Valneva Shares Under Pressure Amid U.S. Legal Probe

Valneva shares fall 42% as a U.S. investigation into Lyme vaccine data overshadows positive chikungunya vaccine rollout and 2026 financial guidance.

Valneva’s stock is facing significant headwinds from a newly launched U.S. investigation, overshadowing positive operational updates presented by the company at the recent World Vaccine Congress. This clash of advancing clinical programs and mounting legal uncertainty has contributed to a steep monthly decline in the biotech firm's share price.

Shareholder Investigation Centers on Lyme Disease Vaccine Data

The source of the legal pressure is an inquiry initiated by the U.S. law firm Pomerantz LLP on behalf of shareholders. The probe focuses on the late March release of Phase 3 trial results for Valneva’s Lyme disease vaccine candidate, VLA15. While the data indicated an efficacy rate of approximately 73 percent, the study failed to meet its primary statistical endpoint due to an insufficient number of cases. Attorneys are now examining potential claims related to alleged unlawful business practices. The market’s reaction has been severe: over a 30-day period, the stock has plummeted by almost 42 percent, closing at €2.75 on Friday.

Operational Highlights and Financial Framework

Separate from these legal challenges, company management highlighted strong commercial progress for its approved chikungunya vaccine, IXCHIQ. In Washington, Valneva pointed to over 12,000 vaccinations already administered in Brazil. The successful rollout of this product is critical for the company, as it needs to offset revenue that will be lost when third-party manufacturing contracts expire.

Financially, Valneva reaffirmed its total revenue guidance for 2026, projecting it to fall between €155 million and €170 million. The company reported a net loss of €115.2 million for 2025, driven by substantial ongoing investments in research and development. Management stated that with liquidity reserves of around €110 million, its operations are secured for the foreseeable future.

Upcoming Catalysts on the Calendar

The pipeline’s progress will be measured against several imminent milestones:

• May 7, 2026: Release of first-quarter financial results and detailed updates on the commercial development of IXCHIQ.
• Mid-2026: Publication of Phase 2 data for the Shigella vaccine candidate, S4V2.

In the near term, the stock’s trajectory is likely to be influenced by developments in the U.S. investigation. Operationally, the forthcoming Shigella vaccine data represents the next major catalyst, with positive results potentially triggering a reassessment of Valneva’s entire development portfolio.