A German appellate court has ordered the reopening of a damages lawsuit against BioNTech brought by a man who alleges his health problems are linked to two doses of the company’s Covid-19 vaccine, in a decision that could set a precedent for similar proceedings across Germany, according to German news outlet Apollo News.
The Higher Regional Court of Hamm (Oberlandesgericht Hamm), in western Germany, ruled on April 21, 2026 that the lower Regional Court of Arnsberg (Landgericht Arnsberg) must re-examine the case of a man who had sought information from BioNTech, suspecting that two vaccine doses might be linked to several health issues.
The plaintiff received his Covid-19 vaccinations in July 2021 and March 2022, after having already had a coronavirus infection. He subsequently alleged he suffered deep-vein thrombosis, dizziness, headaches and numbness in his feet, and is claiming €150,000 in damages plus information on potential risks of the product.
Comirnaty was developed by BioNTech together with US drugmaker Pfizer, but BioNTech holds the marketing authorisation in Germany and is therefore the sole defendant in this case.
In the first instance, the Arnsberg court heard the plaintiff but rejected the case without ordering expert medical evidence, ruling that he had not shown with sufficient probability a link between the vaccination and his ailments, Apollo News reported.
The Hamm court overruled that approach and ordered the proceedings reopened, citing procedural errors. To seek information from the manufacturer under section 84a of Germany’s Medicines Act (Arzneimittelgesetz), it is not necessary to prove highly probable causality at the outset. A plausible suspicion of vaccine-related harm is enough.
That reading follows the line set by the Federal Court of Justice (Bundesgerichtshof, BGH) in a ruling of March 9, 2026. The BGH established that plausibility does not require the vaccine to be the most probable cause of harm, and could exist even where more factors weigh against than in favour of such causality.
In this case, the Arnsberg judges had dismissed the possible link by citing the time elapsed between the first dose and the thrombosis diagnosis. According to medical documentation, the deep-vein thrombosis was diagnosed four months after the first vaccination, while the dizziness had appeared shortly before.
The Hamm court found the first-instance judges could not attribute those ailments to orthopaedic history without first hearing medical experts. In other words, the lower court could not close the case for lack of probability without proper evidentiary procedure.
The decision does not mean BioNTech has been found liable or that the court has acknowledged that the vaccine caused the alleged harm. It establishes that the plaintiff is entitled to have his case re-examined under a less restrictive evidentiary threshold for requesting information from the manufacturer.
The ruling could have consequences for other similar proceedings, Apollo News noted. If German courts settle on the view that a plausible suspicion is enough to compel disclosure, more claimants could gain access to internal data on risks, side effects and safety assessments of vaccines.
