PHWR Public Health Weekly Report

Coronavirus disease 2019 (COVID-19), first reported in Wuhan, China, on November 17, 2019, caused a global pandemic with the global cumulative confirmed cases exceeding 700 million and cumulative deaths exceeding 7 million [1]. Accordingly, the Korea Disease Control and Prevention Agency (KDCA) invested efforts toward acquiring COVID-19 vaccines for public vaccination. At the time, vaccines were still in developmental stages, hence the high uncertainties about their efficacy, safety, and development status. Nevertheless, the Korean government monitored the vaccine development status and clinical trials overseas while also supporting similar domestic efforts. From July 2020, government negotiations with pharmaceutical companies for vaccine pre-orders commenced, which prompted the establishment of the legal basis for pre-ordering (Infectious Disease Control and Prevention Act) and resulted in the pre-ordering of a sufficient amount of COVID-19 vaccines for the public in the Republic of Korea (ROK) [2]. On February 26, 2021, the country’s vaccination campaign against COVID-19 began, and this required safe storage for COVID-19 vaccines, which have very demanding management conditions, and a rapid distribution system. Among the COVID-19 vaccines introduced in ROK, mRNA vaccines, which were the main vaccines, needed to be transported under cold chain conditions. In addition, because the handling of coronavirus vaccines are specific such as thawing frozen vaccines and dividing them into smaller quantities, the storage and distribution system used exclusively for COVID-19 vaccines should consider the characteristics of each type of vaccine, and the infrastructure and expertise of existing distribution companies should be used as reference. This report describes the details regarding the distribution system established for COVID-19 vaccination to protect the public after the COVID-19 outbreak.

Establishment of COVID-19 Vaccine Distribution System

The COVID-19 vaccine storage and distribution system was established through collaboration at a pan-government level. This included participation from relevant ministries including the Ministry of Food and Drug Safety (MFDS), Ministry of National Defense (MND), and Ministry of Land, Infrastructure, and Transport (MLIT), to ensure rapid and safe transportation of imported vaccines to the vaccinating institutions and prevention of accidents that may occur during the transport process. MFDS was responsible for vaccine management guidelines for maintaining cold chain conditions during storage and distribution. Meanwhile, MND was responsible for setting up a transport support headquarters to oversee control and response to situations throughout all the stages of vaccine distribution, from mock training to actual transport and escort procedures. MLIT and Korea Customs Service vaccine established a support system to expedite air transport and customs clearance of vaccines. In addition, the Ministry of Trade, Industry, and Energy and Public Procurement Service were responsible for identifying the latest status of vaccination-related goods and assisting in the purchase contract processes (Table 1) [2].

Table 1 Key considerations for establishing a coronavirus disease 2019 (COVID-19) vaccine storage and distribution system

Key point	Detail	More detail
Cooperation	Ministry of Food and Drug Safety	Cooperation in enacting guidelines for vaccine management related to distribution and storage, etc.
	Ministry of National Defense	Control and response to the entire stage of vaccine distribution through the formation of transportation support headquarters
	Ministry of Land, Infrastructure and Transport/Korea Customs Service	Establish a fast support system for vaccine air transport and customs clearance
	Ministry of Trade, Industry and Energy/Public Procurement Service	Understanding the current status of inoculation-related items and cooperation in purchasing contracts
Support	Local government	Support for inoculation-related items such as ultra-cold freezers and digital thermometers
Distribution agreement	2021	SK Bioscience, GC Biopharma (an estimated contract)
	2022	GC Biopharma (a definitive contract)
	2023–2024	HLB Therapeutics (a definitive contract)
Vaccine convoy	Carrying out a military police convoy	The airport ⟶ logistics center ⟶ regional center ⟶ medical institutions: carrying out a military police convoy
Cold chain	Storage temperature management	Unlike other vaccines, ultra-low temperatures and frozen vaccines are required to be stored, so a dedicated logistics center is established
	Control system	IoT-based integrated control system
	A shipping container	Conducting a transport container qualification assessment and providing an internal automatic thermometer
System	Utilizing the COVID-19 vaccination registration system	Prepare and utilize vaccine applications and supply systems

In 2021, when COVID-19 vaccinations began, there were no standards or previous data regarding the scale of quantities that needed to be distributed. Accordingly, agreements were made based on contract by rough estimate, a type of contract in which the contract was entered into by making a rough estimate of the contract amount when the exact amount cannot be determined in advance. The contract is then settled after the performance of the contract has been completed. Considering the expertise and urgency of distribution, multiple distributors (SK Bioscience and GC Biopharma) were selected to ensure that the vaccines could be distributed more, according to the characteristics of the vaccines being distributed and ease of storage. Based on experience from 2021, the distribution of COVID-19 vaccines became more stable in ROK in 2022. Accordingly, agreements were made by fixed-price contract, instead of contract by rough estimate, and with just a single distributor (GC Biopharma) through technology assessment. In addition, the same method was applied to select a single distributor (HLB Therapeutics) in 2023 and 2024 (Table 1).

Vaccine Distribution Process

For the nationwide allocation of COVID-19 vaccines introduced in ROK, medical institutions requested the quantities of each vaccine needed on a weekly basis, and KDCA confirmed the quantities after review and approval by public health centers. Initially, the vaccines were allocated manually (i.e., via email), but from February 2022, requesting vaccines became more convenient as medical institutions throughout ROK were able to make their requests through the “COVID-19 vaccination registration system” established by KDCA. The final allocation quantities confirmed through the system were sent to the distributor, who then established a delivery plan for the following week. This plan was shared with city/provincial officials to ensure no disruption in the delivery. The confirmed delivery plan included thawing (2 days prior to delivery) and subdivision/packaging (1 day prior to delivery) for delivery under cold chain conditions directly to contracted medical institutions and public health centers (Figure 1) [3,4]. In the early stages of vaccine delivery, military and police escort were used from the time that the vaccines arrived in ROK via air transport, to when they were delivered to the vaccination centers, to ensure stable distribution and without theft or traffic accidents. Subsequently, the escort was lifted step by step in the order of medical institutions–regional hubs–integrated logistics centers–airport by comprehensively considering the vaccine supply situation, vaccination rate, and adjustment of infectious disease grade. Since the vaccination campaign began, 96.79 million, 34.11 million, 18.51 million, 1.4 million, 1.6 million, and 190,000 doses of Pfizer, Moderna, AstraZeneca, Janssen, Novavax, and SKYCovione vaccines, respectively, have been delivered throughout ROK. This has enabled each vaccination center to provide vaccinations with each type of vaccine through advance and same-day appointments (as of August 31, 2024).

Figure 1. Coronavirus disease 2019 vaccine distribution process
OEM=original equipment manufacturer.

Distribution Maintaining Cold Chain Conditions

Typically, regular vaccines are stored and transported under refrigerated condition (2℃ to 8℃), but among the COVID-19 mRNA vaccines, the Pfizer vaccine requires cryogenic storage (–90℃ to –60℃) and the Moderna vaccine requires freeze storage (–50℃ to –15℃). Pyeongtaek Integrated Logistics Center, the only cryogenic warehouse in ROK, was established and used as a dedicated logistics warehouse for the storage and distribution of COVID-19 vaccines. Temperature management is very important for COVID-19 vaccines as frozen vaccines must be thawed and delivered to the vaccination centers under refrigerated conditions (2–8℃). In addition, these vaccines require cold chain distribution to ensure that they are kept cold enough to prevent structural damage to the vaccines and to ensure that the vaccines retain their efficacy, from production to delivery. Therefore, to ensure that each type of vaccine is kept at its designated storage temperature before thawing and transported under set temperature conditions after thawing, the entire process from storage to delivery was linked to temperature equipment and an IoT-based integrated control system to maintain cold chain conditions. For vaccine transport, qualification must be performed on the transport container and records must be kept, while an automatic temperature sensing system is placed inside. Moreover, a transport plan, including information regarding the type of refrigerant inside the transport container, amount added, and precautions during transport, must be attached, while response guidelines for delays in transport, vaccine temperature deviation due to abnormalities in the transport container or vehicle, and theft or loss of vaccines must be prepared to ensure that the cold chain conditions are strictly maintained (Supplementary Figure 1; available online) [5]. For this, KDCA created the framework for domestic vaccine storage and distribution by establishing the “COVID-19 Vaccine Storage and Transport Management Guidelines” (January 2021). These specify details regarding safe storage and distribution of vaccines from when the vaccines are introduced into ROK to the completion of transportation to the vaccination centers. They are based on the Pharmaceutical Affairs Act and MFDS approvals regarding the handling of COVID-19 vaccines for the storage, handling, and distribution of COVID-19 vaccines introduced to ROK for the first time.

The previous section discussed cold chain distribution, from the integrated logistics center to vaccination centers, but it is just as important for vaccination centers to provide safe vaccinations by storing the vaccines without temperature deviation. For this, KDCA provided deep freezers to local COVID-19 vaccination centers operated directly by local governments in the early stages of the vaccination campaign, to ensure that the frozen Pfizer vaccines could be safely stored and managed. In addition, the vaccination centers were provided with digital thermometers to prevent vaccine temperature deviation and on-site inspections of vaccination centers were conducted to strengthen the management and supervision of vaccine storage conditions. This was to ensure that the public was being vaccinated with safe vaccines that have been kept under cold chain conditions.

Utilization of COVID-19 Vaccination Registration System

With the emergence of the need for a vaccination reservation and registration system due to the COVID-19 pandemic, the “COVID-19 vaccination registration system” was developed, including a distribution system. From the early stages of supplying the COVID-19 vaccines, KDCA established delivery plans by relaying the allocation of vaccines for each vaccination center to the distributor through the “Vaccine supply management” tab in the COVID-19 vaccination registration system [6]. Vaccine inventory and the amount used in each public health center and vaccination center were monitored and statistically managed through the system for real-time monitoring and transparency in vaccine use. In 2022, the “Vaccine request management” tab was newly created to upgrade the system to allow each vaccination center to make the request directly through the system, rather than the previous method of doing it manually (i.e., via email). In the early stage of the vaccination campaign, the demand for vaccines requested by medical institutions were reviewed by public health centers and reviewed again at the city/province level before KDCA allocated the vaccines after a final review. Subsequently, the city/province review was eliminated in response to the changing vaccination environment, such as decrease in vaccination demand and infrastructure. Moreover, the system was upgraded to enable requests for allocation and delivery to be made, step by step, by linking the “Vaccine request management” and “Vaccine supply management” tabs together to make the COVID-19 vaccine allocation and distribution tasks more effective and efficient.

Local Government Cooperation and Support

For seamless distribution, communication with cities/provinces and public health centers through official notices and real-time messages was strengthened to ensure adequate supply of COVID-19 vaccines needed by each local government. In case of urgent situations, such as unexpected increase in vaccination demand, additional deliveries were made by coordinating with the distributor. In addition, when deliveries were delayed during holiday period or due to weather conditions (e.g., typhoons, heavy snow), local governments were notified immediately, to minimize inconvenience. In addition, all efforts were made to ensure safe and smooth vaccination by strengthening measures to prevent disruption in COVID-19 vaccine distribution, including having contingency scenarios available at the distributor in case of any emergency.

In the early stages of the vaccination campaign, frozen Pfizer vaccines were delivered to vaccination centers, which required deep freezers to store the vaccines at ultra-low temperature conditions. Accordingly, KDCA provided national subsidies to local governments at the municipal and provincial levels to purchase and use deep freezers and uninterruptible power supplies. KDCA also provided national subsidies to purchase digital thermometers to allow contracted medical institutions to manage COVID-19 vaccines at appropriate temperatures (2–8℃). Moreover, national subsidies were also provided for diluents as the initial Pfizer vaccines needed to be diluted with physiological saline. Furthermore, with the international COVID-19 vaccine supply being unstable, the Korean government purchased, in bulk, low dead space syringes, which are manufactured to inject the maximum amount of medicine compared with regular syringes to vaccinate as many people as possible. They supplied them to local governments, which helped to make vaccinations more convenient while also being cost effective (Supplementary Figure 2; available online).

This report described the overall flow of distribution and aspects that required pan-government and local government cooperation in establishing the COVID-19 vaccine storage and distribution system. The report also examined safe vaccine distribution from the integrated logistics center to vaccination centers, with recognition of the importance of maintaining cold chain conditions, and efforts made by KDCA for maintaining cold chain conditions at vaccination centers. In particular, among the COVID-19 vaccines, mRNA vaccines were developed because of the large-scale pandemic, and since mRNA vaccines are a new type of vaccine, different from viral vector and synthetic antigen vaccines, stringent standards were applied when establishing the distribution system. Furthermore, as storing and transporting mRNA vaccines presented many challenges, cold chain conditions were established and operated more thoroughly to ensure safe delivery of biopharmaceuticals during this pandemic. The COVID-19 vaccine distribution was more difficult than the distribution of existing vaccines. For example, to strictly maintain cold chain conditions, a control system that can monitor temperature throughout the delivery process was set up at integrated logistics centers, and for immediate notification upon temperature deviation, automatic temperature recording system were installed. These steps required a significant amount of human and financial resources. Therefore, the distribution system for COVID-19 vaccines is expected to play a complementary role in establishing another response system in the event of a new epidemic. In recent years, outbreak of other viral epidemics, such as severe acute respiratory syndrome, H1N1 influenza, and Middle East respiratory syndrome, occurred in 4–6 year cycles, with infectious disease experts warning that large-scale epidemics occur cyclically. While a rapid distribution network can be proposed, pan-government cooperation, not just the competencies of single institutions, is crucial to establish a fast distribution network. For example, the COVID-19 vaccine storage and distribution system was made possible through the cooperation of MFDS, MND, and MLIT. Unlike most vaccines that can be stored under refrigerated conditions, some COVID-19 vaccines needed to be stored in deep freezers. Thus, vaccines to be used in the next pandemic may also have different storage or distribution temperatures, so it is necessary to establish dedicated logistics warehouses that can store vaccines at appropriate temperatures and supply chain considering cold chain conditions according to distribution temperature. We hope that this report will be helpful in establishing a vaccine supply chain in a timely manner and protecting the public from the infectious disease when a new epidemic strikes in the future.

Ethics Statement: Not applicable.

Funding Source: None.

Acknowledgments: None.

Conflict of Interest: The authors have no conflicts of interest to declare.

Author Contributions: Conceptualization: JAK. Data curation: None. Formal analysis: None. Funding acquisition: None. Investigation: JAK, YJK, JWS, JKP. Methodology: None. Project administration: None. Resources: None. Software: None. Supervision: JWS, JKP. Validation: None. Visualization: None. Writing – original draft: JAK. Writing – review & editing: JAK, YJK, JWS, JKP.

Supplementary data are available online.