New research shows that the coronavirus may kill between 5 and 10 people per 1,000 infections. That means the fatality rate hovers between 0.3% and 1.5% of people infected, making it more lethal than the seasonal flu, but not as deadly as Ebola, SARS and other recent emerging infectious diseases.

The reason it’s actually killing more people than the other viral diseases is that COVID-19 is highly contagious.

“It’s not just what the infection-fatality rate is. It’s also how contagious the disease is, and COVID is highly contagious,” Dr. Eric Toner, senior scholar at the Johns Hopkins Bloomberg School of Public Health and an expert in pandemic preparedness, told The Wall Street Journal. “It’s the combination of the fatality rate and the infectiousness that makes this such a dangerous disease.”

Already the disease has claimed the lives of over 609,000 people globally with nearly 25% of the fatalities in the U.S. Statistically, it has killed 4.2% of confirmed cases, well over the estimated fatality rate researchers suggest after analyzing data from 26 studies. According to the Journal, the discrepancy lies in the number of unconfirmed cases. Often people with mild symptoms of COVID-19 go undetected. Officials at the U.S. Centers for Disease Control and Prevention conducted a nationwide survey and found that for every known case of COVID-19, approximately 10 went unrecorded.