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# EC Opens Antitrust Probe into Sanofi's Flu Vaccine Marketing
- URL: https://www.fdaweb.com/ec-opens-antitrust-probe-into-sanofis-flu-vaccine-marketing/
- Published: 2026-06-26T12:00:00.000Z
- Updated: 2026-09-14T13:42:02.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5161387

The European Commission has opened a [formal antitrust investigation](https://ec.europa.eu/commission/presscorner/detail/en/ip%5F26%5F1454?ref=fdaweb.com) into whether Sanofi abused its dominant market position by allegedly conducting a misleading campaign against a rival influenza vaccine marketed by CSL Seqirus. The investigation centers on Sanofi's promotion of its enhanced influenza vaccine, Efluelda, which competes in Europe with CSL Seqirus' Fluad, both of which are recommended for older adults and other vulnerable patients.

According to the Commission, Sanofi may have sought to undermine Fluad through communications directed primarily at healthcare professionals in Germany and France, where regulators believe Sanofi holds a dominant position in the enhanced flu vaccine market.

The Commission said it is examining whether Sanofi made claims suggesting Fluad was supported by weaker clinical evidence than Efluelda, despite conclusions reached by European regulators and national immunization advisory groups. Investigators are also reviewing whether the company inaccurately characterized national vaccination recommendations and, in Germany, suggested that scientific concerns about Fluad remained unresolved despite official recommendations supporting its use.

If substantiated, the conduct could constitute an abuse of a dominant market position under Article 102 of the Treaty on the Functioning of the European Union, which prohibits anticompetitive practices by companies with significant market power.

The investigation follows unannounced inspections conducted at Sanofi facilities in September 2025.