National Response to COVID-19 in the Republic of Korea and Lessons Learned for Other Countries

ABSTRACT In the first two months of the COVID-19 pandemic, the Republic of Korea (South Korea) had the second highest number of cases globally yet was able to dramatically lower the incidence of new cases and sustain a low mortality rate, making it a promising example of strong national response. We describe the main strategies undertaken and selected facilitators and challenges in order to identify transferable lessons for other countries working to control the spread and impact of COVID-19. Identified strategies included early recognition of the threat and rapid activation of national response protocols led by national leadership; rapid establishment of diagnostic capacity; scale-up of measures for preventing community transmission; and redesigning the triage and treatment systems, mobilizing the necessary resources for clinical care. Facilitators included existing hospital capacity, the epidemiology of the COVID-19 outbreak, and strong national leadership despite political changes and population sensitization due to the 2015 Middle East respiratory syndrome–related coronavirus (MERS-CoV) epidemic. Challenges included sustaining adequate human resources and supplies in high-caseload areas. Key recommendations include (1) recognize the problem, (2) establish diagnostic capacity, (3) implement aggressive measures to prevent community transmission, (4) redesign and reallocate clinical resources for the new environment, and (5) work to limit economic impact through and while prioritizing controlling the spread and impact of COVID-19. South Korea’s strategies to prevent, detect, and respond to the pandemic represent applicable knowledge that can be adopted by other countries and the global community facing the enormous COVID-19 challenges ahead.

In the first two months of the COVID-19 pandemic, the Republic of Korea (South Korea) had the second highest number of cases of any country, following only China.Despite this initially high burden of disease, South Korea was able to dramatically lower the incidence of new cases and sustain a low mortality rate, making it a promising example of a strong national response.After February 18, 2020, when the 31st case in the country was confirmed, massive population clusters arose in the city of Daegu and the surrounding areas.By the last day of February, the incidence of new cases peaked at 909 confirmed cases per day, with the rate of new cases slowing to approximately 100 new cases per day by mid-March 2020.During this time, the country achieved a low case mortality rate (111 deaths/8,961 confirmed cases, as of March 23, 2020; crude fatality rate [CFR] = 1.24%).By comparison, China had a much higher mortality rate (3,276/81,601; CFR = 4.01%; Figure 1).At the same time, the pandemic was surging around the world, with many countries also reporting higher mortality rates, such as Italy (5,476/ 59,138; CFR = 9.26%), Spain (1,720/18,572; CFR = 9.26%), Iran (1,685/21,638; CFR = 7.79%), France (674/ 15,821; CFR = 4.26%), and the United States (402/31,573; CFR = 1.27%). 1 Importantly, South Korea achieved this control and mortality rate with a relatively blunted economic impact given the extent of the outbreak when compared with other Asia Pacific countries with lower early COVID-19 burden. 2 As the pandemic continues to spread, understanding the lessons learned from South Korea's national COVID-19 response strategy is critical for countries who are already affected by COVID-19 and those still planning their response to the pandemic. 3We aim to describe key elements of South Korea's national response, focusing on measures that may have contributed to reducing the surge in incidence ("flattening the curve") and minimizing economic collapse.Key features of the response to date included specific strategies and strong national leadership and work to ensure effective coordinated and intersectoral response.The strategies included the following (Table 1): • Early recognition of the threat and rapid activation of national response protocols led by national leadership; • Rapid establishment of widespread diagnostic capacity; • Scale-up of measures for preventing community transmission, including contact tracing, quarantine, and isolation; and • Redesigning the triage and treatment systems and mobilizing the necessary resources for case management.
Below we discuss each of these features, including how they were influenced by the nature of the epidemic, followed by a discussion of challenges to date and lessons learned thus far.

South Korea's COVID-19 Response
Early Recognition of the Threat and Rapid Activation of National Response Protocol From the time of first case onset on January 20, 2020, until February 18, 2020, there were only 31 new cases, but the incidence rose rapidly to a maximum daily count of 909 identified new cases on February 29. 4 During that week the government of South Korea activated high-level national response protocols to ensure a cross-society and pangovernmental approach to containing the pandemic.The response was informed by epidemiological evidence that the majority of South Korea's initial pandemic was linked to the 31st confirmed patient.Confirmation that the 31st patient was the locus of the epidemic was enabled because of meticulous contact tracing and effective surveillance with rapid feedback of results.These dual processes allowed for rapid detection of the 31st case (diagnosed February 18) as the source with detection of a case surge from one to two per day to 15 on February 19 and increasing daily to 210 on February 23.This surveillance combined with careful contact tracing and case investigation also identified that a high proportion of the newly confirmed patients were from the same megachurch membership.On February 23, the Korean Centers for Disease Control & Prevention (KCDC) announced that 309 (55.6%) of the total 556 cumulative cases to date were members of the megachurch in Daegu city.Further data that emerged as a result of the ongoing contact tracing suggested that 5,051 new infections, or approximately 56.8% of the total confirmed cases as of March 22, 2020, were linked to this 31st patient. 4The detection of this novel cluster of patients from the megachurch led to a significant effort to increase national preparedness, in anticipation of a large rise in new cases (Table 1).This early recognition of the threat to come-given the incubation period between infection and disease onsetgave the government one to two weeks' lead time for preparedness and planning before the inevitable rise in cases. 5In their response, the Ministry of Health and Welfare and the President's Office developed a twotrack approach focused on (1) the public health response in order to prevent and detect further infections, including increasing diagnostic capacity and the scale up of prevention measures, 6 and (2) the clinical response to manage infections.

Rapidly Establishing Widespread Diagnostic Capacity
A key component of the government's response was to rapidly establish widespread diagnostic capacity across the country.This involved three primary interventions:  Building on this scaling of diagnostic capacity, several other key prevention measures were identified and rapidly scaled.Extensive contact tracing, including of the superspreader 31st patient, promptly led to the detection of several clustered cases (Table 2) during the last week of February.This contact tracing was accomplished by a rapidly established temporary workforce of Epidemiological Intelligence Service (EIS) officers. 6,7hese low-to middle-level employees were repurposed from governmental health center officers across approximately 250 districts (each of which includes a population of 50,000-500,000) and, though not fully qualified EIS officers, either had the competency or were quickly trained in standardized protocols for contact tracing. 7his multilevel response was particularly effective, with the central, provincial, and metropolitan governments' officers responsible for contact tracing in large clusters and public health centers and county officials handling contact tracing and quarantining in smaller clusters such as family units.The addition of this rapidly deployed workforce enabled South Korea's policy of "never give up" contact tracing.Such meticulous tracing led to earlier case detection than would have otherwise been possible.Continuous use of this strategy also seems to have kept the rate of new infections at a lower pace than that in most other countries impacted by the pandemic.
Although no specific clinical therapeutic intervention was provided to patients identified through early detection, lower crude fatality rates may have resulted from an ability to reduce the rate of infection among high-risk populations as a result of the early detection and isolation of cases, as well as through a flattening the curve approach that prevented hospitals from ultimately becoming totally overwhelmed and thus better able to manage the most severe cases with the resources available.
To prevent disease spread, individuals who were identified as having contact with either confirmed or suspected cases, as well as any individuals who had recently traveled to China or two affected local areas in South Korea with early epidemics, were quarantined at home or in designated support centers for two weeks or until they were confirmed to be clear of infection.Two-week quarantine in these public support centers was provided to individuals free of charge.Drawing from their experience with the Middle East respiratory syndrome-related coronavirus (MERS-CoV) epidemic in 2015, the Ministry of Health and Welfare, working with provincial/metropolitan governments, also activated one triage center per district for any individuals with a fever or respiratory symptoms (see below).The government discouraged all nonessential gatherings to achieve social distancing for the broader population, though this was not strictly mandated during the response period described.
Finally, South Korea implemented national isolation protocols that adhered strictly to the International Health Regulations, which did not entail closing national borders to travelers from affected countries. 8(South Korea did block inflow from Wuhan, China-the epicenter of the outbreak-but only after China also applied a lockdown to the same region.)Rather than close its borders, South Korea instituted a strict program of self-quarantine and contact tracing for all incoming travelers, including through a mandatory telephone software application.Additionally, as of the last week of March, South Korea has instituted a mandatory two-week quarantine for travelers from some European countries.The number of cases detected in quarantine increased from three between January 19 and January 25 to 321 in the last week in March, with the highest proportions coming from Europe and the United States.These cases represented six cases per 10,000 incoming travelers in January, increasing to 22 per 10,000 in February (the number of travelers for March was not available at the time of submission). 9The open border policy has been unpopular with some groups who have sought to blame imported cases as the cause of the domestic epidemic, 10 but the government has sustained a policy of "no blaming of the victimized population," in part to prevent a global and domestic economic downturn.

Redesigning the Triage and Treatment Systems and Resource Mobilization
In response to the outbreak, South Korea redesigned health service provision at the national level.These changes initially focused on the subnational epicenter to create two systems (COVID-19 health system versus non-COVID-19 health system) to both manage the outbreak and to work to ensure continuity of non-COVID related needs.The COVID-19 system included public quarantine, primary The response also allowed for early innovation to meet needs; for example, drive-through sampling for diagnosis was motivated in part to preserve PPE and limit health worker exposure during the sampling procedure, complementing the media focus on widespread rapid diagnosis.
Complementing this resource planning to prepare for the anticipated surge, South Korea applied China's severity mix profile as a reference for resource allocation ahead of the surge. 13The pattern of disease progression for COVID-19 in China per the severity mix reference was as follows: ( of the number of referral cases due to severity progression based on this reference rate that could be anticipated at the designated centers.Despite this planning, in the early phase, there were shortages in key elements, including PPE, negative pressure rooms, and health care workers at the center of the outbreak.These shortages were being addressed through national-level changes to patient flow and management of COVID-19 patients that started at the end of February.

Favorable Conditions Compared with Other Countries
The more favorable outcomes associated with the South Korea outbreak compared with other affected countries, such as the lower crude fatality rate and decreased rate of new infections, may also be influenced by several other contextual factors.The government structure and close relationship between the Ministry of Health and Welfare, with authority over the KCDC, ensured a science-based authority working at the highest level.This evidence and data-driven decision making was also facilitated by the presence of a health systems researcher as Chief Secretary for the President, overseeing the governance of all sectors including the health sector.As a result, the coordination between the Prime Minister's office, Ministry of Health and Welfare, and KCDC was very effective and facilitated a rapid and data-driven response including reallocation of resources in a relatively short time.Some of the success of South Korea's response may have been related to the experience of MERS-CoV in South Korea, where high numbers of fatalities due to MERS-CoV occurred in 2015: 38 deaths from 186 confirmed cases and an additional 16,752 suspected cases. 14,15During the six months of the outbreak, the South Korean people were living in fear under a threatened environment.The South Korean government experienced huge economic losses, including an estimated 2.6 billion USD lost in tourism revenue, 16 12 million USD on costs for MERS diagnosis and treatment during the outbreak, and 860 million USD from the central government's budget associated with MERS response activities.Key officials of KCDC who were responsible for this response, including the current KCDC director, were heavily criticized and seriously punished, although the level of punishment was subsequently reduced.This painful memory of the South Korean people and government officials might have triggered early, aggressive responses to the COVID-19 epidemic to prevent similar results and increased the willingness of the population to listen to and adhere to the advice of the government and public health officials.South Koreans may also have had a deep understanding of how important this collective action was to prevent the tragedy of mass contagion and preserve their safety.For example, a recent 2020 poll showed higher levels of individual adherence to the public prevention protocols recommended by KCDC and the central government compared to similar adherence during the period of MERS-CoV in 2015.
There are other enabling factors as well.For instance, the affected patients were more likely to be younger compared with those in China or Italy; lower fatality rates have been reported across many countries for those in younger age groups.However, age-specific case fatality rates were also a bit less severe in South Korea compared with other countries, with no deaths among individuals under the age of 30 recorded as of March 25, 2020. 9n addition, the number of hospital beds per population before the pandemic was much higher in South Korea than in many other high-income countries (about three times that of Italy and two to three times the Organization of Economic Cooperation and Development average). 17Although this situation has been criticized in the past and is associated with a predominance of private-sector hospitals, the higher number of beds required less flattening of the curve to remain below the hospital system capacity threshold.These extra beds and the rearrangement of beds dedicated to COVID-19 and non-COVID-19 cases between hospitals resulted in more room within the system to flexibly respond to this new epidemic without sacrificing care for non-COVID-19 patients while simultaneously avoiding long waiting lists for COVID-19 patients requiring admission.
As noted, the government had discouraged all nonessential gatherings to achieve social distancing and, despite not being strictly mandated, most people voluntarily followed this recommendation until slowing of the incidence rate was achieved in the middle of March.The population was already aware of the risk from the MERS experience, which may have contributed to better adherence without the need for closure of businesses.South Korea also did not need to implement school closures because this period was during the typical winter break; however, the new academic year has been recently postponed from the usual start date of March 1.
Finally, most cases in South Korea were clustered in more specific confined areas than was the case in China or other countries .South Korean cases were related to a smaller number of larger, more socially structured clusters of transmission, including the megachurch member clusters as the largest one, other religious groups, a hobby sports group, and workers in a densely populated environment in the tele-communication center of a bank.As a result, it may have been more efficient to carry out the meticulous contact tracing through EIS officer team action than designing it would have been had cases been dominated by multiple smaller size clusters and community transmission as seen in other countries such as China, Italy, and Spain.

Challenges to Date
This success has not come without challenges.For example, in response to an urgent call from the Daegu Medical Association, many physicians and nurses volunteered to provide care in facilities with a high density of patients per medical personnel (in part due to the loss of some medical personnel resulting from COVID-19 infection).However, this influx of workers was not enough to meet workforce needs and was complicated by the exhaustive workloads with extended use of PPE and need to stay in nearby hotels instead of their homes for several weeks.Some of the challenges arose in part because neither the government nor the Korea Medical Association-despite being inclusive of most physicians in South Koreahave direct authority over the largely public-sector health workforce.In response, the government is considering establishing a legal framework for reallocating human resources for health during an epidemic.Additionally, despite forecasting, insufficient PPE supplies such as masks and gloves often became a problem at an institutional level.Finally, though South Korea has managed to slow the epidemic, experts still do not know how many sporadic cases are about to appear in communities and what newly imported cases may be arriving from other countries.The future of the pandemic in South Korea will continue to evolve, and time will show whether the government and society of South Korea will continue to contain the COVID-19 epidemic through existing or new strategies.

Lessons Learned
During this time when many countries around the world are just seeing the beginning of community spread as well as the potential of health care-related transmission of COVID-19, South Korea offers several important lessons, many of which can be implemented now.Most fundamental, South Korea recognized the problem posed by COVID-19 early and responded accordingly.All countries should now acknowledge the challenge and move quickly to implement the following lessons.

Establish Diagnostic Capacity
As quickly as possible and on the largest scale feasible, countries should work to build testing capacity and prepare mechanisms for deploying this testing outside of the usual health care system.This includes recruiting private-sector capacity as part of the national response.

Implement Aggressive Measures to Prevent Community Transmission, Including Meticulous Contact Tracing, Quarantine, and Isolation Supplemented as Needed by Physical Distancing Interventions
The meticulous contact tracing by the expanded number of local EIS officers was likely a critical factor in the successful results to date.This EIS-based workforce development may be a possible strategy to replicate in other affected countries.Other countries could begin now by training and utilizing out-of-work or underemployed workers, especially those within the health professions who may be experiencing reduced typical caseloads due to COVID-19, to lead and implement such a strategy in their countries.But this must be done with training and adequate PPE to protect this new workforce and ensure that they do not themselves become sources of spread.Even identifying contacts and simply informing them of their risk and the need for and how to implement strict isolation at home is important to mitigate spread.
In addition, identifying facilities to house patients who are in need of strict isolation and/or quarantine but are unable to do so at home may be helpful, while ensuring that appropriate care is available without undue additional expense to individuals.

Redesign and Reallocate Clinical Resources for New Environments
Governments should be looking at all available outpatient and inpatient health care facilities and identifying which are best suited for managing which types of COVID-19 cases and determining which facilities or sections should be preserved for primarily non-COVID-19 related primary health care.Governments should partner with private-sector facilities to make these determinations and provide necessary incentives to promote collaboration and compliance.Though South Korea was able to implement district-level triage (using local government health centers), redesigned primary health care triage is also critical for flattening the surge of incidence and mortality and effectively protecting health professionals.Though non-COVID-19 primary health care services were reduced, virtual consultations and prescribing were approved during the epidemic.If such measures are not implemented, a negative impact on treatment capacity for both COVID-19 and management of non-COVID-19 chronic diseases will appear quickly in affected countries.
Prioritizing the Control of Spread and Impact of COVID-19 Can Limit the Economic Impact Just as important to note are the strategies South Korea did not have to take, in part reflecting the success of strategies to prevent, detect, and respond.For instance, South Korea did not close its borders but instead focused on broad application of meticulous contract tracing and employed this strategy with travelers as well.In addition, through a greater focus on contact tracing and selective quarantine and isolation, they did not implement a large-scale population lockdown and closure of businesses now in place in many other countries.By adhering to the International Health Regulations, not only did South Korea show solidarity with the international community in addressing the pandemic but it likely reduced the economic shock-and potential resulting additional health impacts-that would typically occur.

Conclusions
A two-track approach to harmonizing strategies through both clinical services (health system redesign through reallocation and prioritization of treatment resources to align with increased demand) and public prevention measures (quarantine, contact tracing, and isolation) were critical and should be quickly considered for application in other affected countries.This approach was facilitated by both decisive central leadership and a strong decentralized system open to the repurposing and flexible reallocation of resources and depended on political leadership and a commitment and willingness to try innovative responses.Many of these responses reflect important activities that included but went far beyond changes to care delivery, such as governance, surveillance, community engagement, supply chain management, and rapid use of data for developing and adapting strategies. 18Our hope is that by explicating the strategies to prevent, detect, and respond from South Korea, transferable and applicable knowledge can be adopted by other countries and the global community facing the COVID-19 challenge.

( 1 )
Establishment by the leadership of the KCDC of public-private partnerships for the rapid development of novel diagnostic tests using real-time polymerase chain reaction (PCR) technology; (2) Expedited approval by the Korean Food and Drug Administration for the use of these tests for suspected cases; and (3) Rapid deployment of these tests throughout the country in partnership with local governments.

Table 1 .
Timeline of National Policy and Strategy Implementation to Tackle COVID-19 Epidemic-Pandemic in South Korea

3
South Korea's early and rapid expansion of testing relied on the rapid engagement of the private sector and approval of tests by the Korean Food and Drug Administration.This rapid availability of tests as well as the aggressive use of contact tracing is shown in Figure2, reflecting an increase from 1,581 test results per day on the day after the 100th case was reported to 11,290 per day on April 1.We used a starting date of the 100th case rather than calendar dates to allow for comparisons between South Korea and the United States from the respective starting times of the epidemic based on data availability from the United States.The strategy of rapid testing scale-up and the use of meticulous contact tracing (below) facilitated earlier and more effective containment of viral spread compared with other countries such as the United States, where scale-up of diagnostic capacity after the 100th case occurred later and with much more limited use of contact tracing.Reflecting these differences, South Korea had much lower cumulative positivity rate (ratio of positive to negative tests) compared with the United States (2.9% versus 17.4%, respectively, 19 days after the 100th case), as well as daily positivity rates at that time (2.9% versus 25.7%, respectively).In South Korea, positivity rates have continued to decline (101 of 11,290 [0.9%] of tests on April 1, 2020), reflecting the sustained strategy of aggressive testing.Scale-Up of Measures to Prevent Community Transmission, Including Local Contact Tracing, Evaluation Through Local Screening Centers, Quarantine and Isolation, and Limited Physical Distancing

Table 2 .
7onfirmed COVID-19 Case Distribution in the Republic of Korea (as ofApril 5, 2020)This includes some health care workers without known contact through the megachurch, but specific data on potential nosocomial transmission were not available.Source: Constructed using data from the Korean Centers for Disease Control & Prevention.7healthcare triage and admission for observation at the primary care level accommodation support centers staffed by health care workers, and transfer to secondary hospitals and tertiary hospitals based on severity of illness.This strategy included a national-level coordination center that managed the flow of COVID-19 patients to hospitals or, if needed, to other provinces.The restructuring also included diverting the flow of patients with non-COVID-19 condi- a