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97% of Koreans have Covid-19 antibodies, says a study

Posted September. 24, 2022 07:26,   

Updated September. 24, 2022 07:26


A study found that about 97 percent of the nation's population have antibodies to COVID-19. It turned out that roughly 10 million "unconfirmed infections" have contracted the coronavirus and thus have antibodies, yet have not been officially confirmed by the authorities.

On Friday, the Korea Disease Control and Prevention Agency (KCDA) and the National Institute of Health published the "National SARS-CoV-2 Antibody Study Results" as above. This is the outcome of a study conducted from Aug. 5 to Sept. 6 on a sample group of 9,901 people over the age of five in 17 cities and provinces across the country. This is the first time a large-scale nationwide epidemiological study has been conducted at the government level.

The study results indicate that 97.38 percent of the population has COVID-19 antibodies. The rate of natural immunity-induced antibody-positive is 57.65 percent, and the rate of vaccination-induced antibody-positive is 39.73 percent. This means that 97 out of 100 people have either been naturally infected with COVID-19 or vaccinated against it. However, having antibodies does not necessarily prevent COVID-19 infection.

“The high rate of the antibody-positive population overall does not equate with the fact that the population has a strong defense mechanism against the virus,” said Kwon Jun-wook, director of the Korea National Institute of Health. “If the immunity-induced antibody disappears over time and a new virus variant appears, the existing protective effect may be further reduced.” This is why additional rounds of vaccine shots are needed if more than four months have passed, even if you have been vaccinated or have been infected with COVID-19.

Furthermore, 57.65 percent of study subjects were found to have "N (nucleoprotein) antigen," meaning that they "have been infected with the coronavirus." And this figure is 19.5 percentage points higher than the cumulative number (38.15 percent) of confirmed cases in the population. About 10 million people, or 19.5 percent of the total population, have been infected with COVID-19, but it failed to be included in government statistics. It is presumed that they did not know that they were infected with the virus or that they did not get tested even though they had symptoms.

Medical observers expect the number of unconfirmed infection cases to be greater than this. “The N antibody disappears over time. The antibody-positive rate the researchers estimated (57.65 percent) may have been underestimated,” said Professor Kim Dong-hyeon at Hallym University College of Medicine, who participated in the antibody study. “There should be more hidden infection cases.”

The number of "unconfirmed infections" in their 50s was 27.62 percent, followed by those in their 40s with 24.83 percent. "Further analysis should be conducted to find the exact reason, but internal discussions have concluded that these people being the 'heads of the family' or 'self-employed,’ thus choosing not to be tested due to concerns over possible quarantine, may have been reflected in the study result,” Professor Kim said.

noel@donga.com · ksy@donga.com