Coronavirus: 7 insights from Yale epidemiologist

Just as quickly as the coronavirus outbreak spreads, so does misinformation about the virus. Dr. Kaveh Khoshnood, a professor of epidemiology at Yale School of Public Health, gives the full picture on how the outbreak will end, the impact of warm weather on the virus, if the virus will return next year, and more.

Here are Dr. Khoshnood’s answers to seven coronavirus questions:

Q: When will the COVID-19 outbreak end?

We can’t come up with an exact timeline for when the outbreak will end. But for a pandemic to die down, the majority of the population needs to develop protection against the virus - through either exposure to it or with a vaccine.

Given that this is a new virus, everyone is susceptible since our bodies have not developed an immune response to it. The outbreak will end when there are not enough susceptible people for this virus to infect. The number of susceptible people to the virus needs to drop significantly to end this outbreak.

You become less susceptible, or more immune, to the virus in two ways: recovering from an actual infection, or if there is a vaccine available and you get vaccinated. It will likely take one to two years for a coronavirus vaccine to be on the market.

Q: What is unique about this virus?

This virus has a higher infection rate than the seasonal flu. One person with this virus on average infects two to three other people. Secondly, you can have this virus showing no symptoms and being infectious. That is a factor that is very different than SARS. With the coronavirus, you could be walking around with no symptoms, or very mild ones, yet still be infectious to other people.

Q: Will warmer weather help stop the spread of the virus?

We don’t fully know the impact of the weather on the virus, but the family of viruses of which coronavirus is part, thrive better in cold, dry environments. But I don’t think we can tell for sure if a warmer temperature or more humidity would make this virus die down.

Q: How long does the virus stay alive on a surface?

It can stay on a surface for as little as six hours to as many as six days. Most reports say two to three days for surfaces like plastic and stainless steel, and one day for cardboard. But disinfectants, such as the disinfecting household wipes, usually take less than a minute to sanitize a surface and for the virus to be destroyed.

Medical workers wearing protective clothing against COVID-19 in Daegu, South Korea. (Photo: AFP)

Q: Will the coronavirus return next year on this scale?

Once a virus becomes a pandemic and is embedded in every country, the likelihood of it returning is high. At this point, given the numbers we are looking at, the likelihood of it coming back is actually quite high. But if it does come back, many of us will be immune to it or have mild symptoms because it will no longer be a new virus to our bodies. And if a vaccine is available, we will have potential protection from that, as well.

Q: Which countries are showing successful models for controlling the outbreak?

The two countries I know where the numbers are plateauing or going down significantly are China and South Korea. Hong Kong and Taiwan have also been successful in controlling this epidemic in their countries. We should pay attention to what they are doing. Their control strategies started in January and the number of cases in both countries have gone down significantly since then.

We are learning from China and South Korea that their control strategies have managed to contain the outbreak by identifying the cases, isolating those infected, and preventing others from getting exposed. I’m optimistic that other countries that take the outbreak seriously and step up their intervention can achieve the same result.

Of course each country’s response to the outbreak will not be exactly the same due to differing political systems and resources. The Chinese and South Korean responses have actually been different. China’s response is much more quarantine-based: locking down cities and restricting movement. While South Korea has greatly expanded testing capability and have been very aggressive in isolating cases and trying to immediately identify who an infected person was recently in contact with.

Q: How will the outbreak affect mental health?

We should not neglect the mental health toll of this outbreak. Social distancing, a preventative measure against the virus, is going to take a mental health toll. There is much fear and anxiety and that can drive self-harming behaviors. Some people don’t know how to manage their anxiety and fear and are turning to substance use to give them temporary relief.

In times of outbreaks, we can all spend too much time worrying about things. The World Health Organization recommends eating and sleeping well and exercising and keeping in communication with family and friends through phone and social media.

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