Susan Desmond-Hellmann has a unique set of experiences. Until February, she was the CEO of the Bill & Melinda Gates Foundation, where part of her job was thinking up new ways to battle infectious disease. Before that, she was the chancellor of the University of California, San Francisco. In the 2000s, she was one of the most prominent people in the pharmaceutical industry, running drug development at Genentech during its time as one of the most closely watched biotechnology companies. That made her a perfect person to speak to about the risks posed by the novel coronavirus that causes Covid-19. STAT caught up with her earlier this week. The transcript below has been lightly edited for length and clarity.

My first question about Covid-19 is simple: How worried are you?

I’m very worried. I’m very worried for a couple of reasons. With pandemic preparedness, a respiratory-borne illness was always the big worry. And here we are. The efficiency of the spread of Covid-19 has me worried. The fact that individuals who are infected may be mildly symptomatic or asymptomatic and yet transmit the virus makes normal procedures, like telling people to stay home if you’re ill, or taking someone’s temperature as they walk through the airport, ineffective. That puts testing and, really, labor-intensive public health at a premium.

Can we still control community spread at this point? 

I’m not confident that we know the answer to that yet. I think the next several weeks will be very important. But I think it is very reasonable to be concerned that in fact we won’t be able to control community spread. We don’t enforce the kind of control measures that we’ve seen enforced in China.

How much do you trust the data coming from other countries on things like transmissibility and mortality?

I think the numbers should all be treated as estimates. It isn’t that I have a trust issue because of anything nefarious. But [data] have to be amended with the expectation that there are many, many mild or asymptomatic cases. And, so even when the number 2% mortality was widely discussed in my mind, I amended it to likely 1% or less.

I still have a big question about young people. Are kids somehow more immune, or are they just not at all getting sick? Are they transmitting the infection? But with regard to the high mortality rate in folks with underlying medical conditions, or who are over 60: Those numbers, I think, we need to believe.

What should people do now? We’ve had a really dramatic change in how people are reacting. What is prudent, and what is panic?

I think very simple public health measures are the best thing for the general public to do. The Centers for Disease Control and Prevention website offers steps that are very good: avoiding nonessential travel, especially to high-risk areas, hand-washing, serious hand washing, 20-second hand-washing. Or use those hand sanitizers, but I think people over-rely on hand sanitizers. Really good hand washing is very effective, you just don’t always have access to soap and water. Avoiding touching your face is very important.

If you are sick, call your health care provider. Don’t show up unless you’re very sick. Many workplaces are now banning nonessential travel, which I see as very reasonable. There’s a push to work from home. I also agree with the tenet that schools need to start to talk to parents about what they would do if they had to teach kids at home.

I’ll tell you personally, I’m not stocking up on groceries. And I’m not buying masks. I agree with the surgeon general that we should have masks available for health care providers.

At the Gates Foundation, you were involved in trying to set up a system for developing therapeutics in a pandemic. Where do you think we are with regard to therapeutics and vaccines?

I’m so glad that we invested in CEPI [the Coalition for Epidemic Preparedness Innovations], which is funding aggressive efforts in vaccines. I’m really grateful once again for multinational pharmaceutical companies who are racing to look at vaccines, antibodies, and therapeutics.

But there are two other things I would emphasize. We need to put more emphasis on diagnostics. Diagnostics are under-invested, they’re under-reimbursed and right now, the diagnostics are a bottleneck in public health measures. The second thing is we need to have funding for our local public health departments. This is classic basic shoe-leather epidemiology. And having an effective staffed funded public health department is essential.

The timelines for therapeutics and vaccines are very fast – therapeutics within a year, vaccines within two.  Does that sound realistic?

I think it’s reasonable. There needs to be human testing, especially for safety because many, many people won’t have a high mortality or even morbidity, which is why it’s not faster. And everyone wants it even faster. Look at Ebola. With Ebola, there was a very effective vaccine. It wasn’t ready the first time, but it was ready in the recent epidemic and, and made a big difference. In the meantime, therapeutics are also very important.

The high levels of mortality — as high as 15% — being seen in patients who are older than 60 is surprising.

Yes, I’m surprised how high it is. But as we get more cases, I think we’ll see whether or not that’s the truth. But there’s no doubt about it that over 60 — in some of the cases recently reported out of Washington state, people were in their fifties, but had additional medical conditions — have a very high spike in mortality rates.

There was recently a study of the genetics of the viruses in Washington state that indicated there could be hundreds of cases that went undetected there. How does that change your mental model of what’s happening?

That’s the kind of thing that the Gates Foundation has been doing with partners and collaborators for polio. It’s extremely helpful for disease tracking and understanding an epidemic. You have to make sure you remember that it’s modeling, not truth. But I found it incredibly compelling. What my mental model is moving to is when you have someone very, very sick who goes on a ventilator, that’s probably your evidence that you do have community spread, and there are many, many more cases than you’d think on the surface. Many more. Like hundreds of cases.

Do you have any closing thoughts?

It’s frightening for people to have an unknown virus. And it feels very scary. It is true that most people will be able to protect themselves and their families, and they’re not going to have something that makes them very, very sick. But really think about how sad it is for those people who did get sick and die, and their families. To think that you were in a nursing home, or somebody who was traveling and got sick … This is really sad. So I do hope we can ramp up the testing and get this thing under control. It’s always good to remember that there are people behind all this.

Matthew Herper is a senior writer, STAT News, where this article originally appeared.

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