As the number of confirmed cases of COVID-19 continues to increase in the United States, health organizations and government officials are continuing to warn the most at-risk populations, urging them to take extra precautions.

While the current numbers of cases do not come close to approaching some of history’s worst outbreaks, the data is considered largely incomplete and the outbreak has also not peaked. The Centers for Disease Control and Prevention has outlined scenarios for the outbreak that suggest that between 160 million and 214 million people in the United States could eventually be infected, and that as many as 200,000 to 1.7 million people could die — many of them at-risk adults.

Nonprofit health care policy organization Kaiser Family Foundation, the source of the data used in this story, concluded that “these estimates confirm the need to take unprecedented efforts to minimize the spread of the coronavirus.” (For some historical context, these are the worst outbreaks of all time).

Most people exposed to the virus will not become seriously ill, but infection rates suggest anyone can be infected and pass it to others. This is especially important to bear in mind when it comes to the large segment of the population who are at risk of developing severe disease due to the virus.

The CDC considers older adults and those with underlying conditions such as diabetes, heart disease, and lung disease to be at higher risk. Approximately 41% of U.S. adults ages 18 and older (105.5 million people) are at greater risk of serious illness if they become infected with the virus that causes COVID-19. An estimated additional 1.3 million people living in nursing homes are not only at high risk of serious illness but also of the virus spreading faster because of their dense, communal living conditions.

An estimated 5.7 million adults who are at higher risk of getting a serious illness if they become infected with the novel coronavirus are uninsured, including 3.9 million adults under age 60 and 1.8 million who are ages 60-64.

Click here for every state’s number of at-risk adults in the coronavirus pandemic
Click here for our methodology