More than half of the U.S. has had COVID-19, antibody study indicates

About 58 per cent of the U.S. population has had COVID-19 since the start of the pandemic in 2020, according to a U.S. nationwide blood survey released on Tuesday.

Following the record surge in COVID-19 cases during the Omicron-driven wave, some 58 per cent of the U.S. population overall and more than 75 per cent of younger children have been infected with the coronavirus since the start of the pandemic, according to a U.S. nationwide blood survey released on Tuesday.

The study of blood samples sent to laboratories between December and February – when Omicron cases were raging – showed children, many of whom remain unvaccinated, had the highest rates of infection during that surge, while people 65 and older – a heavily vaccinated population – had the lowest.

Scientists looked for specific antibodies produced in response to the SARS-CoV-2 virus that are only present after an infection and are not generated by COVID-19 vaccines.

In children aged 11 and younger, 75.2 per cent were positive for infection-related antibodies from December to February, up from 44.2 per cent in the prior three month period.

In children aged 12-17, 74.2 per cent carried antibodies, up from 45.6 per cent between September and December. The overall rate was 33.5 per cent for the entire population during that earlier time period.

“Having infection-induced antibodies does not necessarily mean you are protected against future infection,” said Kristie Clarke of the U.S Centers for Disease Control and Prevention (CDC) during a media briefing to discuss the data. “We did not look at whether people had a level of antibodies that provides protection against reinfection or severe disease.”

The CDC stressed that vaccination remains the safest strategy for preventing complications from COVID-19.

Samples were collected from commercial laboratories testing blood for reasons unrelated to COVID-19, such as routine medical care. Traditional methods of disease surveillance do not capture all COVID-19 cases because some are asymptomatic, not diagnosed, or not reported, the CDC said.