SINOVAC Board of Directors Alerts Shareholders to Advantech/Prime Success’ New Lawsuit, Which Threatens to Prevent Payment of US$55.00 Special Dividend to All Valid Shareholders

The Board of Directors of SINOVAC Biotech Ltd. (NASDAQ: SVA) (“SINOVAC” or the “Company”), a leading provider of biopharmaceutical products in China, today disclosed that on June 12, 2025, Advantech/Prime Success filed a Petition for Emergency Injunctive Relief against SINOVAC, et al., naming as relief parties Cede & Co., The Depository Trust Company, and Equiniti (the dividend paying agent retained by the SINOVAC Board), which may prevent the SINOVAC Board from paying the US$55.00 special dividend as scheduled on or about July 9, 2025.

We learned that Vivo Capital’s counsel informed the paying agent that Vivo would challenge the dividend and asked the paying agent to withdraw from facilitating the distribution of the US$55.00 dividend declared by the SINOVAC Board to all valid shareholders.

The SINOVAC Board has an obligation to answer this Petition on behalf of all SINOVAC common shareholders to stand up to the egregious actions of Prime Success. We expect to file our Opposition Brief today at 5:00 p.m. Atlantic Standard Time, followed by a hearing on Wednesday, June 18.

We continue to be shocked by the self-serving, unnecessary actions by Advantech and Vivo Capital (together known as the “Dissenting Investor Group”) against SINOVAC, threatening the rightful dividend payment to all valid SINOVAC common shareholders. These incomprehensible actions are unacceptable to the SINOVAC Board because:

• The Dissenting Investor Group has already pocketed more than US$1.1 billion in dividends from SINOVAC’s operating subsidiary, while all SINOVAC’s valid shareholders received nothing.
• An amount equal to the aggregate amount of cash that would be payable under the US$55.00 per common share special dividend in respect of the 2018 PIPE shares has been set aside by the SINOVAC Board in an escrow account managed by an independent third party pending final resolution of the legal proceedings, which the Dissenting Investor Group initiated. Thus, there is no risk whatsoever that the Dissenting Investor Group’s allocations of the dividend will not be paid if the courts ultimately decide in their favor regarding the PIPE shares.

These new actions by the Dissenting Investor Group go against their assertions of their support of the US$55.00 dividend payment in their letters to shareholders and raises the question – how can you trust anything they say in their letters or press releases?