GC Biopharma's Varicella Vaccine Strain 'MAV/06' Listed in WHO Position Paper

• Officially recognized by WHO as a standard varicella vaccine strain alongside Oka
• Interchangeability endorsed, enhancing global supply security

YONGIN, South Korea, Dec. 2, 2025 /PRNewswire/ -- GC Biopharma (006280.KS), a global biopharmaceutical company, today announced that its proprietary varicella vaccine strain MAV/06 has been included in the World Health Organization (WHO) Position Paper on varicella vaccination, published on November 21.

WHO Position Paper serves as the most authoritative global guidance for immunization policy, developed by the Strategic Advisory Group of Experts on Immunization (SAGE).

With this inclusion, BARYCELA Inj. — GC Biopharma's varicella vaccine based on the MAV/06 strain — has attained equivalent international recognition to Oka strain-based vaccines. The WHO also endorsed the interchangeability of MAV/06 and Oka strains, allowing BARYCELA Inj. to be vaccinated with existing varicella vaccines in two-dose immunization schedules. This positions BARYCELA Inj. as a validated alternative in the global varicella vaccine market.

The immunogenicity and safety of MAV/06 were confirmed in a Phase 3 clinical trial of BARYCELA Inj., published in a peer-reviewed journal. The study demonstrated strong immune responses and a favorable safety profile, supporting its use in national immunization programs.

The endorsement establishes a more resilient global supply framework by enabling substitution between strains, thereby minimizing the risk of supply shortage and improving vaccination continuity across markets.

GC Biopharma expects the WHO recognition to strengthen its position in global procurement platforms such as the Pan American Health Organization (PAHO), where BARYCELA Inj. has already been stably supplied for years.

"The inclusion of MAV/06 in the WHO Position Paper mark a significant milestone in strengthening global varicella vaccine supply," said Jaewoo Lee, Head of the Regulatory Science & Product Development at GC Biopharma. "With validated manufacturing capabilities and a strong track record of international supply, we're committed to supporting global immunization efforts with reliable access to high-quality vaccines."

The MAV/06 strain was developed in-house by GC Biopharma in 1993 and has been used in products such as Suduvax and BARYCELA Inj. for nearly 30 years, including supplies through PAHO to various markets.

About GC Biopharma

GC Biopharma (formerly known as Green Cross Corporation) is a biopharmaceutical company headquartered in Yong-in, South Korea. The company has over half a century of experience in the development and manufacturing of plasma derivatives and vaccines, and is expanding its global presence with successful US market entry of Alyglo^® (intravenous immunoglobulin G) in 2024. In line with its mission to meet the demands of future healthcare, GC Biopharma continues to drive innovation by leveraging its core R&D capabilities in engineering of proteins, mRNAs, and lipid nanoparticle (LNP) drug delivery platform to develop therapeutics for the field of rare disease as well as I&I (Immunology & Inflammation). To learn more about the company, visit https://www.gcbiopharma.com/eng/

This press release may contain biopharmaceuticals in forward-looking statements, which express the current beliefs and expectations of GC Biopharma's management. Such statements do not represent any guarantee by GC Biopharma or its management of future performance and involve known and unknown risks, uncertainties, and other factors. GC Biopharma undertakes no obligation to update or revise any forward-looking statement contained in this press release or any other forward-looking statements it may make, except as required by law or stock exchange rule.

GC Biopharma Contacts (Media)

Sohee Kim
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Yelin Jun
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Yoonjae Na
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SOURCE GC Biopharma