Exhibit 32.1

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350

AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report on Form 10-Q of Mosaic ImmunoEngineering, Inc., a Delaware corporation (the “Company”) for the quarter ended June 30, 2025, as filed with the Securities and Exchange Commission on August 19, 2025 (the “Report”), the undersigned officer of the Company does hereby certify, pursuant to Title 18 of the United States Code Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to his knowledge:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: August 19, 2025

/s/ Steven King

Steven King. President, Chief Executive Officer, Director

(Principal Executive Officer, Principal Financial Officer and Principal Accounting Officer)

A signed original of this written statement required by Section 906 has been provided to Mosaic ImmunoEngineering, Inc. and will be retained by Mosaic ImmunoEngineering, Inc. and furnished to the Securities and Exchange Commission or its staff upon request.

This Certification is being furnished pursuant to Rule 15(d) and shall not be deemed “filed” for purposes of Section 18 of the Exchange Act (15 U.S.C. 78r), or otherwise subject to the liability of that section. This Certification shall not be deemed to be incorporated by reference into any filing under the Securities Act or the Exchange Act, except to the extent that the Company specifically incorporates it by reference.

Mosaic ImmunoEngineering Inc. 10-Q