-- Indicative Announcement on Pricing for Shareholders' Inquiry-based Transfer

Securities code: 688136 Securities abbreviation: Sinovac Pharmaceutical Announcement number: 2025-076

Sinovac Biopharmaceutical Co., Ltd.

Indicative Announcement on Shareholder Inquiry and Transfer Pricing Situation

The shareholder Shenzhen Keyi Pharmaceutical Holdings Co., Ltd. (hereinafter referred to as the "transferor") guarantees that the information provided to Sinovac Biopharmaceutical Co., Ltd. (hereinafter referred to as the "Company") does not contain any false records, misleading statements or major omissions, and assumes legal responsibility for its authenticity, accuracy and completeness in accordance with the law. The company and all members of the board of directors guarantee that the content of the announcement is consistent with the information provided by the information disclosure obligor.

Important content reminder:

 According to the inquiry and purchase situation on September 15, 2025, the initially determined transfer price for this inquiry is 30.88 yuan/share.

 The transferred shares transferred by the transferee through price inquiry shall not be transferred within 6 months after the transfer.

1. Preliminary pricing for this inquiry and transfer

(1) After inquiring from institutional investors, the transfer price was initially determined to be 30.88 yuan/share.

(2) The number of institutional investors participating in this inquiry, transfer, quotation and subscription is 21, covering fund management companies, securities companies, qualified foreign institutional investors, private equity fund managers and other professional institutional investors. The total number of effective subscription shares of institutional investors participating in this inquiry, transfer, quotation and subscription is 10,190,000 shares, and the corresponding effective subscription multiple is 1.01 times.

(3) The shares to be transferred in this inquiry transfer have been fully subscribed. The transferees are initially determined to be 21 institutional investors, and the total number of shares to be transferred is 10,062,800 shares.

2. Risk warning

(1) The transferee and number of shares transferred in this inquiry are only preliminary results, and there are still risks such as judicial freezing and deduction of the shares to be transferred. The final result of the inquiry transfer shall be subject to the final processing result of the Shanghai Branch of China Securities Depository and Clearing Co., Ltd.

(2) This inquiry transfer does not involve changes in the company’s control rights and will not affect the company’s governance structure and ongoing operations.

Announcement is hereby made.

Board of Directors of Sinovac Biopharmaceutical Co., Ltd.

September 16, 2025