Americans 90% Susceptible to COVID:CDC

A high-placed medical official says most of the U.S. remains susceptible to a coronavirus infection.

COVID-19 has spread across America at varying rates since it crossed U.S. shores in January, infecting as much as 15% to 20% of the population in some states and less than 1% in others, he said. One state said almost a quarter of its residents have had the coronavirus sometime this year, he added.

Dr. Robert Redfield, director of the Centers for Disease Control and Prevention, told lawmakers Wednesday the CDC is in the process of a "very large" study that seeks to more precisely determine how widely the virus has spread across the country.

The rate of infection is important because epidemiologists think infection generally conveys some immunity against the virus for at least a few months.

The coronavirus, which has killed more than 200,000 Americans, has infected more than 6.8 million, or roughly 4.8% of the U.S. population, according to data compiled by Johns Hopkins University and the U.S. Census Bureau. However, the true spread of the virus is likely much higher, Redfield has previously said, as many mild and asymptomatic cases go undiagnosed.