An estimated 140 million people in the United States have been infected with the coronavirus, according to data shared by the Centers for Disease Control and Prevention.
Researchers evaluated nearly 72,000 blood samples to estimate the number of infections. The data, which goes through late January, reflects the increase in infections that occurred as the omicron variant began to spread throughout the country.
According to the data, the CDC estimates that a majority of the country’s children have had the virus at some point – nearly 60% of people 17 and under have been infected so far, in comparison with about 43% of the country as a whole.
In late November, the CDC’s blood sample analysis estimated that 103 million people in the country had been infected with the coronavirus, The Washington Post reported.
The increase in infections between then and the most recent analysis has largely been attributed to the highly transmissible omicron variant, which began spreading throughout the U.S. late last year. In late January, the variant was responsible for 500,000 cases a day, The Washington Post reported.
The CDC compiles its data by gathering blood tests conducted at commercial labs nationwide for reasons not related to COVID-19, such as a routine checkup or other medical treatment. The samples are evaluated for the presence of antibodies that could fight the coronavirus, and the percentage of people with antibodies is known as seroprevalence
The seroprevalence data provides estimates on the number of people with “resolving or past infection” and does not include people who have been vaccinated against the coronavirus and have no history of infection, the CDC says.
Although the study measures the presence of antibodies in various demographics, it does not measure how much antibody presence there is, the CDC said. Essentially, the agency said it can’t conclude that those with antibodies have a strong defense against reinfection.
The CDC said it didn’t have enough samples from Nevada, Utah, Arizona or North Dakota to generate estimates and include them in the analysis. At least half of the people in 14 states have been infected, the analysis shows, The Washington Post reported.
Wisconsin had the highest level of seroprevalence, implying the highest number of infections — an estimated 56.1% of the population, or around 3.2 million people, have been infected with COVID-19, according to the data. On the other end of the spectrum, Vermont had the lowest level of seroprevalence, with about 18% of the population, or 111,000 people, estimated to have been infected.
The estimated number of 140 million infections nationwide is “well over double” previous estimates from the government, according to The Washington Post.