEN: What can be done?

OSTERHOLM: First of all, we have to utilize the health services we have in different ways, meaning we will need to stop elective surgeries. Anybody who is not severely ill with other conditions will not be hospitalized. We need to be preparing our pandemic plan and must be thinking through what we would do if we had a 20% to 30% jump in the number of hospitalizations.

Remember, in Wuhan we had a number of people who were desperately ill, needed hospital care and couldn't get into a hospital. Many people were dying at home, not in the hospitals.

The next question is: how are we going to protect our health care workers? We need solutions that are not ideal but that may work. We need to open up wards where everyone in the ward is infected, rather than having one patient per room, meaning that health care workers must each put on and take off their PPE an average of 20 to 25 times a day. With multiple patients in a room, health care workers could potentially use the same protective equipment for much of a shift.

So, there are things we can do, but we still have a very high likelihood that we're going to face major PPE shortages. We simply don't have good answers for that right now. We'll likely have to revert back to the use of more available surgical masks in contrast to N95 respirators, which are the preferred PPE to prevent the spread of the virus between patients and health care personnel. Surgical masks, we know are largely ineffective in preventing virus transmission. Thousands of health care workers in China have become infected, many of those early in the outbreak when it wasn't completely understood just how infectious this virus is.

I believe that these cases are tied to the absence of adequate respiratory protection.

BERGEN: Are you saying that the N95 respirator is not available in any meaningful quantity?

OSTERHOLM: It's not. No health care organization has gone out and stockpiled lots of personal protective equipment. They have always bought it on a just-in-time basis. So now we're paying the price for that. (Editor's note: The US just It's not. No health care organization has gone out and stockpiled lots of personal protective equipment. They have always bought it on a just-in-time basis. So now we're paying the price for that. (Editor's note: The US just took action to make more N95 respirators available.)

When health care workers start dying or get severely ill and they go from being care providers to needing care -- and hospitals are not able to handle patients because of a reduced number of health care workers -- I think that's when you run the risk of people losing confidence in its government and leaders.

One thing I worry desperately about is this virus in long-term care. The current experience in the Seattle metro area with the number of infected long-term care facilities shows how devastating COVID-19 can be in this setting. If you take out most of the long-term care workers with infection and you have sick patients, who takes care of them? This is going to be a huge challenge.

BERGEN: Last week the FDA Commissioner Stephen Hahn promised that there would be Last week the FDA Commissioner Stephen Hahn promised that there would be 1 million coronavirus tests available by the end of the week -- but that was an unattainable goal in such a short timeframe.

What do you make of that?

OSTERHOLM: We're going to see most state health departments clearly having the capacity to test in all 50 States and at least 12 or 15 large city health departments in the near future.

But we didn't have the kind of testing here in this country that much of the rest of the world has enjoyed for at least four to five weeks.

BERGEN: Why was that?

OSTERHOLM: In short, the CDC had a problem with Plan A, in other words making a coronavirus test available for the US. And nobody at CDC had a Plan B, C, or D. This was a real failure.

What I think frustrated health professionals is that we knew we likely had widespread transmission ongoing. Unfortunately, this lack of testing reinforced the fantasy that we somehow had stopped transmission of the virus from coming into this country. What I have said many times over the past six weeks is all we really did was fix three of the five screen doors in our submarine. In fact, we knew that we had cases coming into the States despite the fact that restrictions on flying to or from China and airport temperature screening may have slowed down the rate of new infections. Containment of this virus and preventing it from getting into the US was never possible, despite what some government leaders proclaimed.

Look at the situation in Seattle. There was a case that was detected in January when upon return from China an individual became ill. This person was put in isolation, but not before he had been in the community. Nonetheless our response to this case this largely considered a great success in terms of stopping ongoing transmission. As we now know, at least one of the patients who was tested in Seattle, another individual six weeks later, was infected with the same strain. It's likely that original virus introduction into the Seattle area did occur with this January case, meaning that there had to be at least six or seven generations of transmission between the time that the individual first arrived in the United States from China back in January and this new case. So, we've had ongoing transmission in this country for weeks.

BERGEN: We've had other coronaviruses like SARS and MERS, which, although highly problematic, didn't really kill very many people, relatively speaking. What's the difference between this coronavirus and those coronaviruses?

OSTERHOLM: This is a very, very different coronavirus. Think of this as an influenza pandemic caused by a coronavirus and you're thinking about this in the right way.

SARS had close to 10% case fatality rate. MERS has a case fatality rate of 25% to 35%. The COVID-19 virus has a case fatality rate that is somewhere between seasonal flu in a bad year, which is 0.1% , and the 1918 pandemic, which, of course, preferentially killed young adults with a case fatality rate of 2.5% to 3% . So this is clearly in that range of what would be considered a severe influenza pandemic if this were the influenza virus.

When we think about infectious disease transmission, we refer to the concept of RO (a term that indicates how contagious an infectious disease is) or how many people on average an individual transmits the virus to. And what we see with coronavirus is it's probably about an RO of 2 to 2.5. It's surely dynamic. If we consider regular influenza, it's about 1.4. If you think about pandemic influenza, it tends to be about 1.8 people. So, this is quite different.

What's different here is the fact that in the cases of SARS and MERS -- and I was very involved with both outbreak investigations -- patients were most infectious on day 5 or later, and it allowed us the opportunity to identify these patients early in their illness and get them into appropriate isolation. Here, virus transmission is occurring early in illness, likely even before symptoms show up. It is very similar to influenza.

BERGEN: How does this coronavirus pandemic unfold?

OSTERHOLM: Well this outbreak from our perspective has really unfolded on time, and what I mean by that is even in the second week of January, it was very clear that this was no longer going to be a MERS- or a SARS-like situation with transmission only later in the illness. It was much more dynamic. Clearly, it was acting very much like an influenza virus; we were not going to be able to control it. This is influenza-like transmission, and it's going to continue for some time to come.

So, the fact that we went from 26 countries with cases of the virus 14 days ago to over 80 countries with cases now shouldn't surprise us. An extraordinary amount of new transmission is occurring everyday all over the world.

In our country there is widespread transmission going on now. It's just being missed, and as soon as we have testing, we're going to see it.

Let me make one point really clear; which I think has not received sufficient discussion. We keep hearing that this is going to die out with the spring warmer weather in the Northern Hemisphere. SARS ended in 2003 in June, but it had nothing to do with the seasons at all. It took until June of 2003 to understand how to stop transmission and then carry out our prevention activities. This had nothing to do with the seasonality of SARS. I've investigated outbreaks of MERS on the Arabian Peninsula when it was 110 degrees.

The other thing that seems to support the conclusion that there will be seasonality with COVID-19 is the seasonal nature of influenza. In fact, while there is seasonal influenza in the two hemispheres, it occurs year-round in the tropics. And of the last 10 influenza pandemics, two started in the winter, three in the spring, two in the summer and three in the fall. We have no evidence from what we know about influenza to suggest that COVID-19 will subside with summer in the Northern Hemisphere.

So, is it going to be like the typical seasonal flu year where 8% to 15% of the population gets infected? We don't know. It could be a lot more. One model from the Harvard School of Public Health, the model I find most reliable, estimates that, at minimum, 20% of the world's population will get infected.

That's why even when we talk about the case fatality rate, it's important to remember that if there's a disease that has a very high rate but only 100 people get it every year, that's not nearly of the same public health significance as a disease that has a low case fatality rate of 1%, but a billion people get it.

AUDIENCE QUESTION: Is closing down schools or businesses for a period of time an effective measure to control the spread of the virus, and if so, what would be the optimal length of time for these to be closed?

OSTERHOLM: We need to start to normalize our response to this, and what I mean is that we have to be thoughtful, and we can't just knee-jerk. Right now, we've all been struck by the relative absence of cases in kids in China -- We need to start to normalize our response to this, and what I mean is that we have to be thoughtful, and we can't just knee-jerk. Right now, we've all been struck by the relative absence of cases in kids in China -- 2.1% of cases are 19 years of age or younger.

I'm all for closing schools if we show that kids are important transmitters of the virus, but school closings have tremendous negative impact on communities. And they often disproportionately affect lower socioeconomic status individuals. If parents have to stay home with their kids, then some don't get paid. So, one of the things that we don't want to do is react without data.

For businesses, this is one area where it's a major challenge. We've got to keep the lights on. We've got to keep food coming, and we've got to keep really critical drugs coming. I hope we can keep businesses running as much as possible.

I think quarantining people coming back from high-risk countries today is largely unproductive. I say this knowing I'm probably not in the majority voice and this idea is surely not popular. Based on this approach, you could just as easily make the case that we should be quarantining or issuing a travel alert to King and Snohomish Counties (in Washington State) as we do for China, Iran, Korea and Italy. We've got a lot of virus transmission around the world right now. How many places can you cordon off before you finally say: "Oh well, you know, we're all walled off here in the United States, and we're just as bad."

We need to start normalizing our COVID-19 response. Don't prevent air travel; there's just as many people likely in this country that are going to pose a risk as people coming back from abroad. That's the kind of thinking we need to start having now.

I do have concern about that some people are highly reliant right now on the use of face mask (i.e. surgical mask) protection and think that's going to reduce transmission. It is not. We are urging that all N95s respirators be used by health care workers or critical infrastructure workers only, not for the general public.

AUDIENCE QUESTION: I have travel plans to Indonesia and the Philippines in a few weeks, should I go?

OSTERHOLM: Assume this virus is everywhere. This is a global influenza pandemic caused by a coronavirus.

The President was not lying when he got up in front of the country and described the small number of cases we had confirmed. That was true, but did it reflect the reality of what was happening? Absolutely not. Many countries around the world may have some of the same problems of testing and may be unaware of the scope of the virus. So, I would just assume it's everywhere.

Anybody who has ever been to Jakarta, Indonesia knows there are a lot of people there. You're going to likely increase the chances of being exposed and getting infected with this increased number of contacts. What will you do if you need hospitalization? Do you want to be hospitalized in Indonesia?

Now, I would tell you, if you have a chance to go on a cruise ship right now, I'd bypass that one. Cruise ships have been notoriously a problem with respiratory-transmitted agents because of all the recirculated air that occurs in the inside cabins. I would have told you that well before the Diamond Princess happened.

If you do travel internationally, I don't think that it'll put you at a much higher risk than flying domestically in the US. But do you want to get hospitalized in Country X and do you know that you can get back into the United States without a 14-day quarantine? These are questions that make me hesitant to do international travel right now.

AUDIENCE QUESTION: There are a whole lot of people in this country who don't have paid sick time, and I'm wondering what there is that we can do in the short term to encourage those people to actually not come to work if they are sick?

OSTERHOLM: Every workplace setting today should be discussing this right now with their employees. Tell them what we know about COVID-19. Tell them what we're going to do when our first coworker is infected. The more information you can give to employees the more responsibly they will respond when the case numbers begin to climb. If remote working is possible, tell employees do it, but help them understand one critical prevention point: If you work remotely for 70% of the day but then you spend the night out at a restaurant or in large crowds, you've minimized all that you did during the day to protect yourself.

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There are some who have said that this virus is only transmitted from the hand to the face and that's simply not true. We have compelling data on influenza transmission, which this is just like the coronavirus in terms of ongoing transmission. And, frankly, hand washing may play some role in this, but not nearly as much as people think. It's all about the air and the air you're breathing