Flattening the Curve: The South Korean Approach to COVID-19

March 19, 2020

by Steve Jang

Read me first: The objective of this post is to organize information about the Korean approach to the COVID-19/Coronavirus pandemic, and perhaps take away some learnings that can help us in the US and other countries. These are some notes I’ve pulled together from direct communications over the last 6 weeks with different trusted contacts on the ground in Seoul, as well as data from publicly available sources and articles.

However, please keep in mind that this is still secondary, not primary, information as I’m not in Korea, and I’m collecting information from others. Nor am I an epidemiologist, immunologist, or doctor — just a former research analyst and software entrepreneur, and now technology startup investor with a Korean-American background. I’ve included some articles and direct data in the notes below. If you have differing information on any of these topics, I gladly welcome any suggestions or corrections at steve dot jang at gmail.


South Korea was hit by COVID-19, a novel coronavirus, in mid-January 2020 and has been able to rapidly flatten the curve in 8 weeks using a comprehensive suppression strategy of:

  • High-Availability Testing
  • Clear Quarantine/Isolation Protocols
  • Extensive Contact Tracing
  • Social Distancing

— and without a complete shutdown of commercial and retail economy.

Their preparation came from prior experience with the MERS epidemic of 2015 and their execution of this plan included expedited regulatory approval, centralized operations command, distributed testing workflows, technology tools, and also empowered citizens to participate.

The following notes describe the above measures in more detail, along with some suggestions and questions for all of us in the US and other countries.

Table of Contents

  • South Korean COVID-19 Curve
  • Country Travel Ban Policy
  • City Quarantine Strategy
  • Household Quarantine Strategy
  • Clusters
  • Testing Criteria
  • Systems Design: Distributed Network Testing, Quarantine/Isolation/Treatment, and Contact Tracing
  • Overview of the Healthcare System in South Korea
  • Technology: Communication, Contact Tracing, and Supply Rationing
  • Community Awareness
  • Local Transportation, Travel, and Freight
  • Restaurants, Grocery, and Food Delivery
  • Education
  • Work
  • Religious Gatherings
  • What can we learn from this approach?

The COVID-19 Curve in South Korea

South Korea’s first known case was discovered in mid-January, which was the same time that the US had their first confirmed case. With immediate testing coverage, the Korean healthcare system was able to identify and isolate positive cases and effectively reduce daily new cases. The outbreak is still active, but they have the testing coverage and workflow now to have some confidence in their approach so far. By comparison, Italy was slower to test and quarantine the first cluster zone, and has faced a steep confirmed case curve. If you look at the country comparison chart below, the US is showing a similar confirmed case curve to Italy. This is troubling to say the least to us in the US.

source: Center for Disease Control (South Korea)
source: CoronaBoard.kr and various international government agencies

Country Travel Ban and Quarantine

South Korea didn’t adopt the more stringent Taiwanese approach, and has kept the borders and travel open despite an increasing amount of nations who have banned visitors from Korea. Why? South Korea is an exports-based economy, and the government sees the country’s economic future as very dependent on their trading partners, and in particular, China.

Chart of Imported Cases in South Korea

source: CDC (Korea)

Korean government did not place an immediate health inspection of travelers arriving from Hubei province and then a total travel ban on Chinese visitors, as Taiwan did progressively in late December of 2019 and late January of 2020. Today, anyone coming from Hubei province into Korea is either blocked or inspected/quarantined upon arrival (Korean nationals).

The Taiwan Approach

If Korea had followed the Taiwan model and implemented a tiered and rules-based travel ban on people who had been in China in the last 14 days the outcome might have been significantly better on the case number and fatalities. From a recent Foreign Policy magazine article:

When the first news about a mysterious illness in Wuhan started emerging in December 2019, Taiwan treated the news with utmost urgency.

There are many hundreds of thousands of Taiwanese working in China, which means there is a high frequency of flights and travelers between the country and Taiwan — although the numbers have shrunk since China started limiting tourism to the country for political reasons.

Taiwan took measures early on, including inspecting plane passengers coming from Wuhan starting Dec. 31, banning Wuhan residents on Jan. 23, suspending tours to China on Jan. 25, and eventually banning all Chinese visitors on Feb. 6.

Recognizing that it had to ensure an adequate supply of medical equipment, including face masks, for health professionals and the public, Taiwan’s government stopped exports of surgical face masks on January 24 while requesting local companies to step up production. Daily production is set to reach 10 million soon, divided between the public, medical, and industrial sectors.

The government also took control of face mask distribution from the private sector on Jan. 31, ensuring there would be no hoarding of supplies or exploitative pricing, as has happened in other places such as Hong Kong. Taiwan also implemented a purchasing policy on Feb. 6 in which every Taiwanese can buy a certain amount of adult and children’s masks per week from pharmacies and clinics for NT$5 ($0.17) each. And to allow for easier distribution and prevent long lines outside clinics, Taiwanese can now start ordering their masks online and pick them up at a later date.

To ensure coordination, Taiwan set up a unified command center, led by the Ministry of Health and Welfare, which manages resources, holds daily briefings, and is in control of public messaging. The authorities have also moved quickly to track down infected persons and map the cases to show the sources of infection. Educating the public on the risks of the illness and precautions to take through television notices and posters is also a big part of anti-coronavirus efforts.

The Korean approach isn’t without its detractors domestically. The decision to not ban visitors from China has been a major source of controversy among Korean citizens as the Korean government was seen by many as placing political and trade partner relations with China above health and safety of its own citizens. The first known case came on January 24 from a Chinese national visiting Korea from Wuhan, China and second case was Korean national who had returned from a business trip in Wuhan. There were an estimated 70,000 Chinese exchange students re-entering South Korea for university in the month of February after Lunar New Years celebrations at home. As caveat and context, the pre-existing political environment in Korea is extremely volatile with deep partisanship following an impeachment and removal of the prior president, and the controversy seems largely delineated by partisan lines.

Citywide-Area Quarantine

The country of South Korea is a democracy that tries to protect civil liberties in the American representative democracy model, and attempts to keep the semblance of normal life in times of crisis for both social and economic purposes. They didn’t force a lockdown or quarantine cities as happened in Wuhan. It would seem based upon today’s data that both strategies work, but perhaps just a matter of stage of outbreak.

The government did not force “full lockdown” quarantines or bans at city or provincial borders, by the national, provincial, or city governments. The government wanted to avoid having to stop intra- and inter-city commercial activity and any perceptions of blocking civil liberties. The first and main infected metro city area was Daegu, the home city location of the Shincheon-ji church group which was the patient zero group in Korea. Though there have been small spikes in other cities, the city of Daegu remains as 75% of total cases in Korea, and this church group as a cluster represents over 60% of total cases in Korea, according the Korean CDC.

Source: CDC; Yu-Sung Chang of SSG

Household Self-Quarantine

South Koreans can be often viewed as a collectivist society (versus individualist), which can have its advantages and disadvantages. Perhaps in times of crisis this can help with countrywide behavior change as we saw in the Asian Financial Crisis in the late 1990’s and in this current pandemic. The government and healthcare associations blanketed cities with a consistent and repeated message about Social Distancing and testing procedures.

Residents were strongly recommended to self-quarantine, but not required. Social Distancing was promoted in a widespread campaign of citywide messages, posters and signage via mobile messaging apps, text messages, buildings, buses, TV, newspapers, and radio. The ubiquity, frequency, and volume of this was massive and pervasive.

(Campaign graphic image by City of Seoul; In English for foreigners living in Korea)

The Seoul city government launched a “Hold up! Let’s Take a Break From Social Life” campaign to promote social distancing with specific instructions for residents, companies and local/national government coordination. Citizenry was advised to limit movement outside of one’s home to only essential work, medical, or grocery activity. No city government forced an official shutdown of all restaurants, retail stores, gyms, etc, but these social locations were all massively down in customer traffic and business.

Work-From-Home policy encouraged by government, but major corporations weren’t prepared for this type of remote work modality even with office work, and many jobs in Korea are manufacturing or retail service which are less likely to . It took large companies to take the public lead on this and then smaller companies quickly followed suit.

The recommended home self-quarantine for all residents and the clinical isolation (hospital bed) of cases has helped keep other larger cities outside of Daegu (3rd largest city in KR) relatively lower in case numbers as of 3/16:

Seoul — 253 total cases (3.1%)

Busan — 207 total cases (1.3%)

Daegu — 6,066 total cases (73.7%)

Daegu residents seemed to not only have stayed in their own home city, but also generally sequestered themselves at home. Also, there seemed to be a fear of public shaming in media and government prosecution among the populace. There was a sharp swell of public anger in media directed toward the Shincheon-ji church group, from which most of the Korean cases had come, and a well-publicized case of an individual named “Patient 31” that had disregarded social distancing and had infected several people at church, cafes, and buffet lunch at hotel.

source: CDC (South Korea); Reuters (Marco Hernandez, Simon Scarr, Manas Sharma)

The Importance of Clusters

Preventing, identifying and suppressing viral clusters immediately with proactive outreach, public communications, and contact tracing has been critical to the Korean approach.

The Korean approach also focused on identifying viral clusters that caused spikes of case numbers in Korea with traced epidemiological links, and then worked immediately to find everyone in contact with people of that cluster group or location. Then test, quarantine during diagnostic period, and isolate if tested positive. According to the CDC in Korea, these outbreak clusters were responsible for 81% of total confirmed cased. The top clusters included these types of groupings or locations:

  • Office workplaces*
  • Churches**
  • Internet cafes
  • Medical facilities***
  • Nursing/Long-term care facilities
  • Schools
  • Travel Groups
  • Fitness Gyms

Recent spikes: people have started to prematurely move more between Daegu and Seoul so there has been an increase in cases in Seoul.

*specific examples: call center, a local provincial govt office, kindergarten school

**the Shincheonji religious group is approximately 40% of the total cases in Korea and was the largest cluster.

***several hospitals were temporarily shut down due to infected people walking into ERs, rather than at scheduled and proper entry points, and spreading the virus to hospital staff.

Testing Criteria

The healthcare system and government communicated a clear set of criteria and symptoms for residents to understand and self-report for testing.

There were four approved and recommended types of people who should get immediate testing for COVID-19:

  • Anyone who has visited China and showing symptoms in last 14 days
  • Anyone who has come in direct contact with a confirmed person with COVID-19 and is showing symptoms in last 14 days
  • Anyone who has been referred by a licensed doctor to test for COVID-19
  • People who are members of or related to the Shincheonji church group

These tests are free and are done at Selective Care Centers. No home kits were made available — unclear that they were made or even exist. In addition, there are over 50+ ad hoc drive thru stations which were covered in news media which were effective in keeping potentially infected people safely separated from the healthcare staff and rotating quickly in queue. Tests are then processed in one of 93 public and private labs. Results arrive in 1–3 days and are communicated by phone/text.

Drive Thru Testing Centers using nasal swabs and remote diagnostic labs

Undocumented immigrants are also able to get tested without any reporting concern. This is something I hope we will do in the US as well, as its beneficial for everyone.

In 8 weeks, 307,024 people have been tested as of 3/19/20 in South Korea.

If the person tests positive for COVID-19, then they are isolated in a negative pressure rooms at a hospital or clinic to prevent any droplets/aerosol to make it outside of the room inadvertently.

If one doesn’t match one of the four criteria above, that person can still get tested, but if their results show them as “negative” for COVID-19, then they must pay 160,000 KRW ($130 USD) for the test. The test is free regardless of result if they fit the testing criteria

Distributed Network Testing, Quarantine/Isolation, and Contact Tracing

This defined process and creative setup helped keep the epidemic in check and limit damage to healthcare infrastructure and staff.

After examination, before they get the result, patients are required to stay at home for 14 days. During the quarantine period, a healthcare center staff delivers necessary supplies such as hand sanitizer to the front of the house. For violating the 14-days quarantine rule, a fine of 3 million won was imposed (equivalent to $2400 USD). The law has been revised due to the recent COVID-19, resulting in a fine of 10 million won (equivalent to $8000 USD)

If the result is negative, they will be released after 14 days of quarantine, but if positive, they will be immediately taken to the designated hospital. Also, If positive, Center for Disease Control identify the infected person’s movements through the interviewed statements of the infected person, CCTV, mobile carrier-provided location info, and the history of his/her credit cards. Then CDC notice the infected person’s movements to the residents of all municipalities via disaster text, without disclosing the name identity of the infected person. Citizens who matched the routes receive requests for examinations from the CDC and the Selective Care Center.

The clever set up of drive-through clinics in parking lots and major roadways enabled rapid and inexpensive implementation across the country. These stations reduced the test time from 30 minutes to 10 minutes, minimizing the risk of infection, and created significant gains in the total tests per day metric.

Korean Healthcare System Overview

South Korea is roughly the size of California with 51.5M people.

South Korea’s Single-Payer Universal Healthcare system allowed for relatively standardized tools and staff quality across the country, and continually updated virus and patient data across the clinics and pharmacy system.

  • 512 hospitals and clinics around the country.
  • 66 of these locations are designated as Selective Care Centers. This helps isolate testing and treatment and doesn’t affect other hospitals and clinics.
  • 93 labs around the country that can provide pathogen testing.
  • 20,000 tests performed per day as of March 12
  • 12 hospital beds per 1000 people which is ranked number 2 in the world. By comparison, the US is 3 beds per 1000 people and is number 32 in the world.

Technology: Communication, Contact Tracing, and Supply Rationing

Use of internet messaging, public data transparency, and a centralized digital healthcare data network helped tap into creating less panic and more self-guided prevention. They were prepared because of the MERS epidemic of 2015.

Because of the nation’s experience with MERS-CoV outbreak in 2015, the healthcare system in South Korea has been prepared for a quick epidemic response as well as an immediate transparency strategy with the public. During the MERS outbreak which killed 35 people, they gave limited information to the general public to reduce anxiety, and there was massive public and political fallout afterward for the government.

Re: COVID-19, they were able to create a test for COVID-19 and update all the labs with new protocols in 17 days. Also, the Korean CDC published daily data about cases, releases, isolations, and fatalities by age, gender, and city.

Government has been operating centralized communications with residents, via mobile texting and messaging constant updates of new cases or outbreaks to residents by the city subdistrict govt. Each district has its own website and residents can get updates.

Contact tracing was performed and routes and timelines were posted online of any new cases’ (name is shielded; age and gender shown) whereabouts over the past 2–3 weeks in one’s district, so that one can see if they might have come into contact with them and also to potentially avoid the specific places visited until sterilized. This has had some controversy.

In Korea, the government, epidemiologists, and doctors all agree that masks do help prevent spread of COVID-19, but with undersupply, they have installed a rationing program for masks with a network of approved pharmacies. To buy one, you have to use your Social Security Number and you are limited to two per person per week. This is centralized in their cloud-based computer system across every pharmacy as mandated by the national government, as is all patient data and diagnostic activity. Having a modern data sharing system in healthcare has proven to be a key benefit to moving quickly and at high performance in the case of epidemic response.

Naver, a major consumer internet company in Korea, created a “Find A Mask” mapping app to show where government-approved pharmacies have available rationed masks to prevent people from traveling to each pharmacy until they find one.

Similar to the previous case with MERS, civilian app developers created useful tools to help contain the epidemic. As the COVID-19 spread intensively in Daegu, two middle school seniors in Daegu created a website called “Coronanow”, showing the status of the confirmed patients and their travel history in a visualized map. In addition, a recently launched “Corona-ita” website shows the places that the confirmed patients have visited. It also shows the level of instability of any location, measured by the number of confirmed-cases-visited-places in the neighborhood. As the mask shortage intensified, civic developers and university students released ‘Mask-nearby’, which shows the status of government-provided masks in each pharmacy on the map.

Some SaaS companies in work collaboration space are offering free solutions to companies: mainly using AfreecaTV which is a local startup operating a popular paid group live video service and Google Meet/Hangouts.

*In South Korea, the social security number ( is used as a relatively strong unique identifier and has been digitized into the financial, consumer, and healthcare systems. In theory and in some practice, the government has the ability track at high-level consumer activity. Unclear as to the depth of this data monitoring.

Community Awareness

Media and local awareness of details is at 100% due to constant mobile loudspeaker updates and warnings to stay at home and socially distance unless necessary. Health instructions and self-quarantine recommendations are posted on buses, subways, buildings, outdoor advertising, TV, and signage. Visibly, N95 masks, hand sanitizers, gloves, and other personal hygiene protocols have become drilled into everyones daily lifestyle. By comparison, we don’t see this type of information campaign in media and public life.

Local Transportation, International Travel, and Freight

Ridesharing such as Papa and KakaoBlack, and local Taxi services are still operational, but demand is expectedly very low due to Social Distancing being in effect. Any carpool ridesharing features are currently not permitted.

International and domestic passenger travel is down 95%+.

Air freight is up by 20%. Truck freight volumes seem stable.

Regarding international travel, China and Japan banned Korean entry into their countries. 105 countries currently still ban entry from people coming from Korea. Korea has only banned visitors from Japan (latest in the Japan-Korea political war of words and policies) and people who are coming from the Hubei province in China

In the past two weeks, a majority of new imported cases found in Korea are now from Europe and North America. In prior weeks, the new imported cases were from China.

This is the most recent travel advisory and quarantine policy from Korean CDC:

In light of the recent rapid rise in the number of COVID-19 cases in Europe, the U.S., and the Middle East region, as well as the rise in the number of imported cases found both at airport quarantine and in communities, the KCDC announced that the Special Entry Procedure has been extended to all travelers arriving at port beginning at 0:00 of 19 March. Upon entering Korea, all travelers are required to respond to a questionnaire, get checked for fever, provide a domestic address and confirmed contact information at port entry, and report their symptoms daily for the next 14 days via the self health check mobile app (“Self-Diagnosis”) on their mobile device. Travel histories of all travelers entering Korea will be provided to healthcare providers via the International Traveler Information System for reference. The names of all entrants will be provided to local public health centers for a more active monitoring of potential imported cases for the first 14 days upon their arrival.

The KCDC also strongly recommended that all non-urgent international travel plans be canceled or postponed. Persons who are unable to avoid traveling for a critical reason are advised to refrain from visiting any enclosed facilities or healthcare facilities. Upon entering Korea, they should voluntarily disclose any symptoms and their international travel history and follow appropriate guidelines and instructions, including minimizing movement and interpersonal contact for 14 days. In particular, the KCDC urged travelers arriving from Europe or the U.S. to strictly follow the self-quarantine protocol, in light of the recent rise in confirmed cases in these regions.

Restaurants, Groceries, and Food Delivery

Restaurants down and in trouble across the board. Unclear to what level, as many of the small and chain food businesses are converting largely to delivery and take-out sales, but many are near-empty. Interestingly, restaurants are not shut down by government and some are still open for seated dining. Health and safety standards have been raised. Grocery stores are open for brisk business. [update 3/23: some restaurants and cafes are starting to seeing traffic again, but seen by many in public and press as premature as daily new cases have been increasing in past week.]

Pickup and delivery services (similar to Uber Eats and Postmates here in US) are maxed out but operational — two hour delivery times at lunch and dinner times. Food delivery services have been essential to households staying fed and abiding by self-quarantine policy.


Schools (elementary, middle, high school) are postponed until March 23 and may be pushed back to reopen in April.

Universities have changed the start date of the semester from March 2nd to March 16th and even conducted an online class via Zoom, Youtube, or its own online lecture system for two weeks after starting the semester so that actual meeting class should start in April. Until then, all classrooms are closed after 6 p.m.


Almost all companies from small to large companies have instituted Work From Home policy.

Corporate seminars, conferences, and certification tests scheduled for late February and March have all been canceled and have been postponed until April.

Religious Facilities

Church and cathedral services have been replaced by online worship via YouTube Live. A lot of public pressure has mounted against church groups, as the largest clusters have been more extreme church groups who have ignored government rule of no large group events.

Current Statistics

Korean outbreak statistics by city, region, age, and gender — from the Korean CDC and updated daily as a “press release”:


Korean outbreak data compared with World data by region. Very comprehensive and collects data in realtime from different sources such as WHO and different countries’ published data. Use google chrome browser and use copy translator feature to read:


What Can We Learn From The Korean Approach?

To flatten the epidemic curve and not incapacitate their healthcare system, the Korean government and healthcare system were prepared to deploy a Suppression strategy, not just a Mitigation strategy:

High Availability and Access to Testing, combined with immediate Isolation & Treatment. Special Care Center facilities were immediately converted or created as a pop-up immediately across the country. No rationing of tests between young and old — young asymptomatic cases can spread the virus. Quarantine during test diagnostics and then isolated clinical treatment if tested positive. The communication of clear criteria for testing helped create a proactive self-reporting flow of people into the testing workflow across the country. This was the number one priority for the government and healthcare system in Korea.

Extreme Social Distancing. Communicate widely a clear policy of testing procedure, self-quarantine, case isolation, upgraded personal hygiene, in a pervasive way that the public could understand. Without this, even the modern and well-prepared Korean healthcare infrastructure would have been overloaded and the number of cases and the case fatality rate would possibly have been much worse.

Contact Tracing. This was performed immediately with positive cases, leveraging a combination of patient interview, mobile, CCTV video, and credit card records for people for the purposes of informing people about whether or not they should get tested and which places to avoid temporarily. This enabled people to guide themselves and prevent new spreading or clusters, as well as reduce panic emotions of not knowing where outbreaks were happening.

No shutdown of commercial retail business and trade. So far, South Korea has avoided the forced isolation of all civilians and shutdown of industry manufacturing and consumer retail/restaurant industry, which would be crushing to an economy already in a recession. This was made possible by immediate and comprehensive testing, isolation, and treatment protocol.

*some of their data tracking and publishing techniques may not be readily accepted here in the US due to personal privacy issues.

In the US, these are some of the questions for us:

  • How do we instill a collectivist and responsible mindset toward heightened personal hygiene, self-reporting testing, and social distancing? (mixed messages here right now from media, local governments, CDC, White House, and WHO)
  • Who should get tested and how do you actually get tested without getting others infected, when capacity is unclear?
  • How do we get to 128,000+ tests per day in the US with an appropriate number of negative pressure room beds for infected cases? Assuming a population-proportional amount of daily testing is needed (20k test/day at 51.5m pop in KR), then the US would need to perform 128,000 tests per day, and properly isolate all infected cases at a hospital or clinic, to flatten the curve here.
  • How do we get more hospital beds? Negative pressure rooms? Ventilators? Masks? Should we convert more clinics to focus just on treating Covid19 patients? Should we building these from the ground up rapidly as China has done?
  • How can we protect the health and safety of care providers as the healthcare infrastructure becomes overloaded? Many hospitals and clinics were shutdown after case patients had infected the staff there in Korea.
  • With FDA approval required on home kits, CLIA-certified lab requirements for diagnostics, and a low number of beds per 1000 people, how do we scale to quickly test, treat, and trace effectively?
  • Where are the local outbreak clusters happening? What locations did infected people visit?
  • Will the food and medicine supply chain and retail be functional? State and local government should help restaurants, grocery stores, and pharmacies stay operational. How quickly can federal/state/local govts give financial support and subsidy to keep these critical employees paid and solvent?
  • Are we prepared to use Contact Tracing methods? How do we centralize and make transparent daily information published online or sent via mobile apps/sms to all residents? How do we arm everyone with information and provide some level of assurance that the government and healthcare system are functional and responding to the crisis?
  • Can we keep our commercial and retail industries operating during a period of extreme social distancing? How does this change our way of life long-term if we will have to be concerned about subsequent waves of infection as we’ve seen from any number of possible clusters?
  • Until an efficacious therapeutic or vaccine is available (est. 12–18 months), should we capitulate to a full lockdown which would drive our economy downward, or can we implement a plan similar to the Korean approach and use a functional suppression strategy across every state in the US and every country?

investor, entrepreneur, and true believer. founder/managing partner at @kindredventures.

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