Exhibit 31.3

CERTIFICATIONS UNDER SECTION 302

I, Stephen S. Yoder, certify that:

1. I have reviewed Amendment No. 1 to the Annual Report on Form 10-K for the fiscal year ended December 31, 2023 of Pieris Pharmaceuticals, Inc.; and

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

Dated: April 29, 2024