94.9% of the Population Have COVID-19 Antibodies... 36.1% Have Natural Infection Antibodies (Supplement)

Bangdaebon, Survey of 1,612 Participants in the Korea National Health and Nutrition Examination
Infection Antibody Prevalence 0.6%p Higher Than Cumulative Incidence During Same Period

[Asia Economy Reporter Kim Young-won] More than 9 out of 10 citizens have been found to possess antibodies through COVID-19 vaccination or natural infection.

The Central Disease Control Headquarters announced on the 14th that a survey on COVID-19 antibody positivity rates was conducted from January to April among 1,612 participants aged 10 and above from the National Health and Nutrition Examination Survey across 16 cities and provinces nationwide, revealing an overall antibody positivity rate of 94.9%.

The antibody positivity rate refers to the proportion of individuals possessing antibodies that bind to the S antigen and N antigen of the COVID-19 virus. S antibodies can be produced through both natural infection and vaccination, while N antibodies are formed only through natural infection.

The survey results showed that from January to April, the S antibody positivity rate among all subjects was 94.9% (1,530 people), and the N antibody positivity rate was 15.0% (241 people).

By month, the S antibody positivity rate remained relatively stable at around 93-95%, but the N antibody positivity rate increased significantly with the Omicron wave, rising from 0.6% in January, 2.5% in February, 16.5% in March, to 36.1% in April.

The 36.1% antibody positivity rate due to natural infection in April is 6.6 percentage points higher than the nationwide cumulative COVID-19 incidence rate of 29.5% for those aged 10 and above during the same period. The Central Disease Control Headquarters explained, "As confirmed cases continue to increase within the community, it is believed that not only antibody-positive individuals from natural infection but also undiagnosed infected individuals have increased."

Despite the high antibody possession rate, authorities explained that the current situation cannot be regarded as 'herd immunity.' At a briefing, Kwon Jun-wook, Director of the National Institute of Health, stated, "There appear to be differences in the protective efficacy of antibodies produced by vaccination or natural infection depending on the variant," adding, "It is difficult to simply refer to herd immunity based on the absolute cumulative number of confirmed cases."

Regarding the duration of natural immunity, Director Kwon explained, "According to textbooks, antibodies from natural infection are considered to last more than six months," and added, "Research and investigations are currently underway for detailed subgroups."

This survey has limitations in representing the entire population as the survey regions varied monthly, the scale was small, and the subjects were set at age 10 and above. To more accurately confirm the scale of natural infections and analyze epidemic risk factors, the Central Disease Control Headquarters will begin a large-scale nationwide antibody positivity rate survey starting next month.

The large-scale antibody positivity rate survey will target 10,000 people quarterly, aiming for 30,000 people this year, across 17 cities and provinces nationwide, including citizens aged 5 and above. This survey will include not only antibody possession status but also underlying diseases, vaccination history, and outpatient visits.

Previously, the government announced it would start the first survey in May, conduct specimen collection and analysis from early June, and release the first survey results in July, but the schedule was delayed due to administrative procedures.

Director Kwon stated, "We plan to select researchers within this month and currently plan to start the project from July 8," adding, "The second quarter covers April, May, and June; although antibodies can form immediately in some cases, generally they form about 1 to 3 weeks later, so we are considering starting from July 8."

This content was produced with the assistance of AI translation services.