Exhibit 5.1

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VectivBio Holding AG Aeschenvorstadt 36 4051 Basel Switzerland | | | | Homburger AG Prime Tower Hardstrasse 201 CH-8005 Zurich homburger.ch T +41 43 222 10 00 |
Zurich, January 27, 2023
VectivBio Holding AG – Registration Statement on Form S-8
Ladies and Gentlemen:
We, Homburger AG, have acted as special Swiss counsel to VectivBio Holding AG, a stock corporation incorporated under the laws of Switzerland (the Company), in connection with the filing of a registration statement on Form S-8 (the Registration Statement), to be filed with the United States Securities and Exchange Commission (the SEC) on the date hereof for the purpose of registering under the United States Securities Act of 1933, as amended (the Securities Act), an additional 6,760,000 ordinary shares of the Company, each with a nominal value of CHF 0.05 (the Ordinary Shares), that may be issued and/or delivered pursuant to the Amended 2021 EIP (as defined below). As such counsel, we have been requested to give our opinion as to certain legal matters of Swiss law.
Capitalized terms used but not defined herein have the meaning ascribed to them in the Documents (as defined below).
This opinion is confined to and given on the basis of the laws of Switzerland in force at the date hereof. Such laws and the interpretation thereof are subject to change. This opinion is also confined to the matters stated herein and is not to be read as extending, by implication or otherwise, to any document referred to in any of the Documents (other than as listed below) or any other matter.
