Bylaw Amendment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C.  20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of report (Date of earliest event reported): December 9, 2022 PFIZER INC . (Exact name of registrant as specified in its charter) Delaware 1-3619 13-5315170 (State or other (Commission File (I.R.S. Employer jurisdiction of Number) Identification No.) incorporation)     235 East 42nd Street 10017 New York, New York (Zip Code) (Address of principal executive offices) Registrant’s telephone number, including area code: ( 212 ) 733-2323 Not Applicable (Former name or former address, if changed since last report) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communication pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2 (b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, $.05 par value PFE New York Stock Exchange 1.000% Notes due 2027 PFE27 New York Stock Exchange Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company     ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.      ☐ Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year. On December 9, 2022, the Board of Directors of Pfizer Inc. (the ”Company“) amended and restated the Company’s by-laws (the ”By-laws“). Among other things, the amendments require any shareholder submitting notice of a director nomination to: (i) inform the Company that such shareholder intends to solicit proxies in support of any director nominees in accordance with Rule 14a-19 under the Securities Exchange Act of 1934, as amended; and (ii) provide evidence that certain requirements of such rule have been satisfied. The amendments also incorporate certain other technical changes in light of the universal proxy rules adopted by the U.S. Securities and Exchange Commission. The foregoing description of the Company’s By-laws is qualified in all respects by reference to the text of the By-laws, a copy of which is filed as Exhibit 3.1 to this Current Report on Form 8-K and is incorporated herein by reference. Item 9.01 Financial Statements and Exhibits (d)  Exhibits Exhibit Number Exhibit Description 3.1 Pfizer Inc. By-laws, as amended on December 9, 2022 104 Cover Page Interactive Data File--the cover page XBRL tags are embedded within the Inline XBRL document. EXHIBIT INDEX Exhibit No. Description 3.1  Pfizer Inc. By-laws, as amended on December 9, 2022 104 Cover Page Interactive Data File--the cover page XBRL tags are embedded within the Inline XBRL document. 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 hereunto duly authorized.   PFIZER INC.               By: /s/ Margaret M. Madden     Margaret M. Madden     Senior Vice President and Corporate Secretary     Chief Governance Counsel       Dated: December 13, 2022