SK Bioscience Flu Vaccine Returns After 3 Years... Launching Supply of 5 Million Doses

Visiting Andong L House Vaccine Production Base
Influenza Vaccine 'SkyCellflu' in Full Shipment Preparation
World's First Cell-Cultured Quadrivalent Influenza Vaccine
Production Resumes After 3 Years... Shipment Starts on 23rd

On the afternoon of the 22nd, I visited SK Bioscience's L House in Andong, Gyeongbuk. At this vaccine production base of SK Bioscience, inspection and packaging work for the influenza (flu) vaccine 'Skycellflu,' which is about to be shipped, was in full swing. The process of filling the vaccine bulk solution, which has completed the production process, into prefilled syringes (PFS) and turning it into a formulation was mostly mechanized and carried out automatically. The employees in charge of inspection and packaging focused on their respective tasks, paying no attention to the gathered press. On the 22nd, a day before the shipment of Skycellflu, I visited L House to observe the production and quality control (QC) processes.

Inspection work for the influenza vaccine 'Skycellflu' is underway at SK Bioscience L House in Andong-si, Gyeongbuk.
[Photo by SK Bioscience]

SK Bioscience will resume shipment of the quadrivalent flu vaccine Skycellflu starting from the 23rd. This comes after more than three years since the decision to temporarily halt production of Skycellflu in February 2021. At that time, the company temporarily suspended domestic supply by converting the existing Skycellflu production line to focus on producing the COVID-19 vaccine 'Skycovione.' Accordingly, from next month, Skycellflu vaccinations will be available at domestic hospitals and clinics.

Starting shipment on this day, the amount of flu vaccine SK Bioscience will supply domestically until early next year will reach approximately 5 million doses. Although re-entering the influenza vaccine market after more than three years, the company explains that there is absolutely no problem with quality thanks to SK Bioscience's technological capabilities. Skycellflu, which was first introduced domestically in 2015, rose to the number one market share position within about four years of its launch. In the 2023-2024 national immunization program (NIP) bidding by the Korea Disease Control and Prevention Agency, it was allocated the largest quantity of 2.42 million doses, reaffirming its dominance in the flu vaccine market.

The World's First Cell-Cultured Quadrivalent Flu Vaccine... Less Likely to Mutate

SK Bioscience SkyCellFlu4 vaccine.
[Photo by SK Bioscience]

Skycellflu is the world's first quadrivalent flu vaccine produced by the cell-culture method to receive the World Health Organization (WHO) prequalification (PQ). The cell-culture method uses animal cells to culture the virus and produce the vaccine. This contrasts with most flu vaccines distributed domestically, which use the egg-based method, culturing the virus in fertilized eggs. Currently, SK Bioscience and the multinational pharmaceutical company Seqirus are the only ones to have successfully commercialized quadrivalent flu vaccines using the cell-culture method in the global market.

SK Bioscience explains that the cell-culture method allows for a shorter production period than the egg-based method, enabling rapid production and quick response to pandemics. Since fertilized eggs are not used in production, people with egg allergies can also receive the vaccine, and the use of antibiotics or preservatives is unnecessary due to the use of sterile bioreactors.

Another advantage is the lower possibility of vaccine mutation. In the egg-based method, the virus can mutate as it adapts to the fertilized eggs during culture and proliferation, but in the cell-culture method used for Skycellflu, the possibility of mutation is low, according to SK Bioscience. Influenza vaccines target different strains each year because the influenza virus undergoes slight mutations annually. The WHO announces the flu strains expected to circulate in the Northern Hemisphere each year, and vaccine manufacturers develop and produce vaccines based on those strains. The lower the possibility of mutation during this process, the more stable the vaccine's effectiveness.

Based on these advantages, overseas health authorities have recommended prioritizing cell-cultured flu vaccines. The UK's Joint Committee on Vaccination and Immunisation (JCVI) recently announced in its '2023-24 Seasonal Flu Vaccine Age Group Guide' that it prioritizes the cell-cultured quadrivalent flu vaccine for vaccination candidates aged 2 to 64.

Strict Quality Control Testing... Potential for Vaccine Market Expansion

Quality control (QC) work for the influenza vaccine 'Skycellflu' is underway at SK Bioscience L House in Andong-si, Gyeongbuk.
[Photo by SK Bioscience]

Some in the industry argue that the egg-based method, being a traditional vaccine manufacturing method, may offer greater stability. However, SK Bioscience conducts meticulous procedures to verify vaccine safety. In the QC laboratory I toured that day, researchers were conducting experiments to confirm safety. This process tests whether the vaccine contains sufficient antigen content and ensures vaccination safety from multiple angles. If the vaccine fails even once in any of the multiple tests, it cannot be shipped. Lee Ju-seop, team leader of the QC office at L House, explained, "After quality control testing, the vaccine undergoes re-evaluation at a national testing institution designated by the Ministry of Food and Drug Safety. The vaccine undergoes multiple tests from the bulk solution stage to the finished product." This multiple verification process guarantees the vaccine's safety.

With the onset of a full-fledged endemic (periodic infectious disease outbreak), demand for flu vaccines is expected to increase this year. This is due to an unusual 'summer flu' outbreak influenced by the complete lifting of mask mandates. According to the Korea Disease Control and Prevention Agency, from the 30th of last month to the 5th of this month, the number of suspected patients showing flu symptoms reached 14.1 per 1,000 people. This is 2.9 times higher than the epidemic threshold of 4.9 defined by the agency and three times higher than the peak recorded in 2016 during the same period.

The number of people eligible for free flu vaccination is also expected to increase. Since the end of last year, the Korea Disease Control and Prevention Agency has been conducting research projects to prioritize the introduction of national immunization for chronic disease patients and others. Since patients with chronic diseases such as hypertension and diabetes are at higher risk of progressing to severe influenza, free vaccination for these groups is anticipated. The industry expects the domestic vaccine market to gradually expand through this.

Expansion Planned for Andong L House Site... Songdo R&PD Center Also Progressing Smoothly

SK Bioscience Andong L House exterior.
Photo by Myunghwan Lee

The name of SK Bioscience's vaccine production base, Andong L House, carries the meaning of light. Located in the Gyeongbuk Bio-Industrial Complex and covering 20,000 pyeong (approximately 66,000 square meters), L House is equipped with facilities capable of producing up to 500 million doses of vaccines annually. In 2021, it undertook contract manufacturing of AstraZeneca's COVID-19 vaccine, making it the first domestically produced vaccine shipped from this site.

L House is preparing for expansion and additional facility improvements. SK Bioscience is in the process of acquiring an additional 30,000 pyeong (approximately 99,000 square meters) of land near L House to expand the factory. The facilities at L House will also be upgraded to meet EU-GMP (Good Manufacturing Practice) and US cGMP standards. Additionally, the global R&PD center planned for Songdo, Incheon, is under construction with a target completion in 2025. The Songdo R&PD center, which will also serve as the headquarters, will be responsible for the entire process from vaccine research and development to commercial production.

Lee Sang-gyun, Vice President and Plant Manager of SK Bioscience's L House, said, "Skycellflu is the culmination of advanced Korean vaccine technology. Through this market re-entry, we will expand the flu vaccine options for our citizens and reaffirm the competitiveness of our vaccines by expanding our presence in the global market."

Inspection and packaging of the influenza vaccine 'Skycellflu' are underway at SK Bioscience L House in Andong-si, Gyeongbuk.
[Photo by SK Bioscience]

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