The Department of Health and Human Services, specifically the Office of Assistant Secretary for Preparedness and Response (BARDA), is seeking qualified contractors to support the development of vaccine medical countermeasures for pandemic influenza preparedness and response. The objective of this Sources Sought Notice (SSN) is to refine requirements and establish long-term partnerships with contractors capable of producing vaccines, antigens, and adjuvants necessary for pandemic preparedness and public health emergencies. This initiative is critical for enhancing the U.S. response to influenza viruses with pandemic potential and ensuring rapid regulatory decisions and manufacturing readiness. Interested parties must submit evidence of eligibility, capabilities statements, and requests to participate by email to Laura Saddison at Laura.Saddison@hhs.gov by 3:00 pm EST on December 19, 2025. This SSN/RFI is for information and planning purposes only and does not constitute a solicitation.