SVA Sinovac Biotech Ltd

(1) Representing 10,780,820 Common Shares of the Issuer held by SAIF Partners IV L.P. before taking into account the issuance of the Exchange Shares (as defined in the Issuer’s annual report on Form 20-F for the fiscal year ended December 31, 2022 (the “2022 Annual Report”)). SAIF Partners IV L.P. would hold 21,561,640 shares of the Issuer, after taking into account the issuance of the Exchange Shares.

(2) The percentage of 15.03% is calculated based on 71,724,902 Common Shares of the Issuer outstanding as of March 31, 2023 according to the 2022 Annual Report, before taking into account the issuance of the Exchange Shares. This percentage would be 18.89% if calculated based on 21,561,640 shares of the Issuer that SAIF Partners IV L.P. would hold and 114,133,056 shares (including 99,502,243 Common Shares and 14,630,813 Series B Preferred Shares) of the Issuer as of March 31, 2023, taking into account the issuance of the Exchange Shares, according to the 2022 Annual Report.

(1) Representing 10,780,820 Common Shares of the Issuer held by SAIF Partners IV L.P. before taking into account the issuance of the Exchange Shares. SAIF Partners IV L.P. would hold 21,561,640 shares of the Issuer, after taking into account the issuance of the Exchange Shares.

(2) The percentage of 15.03% is calculated based on 71,724,902 Common Shares of the Issuer outstanding as of March 31, 2023 according to the 2022 Annual Report, before taking into account the issuance of the Exchange Shares. This percentage would be 18.89% if calculated based on 21,561,640 shares of the Issuer that SAIF Partners IV L.P. would hold and 114,133,056 shares (including 99,502,243 common shares and 14,630,813 Series B Preferred Shares) of the Issuer as of March 31, 2023, taking into account the issuance of the Exchange Shares, according to the 2022 Annual Report.

(1) Representing 10,780,820 Common Shares of the Issuer held by SAIF Partners IV L.P. before taking into account the issuance of the Exchange Shares. SAIF Partners IV L.P. would hold 21,561,640 shares of the Issuer, after taking into account the issuance of the Exchange Shares.

(2) The percentage of 15.03% is calculated based on 71,724,902 Common Shares outstanding of the Issuer as of March 31, 2023 according to the 2022 Annual Report, before taking into account the issuance of the Exchange Shares. This percentage would be 18.89% if calculated based on 21,561,640 shares of the Issuer that SAIF Partners IV L.P. would hold and 114,133,056 shares (including 99,502,243 common shares and 14,630,813 Series B Preferred Shares) of the Issuer as of March 31, 2023, taking into account the issuance of the Exchange Shares, according to the 2022 Annual Report.

This Amendment No.9 to Schedule 13D is being filed on behalf of each of SAIF Partners IV L.P., SAIF IV GP, L.P., and SAIF IV GP Capital Ltd. (each, a “Reporting Person,” and collectively, the “Reporting Persons”), to amend the Schedule 13D relating to the common shares, par value $0.001 per share (the “Common Shares”), of Sinovac Biotech Ltd. (the “Issuer”), filed by the Reporting Persons on May 31, 2011, as amended by Amendment No.1 to Schedule 13D filed on August 23, 2011, Amendment No.2 to Schedule 13D filed on September 30, 2011, Amendment No.3 to Schedule 13D filed on November 29, 2011, Amendment No.4 to Schedule 13D filed on December 30, 2011, Amendment No.5 to Schedule 13D filed on February 2, 2016, Amendment No. 6 to Schedule 13D filed on June 26, 2017, Amendment No. 7 to Schedule 13D filed on December 12, 2022 and Amendment No. 8 to Schedule 13D filed on March 15, 2023 (the “Original Schedule 13D”). The information in each Item below amends the information disclosed under the corresponding Item of the Original Schedule 13D. Except as amended and supplemented in previous amendments and herein, the information set forth in the Original Schedule 13D remains unchanged. Capitalized terms used herein have meanings as assigned thereto in the Original Schedule 13D unless defined herein. The information set forth in response to each separate Item below shall be deemed to be a response to all Items where such information is relevant.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

Item 6 is hereby amended and supplemented as follows:

On May 25, 2023, the Seller and the Buyer entered into an amendment No.2 to the Investment Agreement (the “Amendment No.2”) to extend the period of the Buyer’s right of first refusal period (“ROFR Period”), during which the Buyer has a right to elect to purchase all of the shares of the Issuer that the Seller would sell to any person (other than any of its affiliate or an existing limited partner) at the same price and subject to the same material terms and conditions proposed by such person under the Investment Agreement (as amended), to August 25, 2023. As a result of this extension of the ROFR Period, the period during which the Buyer may exercise the Put Option is also extended in the following manner: (i) if the Buyer and the Seller enter into a share purchase agreement with respect to any shares of the Issuer by August 25, 2023, the Seller may exercise the Put Option prior to the closing of the sales under such share purchase agreement to sell the Put Option Shares to the Buyer; and (ii) if no such share purchase agreement is executed by August 25, 2023, the Seller may exercise the Put Option within 15 business days immediately after August 25, 2023 to sell the Put Option Shares to the Buyer.

References to each of the Investment Agreement and the Amendment No.2 in this Statement are qualified in their entirety by reference to the Investment Agreement and the Amendment No.2, which are attached hereto as exhibits or incorporated herein by reference as if set forth in their entirety herein.

Item 7. Material to Be Filed as Exhibits.

Item 7 of the Original Schedule 13D is hereby amended and restated as follows:

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: May 25, 2023