SAIF Partners IV L.P. → SINOVAC BIOTECH LTD SVA

Item 4 is hereby amended and supplemented to add the following: On April 28, 2025, at the request of SAIF Partners IV L.P. ("SAIF"), Cede & Co., as nominee of The Depository Trust Company and the holder of record of the 10,780,820 shares of the Issuer beneficially owned by SAIF, submitted a requisition to the board of directors (the "Board") of the Issuer (the "Requisition"), to convene a special shareholders' meeting of the Issuer (the "Special Shareholders' Meeting") for the purposes of (i) removing each of David Guowei Wang, Pengfei Li, and Sven H. Borho from the Board as well as any other person or persons elected or appointed to the Board without shareholders' approval after February 8, 2025 and up to and including the date of the Special Shareholders' Meeting (other than any Nominee set forth below), effective immediately (the "Removal Proposal"), and (ii) electing each of Simon Anderson, Shan Fu, Shuge Jiao, Chiang Li, Yuk Lam Lo, Yumin Qiu, Yu Wang, Rui-Ping Xiao, Andrew Y Yan, and Weidong Yin (each a "Nominee" and collectively, the "Nominees") to the Board, effective immediately (the "Election Proposal"). The foregoing summary of the Requisition is not intended to be complete and is qualified in its entirety by reference to the full text of the Requisition letter, which is filed as Exhibit 1 hereto and is incorporated herein by reference. The Reporting Persons have also engaged in preliminary discussions with other shareholders of the Issuer regarding Cede & Co.'s submission of the Requisition. The Reporting Persons plan to continue communicating with the Issuer and with other shareholders regarding these and similar matters. Depending upon, among other things, the outcome of these communications, the financial condition, results of operations and prospects of the Issuer, conditions in the securities markets, general economic conditions and other factors that the Reporting Persons deem relevant, the Reporting Persons may take other steps seeking to bring about changes to the Board that it believes would increase shareholder value as well as pursue other plans or proposals that relate to or would result in any of the matters set forth in clauses (a)-(j) of Item 4 of Schedule 13D.