(CNN)An investigation of a major coronavirus outbreak aboard the USS Theodore Roosevelt aircraft carrier may reveal clues as to how Covid-19 affects younger adults.
"This is the first major look at Covid-19 infections among healthy young adults that the CDC has released," said Daniel Payne, an epidemiologist with the US Centers for Disease Control and Prevention, which collaborated with the US Navy on the investigation.
More than 1,000 of the ship's nearly 4,900-member crew tested positive for Covid-19 following the outbreak. After spending weeks at a port in Guam, the ship returned to sea last month.
The majority -- nearly 60% -- of sailors in the study who had antibodies had neutralizing ones, "a promising indicator of at least short-term immunity," the researchers wrote.
Most reported mild or no symptoms, and those who took preventive measures -- such as face masks and social distancing -- were less likely to become infected.