Everything you need to know about the coronavirus from China

Public health experts around the globe are scrambling to understand, track, and contain a new virus that appeared in Wuhan, China, at the beginning of December 2019. The World Health Organization named the disease caused by the virus COVID-19, which references the type of virus and the year it emerged.

You can see where and how many cases of the illness have been reported in this map. So far, there have been over 80,000 confirmed cases and 2,770 deaths. Over 30,000 people have recovered from the illness. The majority of the illnesses are still in China, but cases have been reported in dozens of other countries. There are large outbreaks of the disease in South Korea, Italy, Iran, and Japan.

As this important story continues to unfold, The Verge will update this page with all the latest news and analysis. Our hope is to answer all of your questions as people work to understand this virus and contain its spread.

Table of contents

Where did the virus come from?

At the end of December, public health officials from China informed the World Health Organization that they had a problem: an unknown, new virus was causing pneumonia-like illness in the city of Wuhan. They quickly determined that it was a coronavirus and that it was rapidly spreading through and outside of Wuhan.

Photo by Kevin Frayer/Getty Images

Coronaviruses are common in animals of all kinds, and they sometimes can evolve into forms that can infect humans. Since the start of the century, two other coronaviruses have jumped to humans, causing the SARS outbreak in 2002 and the MERS outbreak in 2012.

Scientists think this new virus first became capable of jumping to humans at the beginning of December. It originally seemed like the virus first infected people at a seafood market in Wuhan and spread from there. But one analysis of early cases of the illness, published January 24th, found that the first patient to get sick did not have any contact with the market. Experts are still trying to trace the outbreak back to its source.

The type of animal the virus originated from is not clear, although one analysis found that the genetic sequence of the new virus is 96 percent identical to one coronavirus found in bats. Both SARS and MERS originated in bats.

So is this the same as SARS?

The new virus isn’t SARS, although that also began in China. Because it comes from the same viral family as SARS, it has some similarities, but it’s an entirely new virus. However, the commonalities mean scientists and public health officials can use what they’ve learned from the past outbreak to try to stop this one.

China lied to the WHO about SARS. Is it lying about this, too?

During the SARS outbreak, Chinese officials attempted to conceal cases from WHO inspectors and limit information, both internally and externally. This time, officials quickly reported the outbreak of the new virus to the WHO, which praised their quick response and transparency in a press conference. China is also allowing a team of WHO experts to assist Chinese public health officials with the ongoing work, the organization announced January 28th.

The US Department of Health and Human Services also said China has been more transparent than they were with SARS. “The Chinese government’s level of cooperation is completely different from what we experienced in 2003,” said department Secretary Alex Azar during a press conference.

But critics and Chinese citizens were skeptical: there were early concerns that Chinese officials were undercounting the number of illnesses and are classifying deaths that might have been from the virus as being from pneumonia. Wuhan police also investigated citizens for spreading what it called rumors online at the start of the outbreak.

(It’s important to note that China isn’t the only country known for concealing the extent of public health problems. In the US, for example, dozens of cities have concealed the amount of lead in their public water supply.)

How dangerous is this new virus?

Right now, it’s hard to say for sure.

It takes information about both how severe an illness is and how easily it can spread to determine how “bad” it can be. Epidemiologists often use this tool to assess new strains of the flu, for example, to guide decision-making:

Image: Centers for Disease Control

If an illness isn’t very severe (and kills only a small percentage of people), but it’s highly transmissible, it can still cause devastating effects — if something affects millions, the small percentage it kills will still be a high number of fatalities.

The WHO named the illness caused by the coronavirus COVID-19 — “co” and “vi” for coronavirus, “d” for disease, and “19” for the year when the disease emerged.

The symptoms of COVID-19, which have ranged from mild, like those in a cold, to severe. Around 80 percent of confirmed cases are mild. That’s 80 percent of the cases that we know about. It’s still possible that there are many more mild cases of the illness that haven’t been flagged, which would shrink the percentage of cases that are severe. About 5 percent of cases are critical, and it appears around half of the people with critical cases of the illness die from it.

So far, the fatality rate for the new illness is around 1 or 2 percent, though it’s too early to say for sure, and that could change as the outbreak progresses. The fatality rate for SARS was about 14 to 15 percent. Most deaths in this outbreak have been in older people and those who have underlying health issues, like heart disease, hypertension, and diabetes. In that group, the fatality rate for the new coronavirus is much higher: it’s around 14 percent for people over the age of 80, for example.

How fast is the virus spreading?

The virus is moving rapidly around the world. In China, sick people have been infecting others through person-to-person transmission since the start of January. The new coronavirus spread quickly in the contained environment on the cruise ship the Diamond Princess. Clusters of high numbers of cases have appeared in Italy, Iran and South Korea, and it’s possible that many more cases outside of China haven’t been detected. Experts say that it may not be possible to contain a wider spread of the virus.

Early evidence suggested that, like other coronaviruses, the virus jumps between people who are in very close contact with each other, and probably spreads when an infected person sneezes or coughs.

Chinese officials have said that they have seen cases where people with the virus infected others before they start showing symptoms, but there isn’t detailed evidence to say if or how much that is happening. Research out of China showed that people without symptoms still have high levels of the virus in their throats and noses, meaning they may be passing it along if they cough or sneeze. A family in Anyang, China, also appeared to be sickened by an asymptomatic family member, reported a study in JAMA.

If that’s happening regularly, containing the spread of the virus will be more complicated. And even if it was happening, it probably wouldn’t significantly affect the outbreak, said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, in a press conference. “Even if there is some asymptomatic transmission, in all the history of respiratory borne illness, asymptomatic transmission has never been the driver of outbreaks,” he said. “An epidemic is not driven by asymptomatic carriers.”

The WHO says that researchers think each sick person will go on to infect, on average, between 1.4 and 2.5 additional people, though that’s only a preliminary estimate. Other teams of researchers have published their own estimates, with most saying a sick person will infect an average of around two or three people.

Those numbers are called the virus’s R0 (pronounced “R-naught”). The R0 is the mathematical representation of how well an infection might be able to spread. The higher the number, the more potentially spreadable it can be. For comparison, the R0 for SARS was between two and five. But that doesn’t mean each sick person will actually infect that many people; quarantines and other actions taken to control outbreaks of a virus can bring down the number of people a sick person infects.

Can we treat this virus?

There aren’t any proven treatments for COVID-19, but there are dozens of studies underway to try and find some. One leading candidate is remdesivir, an antiviral medication originally developed to treat Ebola. There are clinical trials testing it in patients in China and in the US.

Research teams and pharmaceutical companies are also working to develop a vaccine that can protect people from infection. However, vaccine development takes a long time. Even if everything goes smoothly, it will be around a year to 18 months before one is available, said Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases.

How can I protect myself?

Based on what we know so far, you can protect yourself with the same measures you’d take (and should be taking) to protect yourself against the flu: wash your hands, cover your mouth when you cough, and stay away from people who are sick. It’s totally normal to feel anxious, and there are ways to reduce that anxiety, like by distracting yourself with other activities or keeping the risks in perspective.

If you live in the US, it’s still far more likely that you have the flu or the common cold. It’s still flu season, and high levels of flu activity aren’t expected to die down anytime soon. (It’s not too late to get a flu shot!)

Should I cancel my vacation to Asia?

The US State Department raised the travel advisory for China to a level 4, saying Americans shouldn’t travel to China because of the virus. Level 4 is the most severe warning issued. It applies only to areas with a “greater likelihood of life-threatening risks.” US citizens currently in China should “consider departing using commercial means,” the alert said.

The CDC also issued a level 1 travel advisory for Hong Kong, saying that anyone traveling there should take precautions by washing their hands and avoiding sick people. It’s issued level 2 travel advisories for Japan and South Korea, saying that people who might be at higher risk from the virus — older adults and people with chronic health issues — should not travel there unless absolutely necessary. Both countries have high numbers of people with confirmed infections from the new coronavirus.

Many countries have travel restrictions in place and are placing travelers in quarantine if they’re suspected of having the disease or if they’ve been somewhere it’s spreading widely. Anyone taking a trip should prepare for their plans to be disrupted if the situation changes.

How is China trying to stop the virus?

On January 22nd, officials in Wuhan shut down all transportation in the city, which is home to over 11 million people. They closed buses and subways and canceled all flights and trains in and out of the city. The director-general of the WHO applauded the decision, saying that it would help control the outbreak and slow the spread into other countries. Fifteen other cities, home to a total of 46 million people, are locked down as well, The New York Times reported.

Major cities across the country canceled celebrations for the Lunar New Year, a huge holiday in China.

How at risk is the United States?

It’s hard to say how significant of an effect it could have in the United States, but the CDC says it’s likely that the virus will spread through the country at some point. The agency is using its guidelines for pandemic influenza as a starting point for preparations. People in the US should prepare for disruptions to everyday life, said Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases at the CDC, during a press call.

There are 14 confirmed cases in the US in people who either traveled to China (11 people) or caught the virus from spouses who had traveled there (2 people). There are also 45 people who were diagnosed with COVID-19 after being evacuated by the US State Department from Wuhan and the Diamond Princess cruise ship and placed under quarantine in the US.

The US is still only testing people for the coronavirus if they are sick and have been to China or Wuhan. The CDC plans to do more widespread surveillance for the virus to see if there are cases it’s missing, but problems with testing kits slowed its start. Other countries are looking more aggressively for cases — and finding them.

US Secretary of Health and Human Services Alex Azar declared a public health emergency in response to the coronavirus. All flights from China to the US are being diverted to seven airports, and any US citizen who has traveled to China will be asked to self-quarantine for 14 days. Any US citizen who has been in the Hubei province (where Wuhan is and where the virus originated) will be held under a formal quarantine for 14 days.

In addition, any foreign national who has traveled to China in the past 14 days will not be allowed to enter the US, unless they have immediate family members there, according to a proclamation from President Trump. That decision is not supported by the WHO, which said countries should not restrict travel or trade in their response to the virus.

How is the virus affecting businesses that operate in China?

A number of airlines, including United Airlines, British Airways, and Air Canada, are canceling some or all flights to and from China. United Airlines said their decision to do so was due to a drop in demand for those flights.

Tech companies like Apple started limiting employee travel to China even before the US State Department and CDC warned people against traveling there. South Korea’s LG banned travel to China completely, and both Facebook and Razer told employees who had recently returned from China to work from home.

Foxconn, the Taiwanese electronics company that has factories in China and makes products for tech companies like Apple, said the virus won’t impact their production. But China has officially extended the recent Lunar New Year holiday in an effort to curb the virus’ spread, which could delay normal production schedules. In a recent earnings call, Apple says it’s accounted for this uncertainty as it looks ahead to the next quarter.