# EDGAR Filing Document

**Accession Number:** 0001084201
**File Stem:** 0001104659-23-024000
**Filing Date:** 2023-2
**Character Count:** 16448
**Document Hash:** d9536d4f9a84520c921fd461f8694996
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-23-024000.hdr.sgml**: 20230222

**ACCESSION NUMBER**: 0001104659-23-024000

**CONFORMED SUBMISSION TYPE**: 6-K

**PUBLIC DOCUMENT COUNT**: 3

**CONFORMED PERIOD OF REPORT**: 20230222

**FILED AS OF DATE**: 20230222

**DATE AS OF CHANGE**: 20230222

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** SINOVAC BIOTECH LTD
- **CENTRAL INDEX KEY:** 0001084201
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** B9
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 6-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-32371
- **FILM NUMBER:** 23650469

**BUSINESS ADDRESS:**
- **STREET 1:** NO. 15 ZHI TONG ROAD,
- **STREET 2:** ZHONGGUANCUN TECH PARK, CHANGPING DISTR.
- **CITY:** BEIJING
- **STATE:** F4
- **ZIP:** 102200
- **BUSINESS PHONE:** 86-10-82890088

**MAIL ADDRESS:**
- **STREET 1:** NO. 15 ZHI TONG ROAD,
- **STREET 2:** ZHONGGUANCUN TECH PARK, CHANGPING DISTR.
- **CITY:** BEIJING
- **STATE:** F4
- **ZIP:** 102200

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** NET FORCE SYSTEMS INC
- **DATE OF NAME CHANGE:** 19991110

**UNITED STATES<br> SECURITIES AND EXCHANGE COMMISSION**

**WASHINGTON, DC 20549**

**FORM 6-K**

**REPORT OF FOREIGN PRIVATE ISSUER**

**PURSUANT TO RULE 13a-16 OR 15d-16 UNDER** 

**THE SECURITIES EXCHANGE ACT OF 1934**

For the month of February 2023

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Commission File Number: 001-32371

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SINOVAC BIOTECH LTD.

No. 39 Shangdi Xi Road

Haidian District

Beijing 100085, People's Republic of China

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ⌧ Form 40-F ◻

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ◻

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ◻

CONTENTS

**Explanatory Note** 

On February 21, 2023, Sinovac Biotech Ltd. (the "Company") entered into a fourth amendment (the "Fourth Amendment") to the Amended and Restated Rights Agreement, dated as of February 22, 2019 (the "Amended and Restated Rights Agreement"), as amended by the Amendment to the Amended and Restated Rights Agreement dated as of February 19, 2020 (the "Amendment to Amended and Restated Rights Agreement"), by the Second Amendment to the Amended and Restated Rights Agreement dated as of February 21, 2021 (the "Second Amendment to Amended and Restated Rights Agreement), and by the Third Amendment to the Amended and Restated Rights Agreement dated as of February 21, 2022 (the "Third Amendment to Amended and Restated Rights Agreement), between the Company and Pacific Stock Transfer Company, as Rights Agent, to extend the expiration date of the rights contained therein from February 22, 2023 to February 22, 2024.

The foregoing summary of the Fourth Amendment is qualified in its entirety by reference to the full text of the Fourth Amendment, which is filed as Exhibit 4.1 hereto and is incorporated herein by reference. A copy of the Third Amendment to Amended and Restated Rights Agreement and a summary of its material terms were filed with the SEC on Form 6-K on February 22, 2022 (incorporated herein by reference by Exhibit 4.2). A copy of the Second Amendment to Amended and Restated Rights Agreement and a summary of its material terms were filed with the SEC on Form 6-K on February 22, 2021 (incorporated herein by reference by Exhibit 4.3). A copy of the Amendment to Amended and Restated Rights Agreement and a summary of its material terms were filed with the SEC on Form 6-K on February 21, 2020 (incorporated herein by reference by Exhibit 4.4). A copy of the Amended and Restated Rights Agreement and a summary of its material terms were filed with the Securities and Exchange Commission on Form 6-K on February 22, 2019 (incorporated herein by reference by Exhibit 4.5).

**Incorporation by Reference**

The summary of the Fourth Amendment above and Exhibit 4.1 attached hereto are hereby incorporated by reference into our registration statements on Form S-8 filed with the Securities and Exchange Commission on September 10, 2009 (File No. 333-161827) and Form S-8 filed with the Securities and Exchange Commission on September 4, 2013 (File No. 333-190980).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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| | |
|:---|:---|
| SINOVAC BIOTECH LTD. | SINOVAC BIOTECH LTD. |
| By: | /s/ Nan Wang |
| Name: | Nan Wang |
| Title: | Chief Financial Officer |

---

Date: February 22, 2023

**Exhibit Index**

[Exhibit 4.1](tm237534d1_ex4-1.htm) [Fourth Amendment to Amended and Restated Rights Agreement dated as of February 21, 2023 between Sinovac Biotech Ltd. and Pacific Stock Transfer Company, as Rights Agent](tm237534d1_ex4-1.htm)

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| | |
|:---|:---|
| [Exhibit 4.2](https://www.sec.gov/Archives/edgar/data/1084201/000110465922025433/tm227283d2_ex4-1.htm) | [Third Amendment to Amended and Restated Rights Agreement dated as of February 21, 2022 between Sinovac Biotech Ltd. and Pacific Stock Transfer Company, as Rights Agent (incorporated by reference to Exhibit 4.1 of the Report on Form 6-K dated February 22, 2022 of Sinovac Biotech Ltd.)](https://www.sec.gov/Archives/edgar/data/1084201/000110465922025433/tm227283d2_ex4-1.htm) |

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| | |
|:---|:---|
| [Exhibit 4.3](https://www.sec.gov/Archives/edgar/data/1084201/000110465921026215/tm217256d1_ex4-1.htm) | [Second Amendment to Amended and Restated Rights Agreement dated as of February 21, 2021 between Sinovac Biotech Ltd. and Pacific Stock Transfer Company, as Rights Agent (incorporated by reference to Exhibit 4.1 of the Report on Form 6-K dated February 22, 2021 of Sinovac Biotech Ltd.)](https://www.sec.gov/Archives/edgar/data/1084201/000110465921026215/tm217256d1_ex4-1.htm) |

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| | |
|:---|:---|
| [Exhibit 4.4](https://www.sec.gov/Archives/edgar/data/1084201/000110465920023900/tm209518d1_ex4-1.htm) | [Amendment to Amended and Restated Rights Agreement, dated as of February 19, 2020, between Sinovac Biotech Ltd. and Pacific Stock Transfer Company, as Rights Agent (incorporated by reference to Exhibit 4.1 of the Report on Form 6-K dated February 21, 2020 of Sinovac Biotech Ltd.)](https://www.sec.gov/Archives/edgar/data/1084201/000110465920023900/tm209518d1_ex4-1.htm) |

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| | |
|:---|:---|
| [Exhibit 4.5](https://www.sec.gov/Archives/edgar/data/1084201/000114420419009657/tv514004_ex99-6.htm) | [Amended and Restated Rights Agreement, dated as of February 22, 2019, between Sinovac Biotech Ltd. and Pacific Stock Transfer Company, as Rights Agent, which includes the Form of Certificate of Designations of Series C Junior Participating Preferred Shares as Exhibit A, the Form of Right Certificate as Exhibit B and the Summary of Rights to Purchase Preferred Shares as Exhibit C (incorporated by reference to Exhibit 99.6 of the Report on Form 6-K dated February 22, 2019 of Sinovac Biotech Ltd.)](https://www.sec.gov/Archives/edgar/data/1084201/000114420419009657/tv514004_ex99-6.htm) |

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[Exhibit 99.1](tm237534d1_ex99-1.htm) [Press Release](tm237534d1_ex99-1.htm)

## Exhibit 4.1

**Exhibit 4.1**

**SINOVAC BIOTECH LTD.**

and<br>**PACIFIC STOCK TRANSFER COMPANY**

as Rights Agent<br>**FOURTH AMENDMENT<br>TO<br>AMENDED AND RESTATED RIGHTS AGREEMENT**

Effective as of February 21, 2023

This Fourth Amendment (this "*Amendment*") to the Amended and Restated Rights Agreement (as defined below), is between Sinovac Biotech Ltd., an Antigua and Barbuda company (the "*Company*"), and Pacific Stock Transfer Company (the "*Rights Agent*").

WHEREAS, the Company and the Rights Agent have heretofore executed and entered into the Amended and Restated Rights Agreement dated as of February 22, 2019 (the "*Amended and Restated Rights Agreement*"), as amended by the Amendment to the Amended and Restated Rights Agreement, dated as of February 19, 2020, by the Second Amendment to the Amended and Restated Rights Agreement, dated as of February 21, 2021, and by the Third Amendment to the Amended and Restated Rights Agreement, dated as of February 21, 2022, between the Company and the Rights Agent;

WHEREAS, the Amended and Restated Rights Agreement, under its current terms, will expire on the close of business on February 22, 2023;

WHEREAS, pursuant to Section 26 of the Amended and Restated Rights Agreement, the Company and the Rights Agent may from time to time supplement or amend any provision of the Amended and Restated Rights Agreement in accordance with the provisions of Section 26 thereof;

WHEREAS, the Board of Directors of the Company has determined that it is in the best interests of the Company and the holders of the Rights to amend the Amended and Restated Rights Agreement as provided herein; and

WHEREAS, all acts and things necessary to make this Amendment a valid agreement according to its terms have been done and performed, and the execution and delivery of this Amendment by the Company and the Rights Agent have been in all respects authorized by the Company and the Rights Agent.

NOW, THEREFORE, in consideration of the foregoing and mutual agreements set forth herein, the Company and the Rights Agent agree as follows:

1. <u>Amendments</u>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.1 Section 7.1 of the Amended and Restated Rights Agreement is amended to replace the reference to "February 22, 2023" with
 "February 22, 2024".

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.2 All references to the date of "February 22, 2023" in Exhibit B (the Form of Right Certificate) and Exhibit C (the Summary
of Rights to Purchase Preferred Shares) to the Amended and Restated Rights Agreement shall hereby be changed to "February 22, 2024".

2. <u>Capitalized Terms</u>. Capitalized terms used herein but not defined shall have the meanings given to them in the Amended and Restated
Rights Agreement.

3. <u>Effect of Amendment</u>. Except as expressly amended hereby, the Amended and Restated Rights Agreement shall remain in full force
and effect in accordance with its terms.

4. <u>Benefits of Amendment</u>. Nothing in this Amendment shall be construed to give to any Person or corporation other than the Company,
the Rights Agent and the registered holders of the Right Certificates (and, prior to the Distribution Date, the Common Shares) any legal
or equitable right, remedy or claim under this Amendment; but this Amendment shall be for the sole and exclusive benefit of the Company,
the Rights Agent and the registered holders of the Right Certificates (and, prior to the Distribution Date, the Common Shares).

5. <u>Severability</u>. If any term, provision, covenant or restriction of this Amendment is held by a court of competent jurisdiction
or other authority to be invalid, void or unenforceable, the remainder of the terms, provisions, covenants and restrictions of this Amendment
shall remain in full force and effect and shall in no way be affected, impaired or invalidated. The parties hereto further agree to replace
such invalid, void or unenforceable provision of this Amendment with a valid, legal and enforceable provision that carries out the parties'
intentions to the greatest lawful extent under this Amendment.

6. <u>Governing Law</u>. This Amendment shall be deemed to be a contract made under the internal laws of the State of Delaware and for
all purposes shall be governed by and construed in accordance with the laws of such State applicable to contracts to be made and performed
entirely within such State.

7. <u>Counterparts</u>. This Amendment may be executed in any number of counterparts and each of such counterparts shall for all purposes
be deemed to be an original, and all such counterparts shall together constitute but one and the same instrument. A signature to this
Amendment transmitted electronically shall have the same authority, effect, and enforceability as an original signature.

8. <u>Descriptive Headings</u>. Descriptive headings of the several Sections of this Amendment are inserted for convenience only and
shall not control or affect the meaning or construction of any of the provisions hereof.

[*Signature page follows*.]

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to the Amended and Restated Rights Agreement to be duly executed, as of the day and year first above written.

---

| | |
|:---|:---|
| **SINOVAC BIOTECH LTD.** | **SINOVAC BIOTECH LTD.** |
| By: | /s/ YIN WEIDONG |
|  | Name: YIN WEIDONG |
|  | Title: Chairman, President & CEO |
| **PACIFIC STOCK TRANSFER COMPANY**, | **PACIFIC STOCK TRANSFER COMPANY**, |
| as Rights Agent | as Rights Agent |
| By: | /s/ JOSLYN G. CLAIBORNE |
|  | Name: JOSLYN G. CLAIBORNE |
|  | Title: Managing Director |

---

[Signature Page to the Fourth Amendment to Amended and Restated Rights Agreement]

## Exhibit 99.1

**Exhibit 99.1**

**Sinovac Amends Shareholder Rights Plan**

BEIJING, China, February 22, 2023 /Business Wire/ -- Sinovac Biotech Ltd. ("Sinovac" or the "Company") (NASDAQ: SVA), a leading provider of biopharmaceutical products in China, today announced that its board of directors has amended its shareholder rights plan. The amendment extends the expiration date of the plan from February 22, 2023 to February 22, 2024.

**About SINOVAC**

Sinovac Biotech Ltd. (SINOVAC) is a China-based biopharmaceutical company that focuses on the R&D, manufacturing, and commercialization of vaccines that protect against human infectious diseases.

SINOVAC's product portfolio includes vaccines against COVID-19, enterovirus 71 (EV71) infected hand-foot-mouth disease (HFMD), hepatitis A, varicella, influenza, poliomyelitis, pneumococcal disease, mumps, etc.

The COVID-19 vaccine, CoronaVac®, has been approved for use in more than 60 countries and regions worldwide. The hepatitis A vaccine, Healive®, passed WHO prequalification requirements in 2017. The EV71 vaccine, Inlive®, is an innovative vaccine under "Category 1 Preventative Biological Products" and commercialized in China in 2016. In 2022, SINOVAC's Sabin-strain inactivated polio vaccine (sIPV) and varicella vaccine were prequalified by the WHO.

SINOVAC was the first company to be granted approval for its H1N1 influenza vaccine Panflu.1®, which has supplied the Chinese government's vaccination campaign and stockpiling program. The Company is also the only supplier of the H5N1 pandemic influenza vaccine, Panflu®, to the Chinese government stockpiling program.

SINOVAC continually dedicates itself to new vaccine R&D, with more combination vaccine products in its pipeline, and constantly explores global market opportunities. SINOVAC plans to conduct more extensive and in-depth trade and cooperation with additional countries, and business and industry organizations.

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

**Safe Harbor Statement**

This press release may include certain statements that are not descriptions of historical facts, but are forward-looking statements. These statements are made under the "safe harbor" provisions of the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as "will," "expects," "anticipates," "future," "intends," "plans," "believes," "estimates" and similar statements. Forward-looking statements involve risks, uncertainties and other factors that could cause actual results to differ materially from those contained in any such statements. In particular, the outcome of any litigation is uncertain, and the Company cannot predict the potential results of the litigation it filed or filed against it by others. Additionally, the triggering of a shareholder rights plan is nearly unprecedented, and the Company cannot predict the impact on the Company or its stock price as a result of the trigger of the rights plan.

**Contacts**

**Sinovac Biotech Ltd.**

Helen Yang

Tel: +86-10-8279-9871 or

+86-10-5693-1897

Fax: +86-10-6296-6910

Email: ir@sinovac.com

**ICR Inc.**

Bill Zima

U.S.: 1-646-308-1707

Email: william.zima@icrinc.com