LONDON, (Xinhua) -- More than half of Americans have contracted COVID-19 at least once, according to a study recently released by US medical authorities.

A report published by Reuters news agency on Tuesday, citing a study issued by the US Centers for Disease Control and Prevention, said that about 58 percent of the total US population and more than 75 percent of young children have been infected with the virus since the beginning of the epidemic.

US Centers for Disease Control and Prevention director Rochelle Walensky said infection and hospitalization rates in the United States had risen in the past week.

"The presence of antibodies caused by infection does not necessarily imply protection against future infection," said Kristi Clark, co-author of the study.

"We haven't examined whether people have a level of antibodies that would prevent reinfection or severe disease," he added.