Two high school seniors in Incheon tested positive for COVID-19, leading the school they attended as well as two nearby high schools to delay resumption by a day, according to the city's education office.
Bloomberg reported the research shows that antigen tests can not distinguish between dead and viable virus particles, potentially giving the wrong impression that someone who tests positive remains infectious.
After an unprecedented five-month break, South Korean students are returning to their classrooms as government health officials declared that the country may have avoided a second wave of infections. It seems like a relief after newer evidence has shown, such people aren't capable of transmitting the infection to others, while they could also have antibodies preventing them from falling sick.
The South Korea Centre for Disease Control and Prevention examined 285 COVID-19 survivors who had recovered, tested negative and then tested positive for a second time.
Last month, research showed that the existing PCR tests for the novel coronavirus's nucleic acid can not distinguish dead and viable virus particles, this would give a false impression that if someone tests positive, they would remain infectious.
None of the 790 people that the patients came into contact with were found to be infected with COVID-19, the disease caused by the virus.
With that, the researchers believe that these people were shedding either dead or noninfectious particles. "We have not found evidence that those cases are contagious". Instead, they will be referred to as "PCR re-detected after discharge from isolation", according to a report from the Korean CDC that was obtained by Bloomberg.
"Under the new protocols, no additional tests are required for cases that have been discharged from isolation", researchers said.
The evidence from South Korea indicates that health officials in the country will remove people who have recovered from COVID-19 from being considered infectious.
This could be good news for countries hoping to re-open after their attempt at flattening the curve.
"We can proceed with in-person classes when students and staff are safe from COVID-19". Nor do they know how long any immunity may last.
Nevertheless, recent research from a biotech company in collaboration with the University of Washington School of Medicine found an antibody in a former SARS patient that could block SARS-CoV-2.