SINOVAC Receives Nasdaq Notification Regarding Late Filing of 2025 Annual Report

2026-05-30

BEIJING, China May 30, 2026 – Sinovac Biotech Ltd. (Nasdaq: SVA) ("SINOVAC" or the "Company"), a leading provider of biopharmaceutical products in China, today announced that it received a notification letter dated May 20, 2026 (the "Notification Letter"), from Nasdaq Listing Qualifications ("Nasdaq") stating that as of May 8, 2026, the Company had regained compliance with the periodic filing and interim financial requirements in Nasdaq Listing Rules 5250(c)(1) (the "Periodic Filing Rule") and 5250(c)(2), as required by the Panel's decision dated January 21, 2026. As previously disclosed on January 22, 2026, under the Panel's decision, SINOVAC was required to, on or before May 11, 2026, demonstrate compliance with such Nasdaq Listing Rules by completing filings of its annual report for the year ended December 31, 2024, on Form 20-F and an interim balance sheet and income statement as of the end of its second quarter of 2025 on Form 6-K. The Company timely completed such filings as required by the Panel's decision.

The Notification Letter also stated that the Company will be subject to a mandatory panel monitor (the "Panel Monitor") for a period of one year from the date of such letter. If, within that one-year monitoring period, the Nasdaq Listing Qualifications staff (the "Staff") finds the Company again out of compliance with the Periodic Filing Rule that was the subject of the exception, the Staff will issue a delist determination letter and the Company will have an opportunity to request a new hearing with the initial Panel or a newly convened Panel if the initial Panel is unavailable. The Company will have the opportunity to respond and present to the Panel as provided by Nasdaq Listing Rule 5815(d)(4)(C).

Subsequently, the Company received a delist determination letter (the "Staff Determination") from Nasdaq dated May 22, 2026, stating that because the Company has not timely filed its annual report on Form 20-F for the year ended December 31, 2025 (the "2025 Annual Report"), the Company no longer complies with the Periodic Filing Rule. Therefore, in accordance with the Panel Monitor, unless the Company timely requests a hearing before the Panel regarding the Staff Determination by May 29, 2026, the Company's securities would be subject to suspension and delisting.

Accordingly, the Company has today requested a hearing before the Panel. Such hearing request automatically stays the suspension of the Company's securities for a period of 22 calendar days from the date of the Staff Determination. The Company has also requested a further stay of any suspension action pending the completion of the hearing process.

Safe Harbor Statement

This announcement contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended, and as defined in the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as "may," "will," "expect," "anticipate," "aim," "estimate," "intend," "plan," "believe," "potential," "continue," "is/are likely to" or other similar expressions, including the Company's statements related to the timing and actions taken to regain compliance with Nasdaq listing rules. Such statements are based upon the Company's current expectations and current market and operating conditions and relate to events that involve known or unknown risks, uncertainties and other factors, including without limitation risks, uncertainties and factors related to the completion and filing of the 2025 Annual Report, and actions taken to regain compliance with the Nasdaq listing rules, all of which are difficult to predict and many of which are beyond the Company's control, which may cause the Company's actual results, performance or achievements to differ materially from those in the forward-looking statements. Further information regarding these and other risks, uncertainties or factors is included in the Company's filings with the U.S. Securities and Exchange Commission. The Company does not undertake any obligation to update any forward-looking statement as a result of new information, future events or otherwise, except as required under law.

Contacts

Sinovac Biotech Ltd.

Helen Yang

Tel: +86-10-8279 9779

Email: ir@sinovac.com

About SINOVAC

Sinovac Biotech Ltd. (SINOVAC) is a global biopharmaceutical company headquartered in China. Guided by its mission to “Supply Vaccines to Eliminate Human Diseases,” the Company is dedicated to the research, development, manufacturing and supply of vaccines and related biological products, providing vaccine products and related solutions for disease prevention and control worldwide.

SINOVAC has a diversified vaccine portfolio across multiple disease areas, including influenza, viral hepatitis, varicella, hand, foot and mouth disease (HFMD), poliomyelitis, rabies, tetanus, and pneumococcal disease. Three of SINOVAC's vaccines have been prequalified by the World Health Organization: the inactivated hepatitis A vaccine Healive®, the Sabin-strain inactivated poliomyelitis vaccine (sIPV), and the live attenuated varicella vaccine.

SINOVAC has extensive experience in vaccine research, development and commercialization for emerging infectious diseases and public health emergencies. The Company initiated vaccine R&D in response to major public health threats, including SARS, H5N1, H1N1, and COVID-19, and developed the world's first inactivated SARS vaccine (with Phase I clinical trials completed), China's first inactivated pandemic influenza vaccine against H5N1 (Panflu®), the world's first H1N1 influenza vaccine (Panflu.1®), and CoronaVac®, the world's most widely used inactivated COVID-19 vaccine. Beyond its marketed portfolio, SINOVAC continues to advance its R&D pipeline, spanning combination vaccines, recombinant protein vaccines, mRNA technologies, antibody-based products, and other next-generation technologies and product platforms, while expanding its capabilities in disease prevention and biopharmaceuticals.

With a long-standing commitment to innovation and global health, SINOVAC continues to deepen collaboration with research institutions, international organizations, and local partners while expanding its global presence. Through technological collaboration, localized production, and industrial partnerships, the Company aims to improve access to high-quality vaccines across regions, better address local disease prevention and healthcare needs, and strengthen preparedness for future public health challenges.

For more information, please see the Company's website at www.sinovac.com.