HONG KONG—February 19, 2020—Scientists at the Chinese Center for Disease Control and Prevention recently completed a comprehensive study of more than 72,000 confirmed and suspected cases of the novel coronavirus (SARS-CoV-2), which causes coronavirus disease (COVID-19). CNN reports that the novel coronavirus study, which was published in the Chinese Journal of Epidemiology, has revealed new information about how contagious and how deadly the virus is compared to similar viruses.

The Chinese study found that SARS-CoV-2 is more contagious than the related coronaviruses that cause SARS and MERS, two other severe respiratory infections. Because the COVID-19 infection spreads more easily, many more people have been infected and the outbreak has led to more deaths than SARS or MERS, but on a case-by-case basis, COVID-19 is actually far less fatal. According to CNN, the 2003 outbreak of SARS had a mortality rate of 9.6%, and MERS has a fatality rate of 35%. Current data from the novel coronavirus study suggests that the mortality rate of COVID-19 is 2.3%, and experts expect that rate to come down as less severe cases of the disease are accounted for.

Dr. Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases, explains that a large number of minimally symptomatic cases are likely not being counted in these early estimates, according to CNN. “So I would think at tops [the fatality rate is] 2% and it likely will go down when all the counting gets done to 1% or less,” said Dr. Fauci. “That’s still considerable if you look at the possibility that you’re dealing with a global pandemic,” he cautioned.

For context, seasonal influenza has a mortality rate of just 0.1%, but because the flu is so highly contagious, it affects tens of millions of people every year and kills tens of thousands in the U.S. alone, according to CNN. So if COVID-19 does become a global pandemic the effects would be severe, which is why health officials and governments are taking precautions to stop the spread of infection. Currently the outbreak remains highly concentrated in mainland China, where the virus originated in Hubei Province. CNN reports that both Beijing and Shanghai are on lockdown to limit the spread of infection. In the U.S., travelers returning from China are placed in a 14-day quarantine as a precaution.

According to CNN, more than 1,800 people have died from COVID-19, but only five deaths occurred outside China. As with influenza, many of the deaths occur in the elderly and in those with preexisting conditions or compromised immune systems. Relatively few cases of the virus are seen in children, but more research is needed to determine why this is.

For the last two weeks, the number of new cases in China outside of Hubei Province has fallen, which is encouraging, but experts caution that it’s too soon to be sure of anything, according to CNN. “Trends can change as new populations are affected. It’s too early to tell if this reported decline will continue,” said Dr. Tedros Adhanom Ghebreyesus, director-general of the World Health Organization. “Every scenario is still on the table.”