More than half of Americans have been infected with COVID-19: CDC

More than half of Americans show signs of a previous COVID-19 infection, including three in four children, a new report released on Tuesday showed.

The estimated proportion of people in the United States with detectable, infection-induced antibodies jumped from 33.5 percent in December 2021 to 57.7 percent by February 2022, according to the report of the U.S. Centers for Disease Control and Prevention (CDC).

During the December to February period, 75.2 percent of children aged 11 and younger had infection-related antibodies in their blood, up from 44.2 percent in the prior three-month period. Among those aged 12-17, 74.2 percent carried antibodies, up from 45.6 percent from September to December.

As of February 2022, approximately 75 percents of children and adolescents had serologic evidence of previous infection with COVID-19, with approximately one third becoming newly seropositive since December 2021.

These findings illustrate a high infection rate for the Omicron variant, especially among children, said the CDC.

"Seropositivity for anti-N antibodies should not be interpreted as protection from future infection. Vaccination remains the safest strategy for preventing complications from COVID-19 infection, including hospitalization among children and adults," said the report.

CDC's Kristie Clarke, co-author of the report, told a media briefing Tuesday that the finding means many people have at least some immunity to the virus.

But CDC officials recommend all eligible persons stay up to date with vaccination, including those with previous COVID-19 infection, because vaccination provides the strongest, broadest protection against getting seriously ill.

COVID-19 cases continue to rise, going up 23 percent last week to 44,416 a day. Deaths continue a months-long decline to 314 a day, or 13 percent less than the week before. Hospitalizations rose for the second week in a row, up 6.6 percent over the previous week, largely driven by subvariants of Omicron, CDC Director Rochelle Walensky said during the briefing.

According to the latest data from Johns Hopkins University, the total number of COVID-19 cases in the United States has exceeded 81 million, with 991,940 related deaths so far.

Walensky said the BA.1 variant, which caused the Omicron wave, now only accounts for 3 percent of U.S. transmission and that a subvariant of BA.2.121, first discovered in upstate New York, makes up nearly 30 percent of cases in the country.