SEOUL -- There is almost no chance for South Korea to stem a new coronavirus pandemic through collective immunity as there are not many "hidden" or untraceable patients who unknowingly recovered after being infected with COVID-19, according to a state anti-epidemic center.
For its second survey in two months, the Korea Disease Control and Prevention Agency (KDCA) collected blood samples from 1,440 people from June 10 to August 13. Antibodies were detected from one person. Experts believe it's impossible to ride out a COVID-19 crisis through collective immunity until vaccines are developed.
Antibody tests are used by researchers to estimate the extent of coronavirus infections at a population level. When a virus invades the body, the immune system produces antibodies to fight it. Only one out of 3,055 people was found to have developed antibodies in the first round of antibody tests from April 21 to June 19.
Medical experts concluded that the second survey did not reflect reality as it was carried out before August 15 when the Seoul metropolitan area reported a sudden rise in daily new cases, KDCA head Jeong Eun-kyeong told a regular press briefing. "The number of tests is small to find an asymptotic infection rate," she said.
Since the number of new cases soared to 441 on August 27, daily infections have been gradually down to 109 on September 14. However, health officials were still on alert as sporadic cluster infections showed no signs of slowing. So far, 22,285 people have been infected with COVID-19, leaving 363 dead and 3,433 others under treatment.