AstraZeneca Prevails in Vaccine Injury Suit; 10th Circuit Reverses 2024 Ruling

For biotech and pharma executives, the ruling provides critical clarity on the scope of emergency liability shields. AstraZeneca's victory demonstrates that even explicit promises in trial consent forms may not override statutory immunity—though the court's remand highlights that defendants can still voluntarily assume liability. The case will influence risk management in future pandemic-era trial contracts.

A three-judge panel of the Tenth Circuit handed AstraZeneca a significant legal victory on July 23, 2026, when it reversed a lower court ruling and held that the Public Readiness and Emergency Preparedness Act (PREP Act) shields the pharmaceutical giant from a breach-of-contract lawsuit brought by a Utah woman who claims she was injured during the clinical trial of a COVID-19 vaccine. Brianne Dressen alleges she suffered debilitating symptoms after receiving the trial vaccine in 2020 and that AstraZeneca failed to honor its promise—set out in the informed consent form she signed—to cover the medical costs of any vaccine-related injuries. The case has traveled a winding procedural path, and the appellate decision, while largely favoring AstraZeneca, leaves the door slightly ajar for Dressen's claim by remanding for the district court to consider whether the company may have waived its statutory immunity through the language of that same consent form.

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AstraZeneca's victory demonstrates that even explicit promises in trial consent forms may not override statutory immunity—though the court's remand highlights that defendants can still voluntarily assume liability.

The PREP Act, enacted in 2005, was designed to encourage rapid development and deployment of medical countermeasures during public health emergencies by granting broad liability protections to manufacturers and distributors. During the COVID-19 pandemic, the Department of Health and Human Services issued a declaration that extended these protections to covered countermeasures, including the AstraZeneca trial vaccine. Dressen’s suit represents a test of just how far that immunity stretches. She argued that because she sued for breach of contract—not for personal injury in tort—the PREP Act should not apply. The district court initially agreed with her, denying AstraZeneca’s motion to dismiss in November 2024. But the Tenth Circuit saw the matter differently.

Writing for the panel, U.S. Circuit Judge Harris, a George W. Bush appointee, focused on the plain language of the statute: the PREP Act’s immunity provision covers “all claims for loss.” That phrase, the court reasoned, unambiguously encompasses claims grounded in contract as well as tort. By focusing on the type of harm claimed—loss—rather than the legal theory of recovery, the panel adopted an expansive reading that will reverberate far beyond this single lawsuit. However, the court did not hand AstraZeneca a total win. The opinion explicitly noted that a defendant can voluntarily assume liability, and it remanded for the district court to determine whether the informed consent form constituted a waiver of the Act’s immunity in this particular case. That form not only warned that the PREP Act might limit legal remedies but also contained an affirmative promise that the company would cover injury costs.

The ruling has immediate implications for the pharmaceutical and clinical research sectors. For vaccine and drug manufacturers, the decision reaffirms the strength of the PREP Act’s liability shield, reducing uncertainty and litigation risk during emergency product development. Companies conducting trials under public health emergency declarations can operate with greater confidence that even contractual promises in consent documents may not automatically override statutory immunity. At the same time, the remand on waiver injects a caution: if a company’s own documents contain an unambiguous, intentional relinquishment of immunity, courts may yet hold it to that bargain. This dual outcome will likely prompt legal departments at biotech and pharma firms to meticulously review and possibly revise informed consent language to avoid unintended waivers.