Effective January 16, 2024 (the ?Transition Date?), the Board of Directors (the ?Board?) of HilleVax, Inc. (the ?Company?) appointed Sean McLoughlin to serve as the Company?s Chief Operating Officer, replacing Aditya Kohli. On the Transition Date, in connection with Mr. McLoughlin?s appointment, Dr. Kohli resigned as Chief Operating Officer and will continue his employment with the Company in an executive capacity. Effective February 19, 2024, Dr. Kohli will succeed David Socks as the Company?s Chief Business Officer; Mr. Socks?

employment with the Company will terminate and he will continue as a consultant to the Company as of such date. Mr. McLoughlin, age 52, previously held a number of roles of increasing responsibility at GlaxoSmithKline from May 1998 to January 2024. Most recently, he served as VP Global Commercial Lead ?

RSV from February 2021 to January 2024. Prior to that, he served as the New Product Strategy Lead of the Vaccines Business Unit from June 2019 to February 2021. Mr. McLoughlin holds a B.Sc.

in Accounting from Queen?s University of Belfast, Ireland, an M.B.A. from St. Joseph?s University, and a Certificate of Professional Development from The Wharton School Artesty Institute of Executive Education. Mr. McLoughlin has three decades of commercial and operational experience in vaccines, most recently as the Global Vaccine Commercialization Lead, RSV at GSK.

In this capacity, he was responsible for the successful commercial launch of GSK?s RSV product AREXVY. Prior to that Mr. McLoughlin held the position of New Product Strategy Lead, Vaccines Business Unit at GSK. He previously served as GSK?s U.S. Launch Lead, Shingrix.

Mr. McLoughlin was at GSK for over 25 years, during which he held various leadership positions of increasing responsibility.