EU opens antitrust investigation into Sanofi over campaign disparaging rival flu vaccine

What the commission suspects

The European Commission opened a formal antitrust investigation into Sanofi on 26 June 2026, concerned that the company ran a misleading campaign to promote its enhanced flu vaccine Efluelda while disparaging the rival Fluad made by Australia's CSL Seqirus. The practices allegedly took place primarily in France and Germany, where the commission says Sanofi already holds a dominant position in the flu vaccine market.

Investigators suspect Sanofi presented Fluad as less effective and backed by weaker scientific evidence than Efluelda. According to Brussels, these claims contradicted conclusions from the European Centre for Disease Prevention and Control (ECDC) and the national immunisation technical advisory groups in both France and Germany. The commission also alleges that Sanofi misrepresented official vaccination recommendations and, in Germany, suggested that medical associations still had serious scientific objections to the rival vaccine, even though those reservations had been resolved.

“Scientific progress, impartial scientific assessments and trust in independent scientific authorities are fundamental to public health policies.”

“Flu vaccines help protect tens of thousands of Europeans every year. Today's decision to open a formal investigation shows the Commission's determination to address disparagement practices that can unduly harm competition and consumers' informed decision-making.”

Background and origin of the probe

The investigation follows unannounced inspections carried out at Sanofi offices in France and Germany in September 2025. At the time, Sanofi said it was confident of its compliance and would cooperate fully. The formal opening now gives Sanofi the opportunity to propose commitments to address the commission's concerns and potentially avoid fines.

Sanofi's response

Sanofi insists it has always acted in full compliance with all applicable laws, including competition rules. A company spokesperson told Agence France-Presse that the group "is convinced it has acted, and continues to act, in total conformity with all laws and regulations applicable, including competition law." The company noted that the opening of a formal procedure is a procedural step that does not prejudge the outcome of the investigation and said it takes the matter seriously and cooperates fully.

Potential consequences

If the allegations are substantiated, Sanofi could face sanctions for abuse of a dominant position under Article 102 of the Treaty on the Functioning of the European Union. While no specific penalty has been set out by the commission at this stage, EU antitrust rules allow fines of up to 10% of a company's global annual turnover. The case is a relatively rare example of the commission pursuing a pharmaceutical firm specifically over a disparagement campaign against a rival product, a line of action Brussels has signalled it is willing to pursue more actively.