Nearly 60% of Americans—including around 75% of children—have been infected with the coronavirus, according to a new CDC report, news that comes as Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases, said on Tuesday the United States is now "out of the pandemic phase."

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Nearly 60% of Americans have been infected with the coronavirus

For the report, CDC analyzed blood samples the agency receives from commercial blood testing laboratories, performing additional antibody testing on samples collected during regular doctors' office visits, routing physical exams, and pre-surgical tests.

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According to Kristie Clarke, a CDC official who wrote the report, the blood test is able to detect coronavirus antibodies at least one to two years after infection. CDC is also able to determine whether antibodies were caused by a vaccine or an infection.

CDC found the omicron wave in the United States led to large increases in the percentage of Americans infected with the coronavirus. According to the report, 33.5% of Americans had been infected with the virus in December 2021. That number jumped to 57.7% in February 2022.

Similarly, between December 2021 and February 2022, the percentage of children ages 11 and younger infected with the coronavirus increased from 44.2% to 75.2%, while the percentage of children ages 12 to 17 infected with the virus rose from 45.6% to 74.2%.

In addition, the percentage of adults ages 18 to 49 infected with the virus increased from 36.5% to 63.7% during that same period, while the percentage of infected adults ages 50 to 64 increased from 28.8% to 49.8% and the percentage of infected adults ages 65 and older increased from 19.1% to 33.2%.

When asked why such a high percentage of children were exposed to the coronavirus compared with adults, Clarke noted that younger populations had the lowest vaccination rates.

What this means for the pandemic

In the report, CDC noted the data doesn't suggest people have protection against the coronavirus going forward, especially against any new variants that may be adept at evading antibodies.

"We continue to recommend that everyone be up to date on their vaccinations, get your primary series and booster, when eligible," CDC Director Rochelle Walensky said.

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Regarding prior infections, Walensky said, "We don't know how long [ago] that infection was. We don't know whether that protection has waned. We don't know as much about that level of protection than we do about the protection we get from both vaccines and boosters."

Clarke also emphasized the importance of getting children fully vaccinated against the coronavirus, even if they've already been exposed to it.

When new variants appear, "that is when we start to see more cases of reinfection," Clarke said. "So when you're looking at whether to vaccinate a child, you need to also think about giving them broad protection … not just [from] infection they might have had with omicron. The vaccine … really maximizes the protection to kids."

Still, a high percentage of prior infections with the coronavirus could mean there will be fewer cases of severe Covid-19, according to Florian Krammer, an immunologist at the Icahn School of Medicine at Mount Sinai.

"We will see less and less severe disease, and more and more a shift toward clinically mild disease," he said, adding that it will be "more and more difficult for the virus to do serious damage."

However, experts noted that even if a small percentage of those exposed to the virus develop long Covid, that is still millions of people who will have the condition.

"The long-term impacts on health care are not clear but certainly worth taking very seriously, as a fraction of people will be struggling for a long time with the consequences," said Bill Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health.

While there's often a focus on preventing hospitals from being overwhelmed during a surge of Covid-19 cases, "we should also be concerned that our health care system will be overwhelmed by the ongoing health care needs of a population with long Covid," said Zoë McLaren, a health policy expert at the University of Maryland, Baltimore County.

The US is 'out of the pandemic phase'

Meanwhile, in a briefing on Tuesday, Ashish Jha, the White House Covid-19 coordinator, said that while the 300 Covid-19 deaths per day is "still too high," the current number of hospitalizations is at an all-time low, and those numbers in context of rising Covid-19 case numbers amount to a promising "inflection" point.

Jha noted that, given how contagious the coronavirus is, it would be "hard to ensure that no one gets Covid in America."

"That's not even a policy goal," he added. "The goal of our policy should be: obviously minimize infections whenever possible, but to make sure people don't get seriously ill."

In addition, Fauci on Tuesday noted the United States is now "out of the pandemic phase," no longer seeing "tens and tens and tens of thousands of hospitalizations and thousands of deaths. We are at a low level right now."

"We're really in a transitional phase, from a deceleration of the numbers into hopefully a more controlled phase and endemicity,” Fauci said.

Fauci added that the virus will never be eliminated, but it can be dealt with if its level of spread is "very low" and people are "intermittently" vaccinated. (Sun et al., Washington Post, 4/26; Joseph/Cooney, STAT News, 4/26; Mahr, Politico, 4/26; Mandavilli, New York Times, 4/26; Stobbe, Associated Press, 4/26; Walker, MedPage Today, 4/26; Weiland, New York Times, 4/27; Pietsch/Achenbach, Washington Post, 4/27; Thomas, CNN, 4/27)