Health Law Daily Wrap Up, COVID-19—10th Cir.: PREP Act immunity shields AstraZeneca from vaccine trial injuries, waiver of immunity remains a question, (Jul 30, 2026)

By Justin Marcus Smith, J.D.

In disagreement with the district court, the Tenth Circuit determined that the PREP Act shielded AstraZeneca from breach-of-contract claims; however, the company still faces litigation regarding potential waiver of the immunity.

The Public Readiness and Emergency Preparedness Act (PREP Act) immunized AstraZeneca entities against “any” claims in connection with a COVID-19 vaccine trial, including breach of contract claims, held the U.S. Court of Appeals for the Tenth Circuit. While reversing a district court's finding that an injured vaccine trial participant's breach of contract claim was not shielded by the PREP Act, the tenth circuit remanded the case for the district court to consider whether AstraZeneca waived its immunity in the informed consent form (Dressen v. AstraZeneca AB, No. 24-4114 (10th Cir. Jul. 23, 2026)).

Background. A participant in an AstraZeneca 2020 COVID-19 vaccine clinical trial alleged she suffered numerous, constant, and debilitating neuropathy symptoms as a result of the vaccination and that she was ultimately diagnosed with post-vaccine neuropathy dysautonomia and chronic inflammatory demyelinating polyneuropathy. She said she remained disabled after more than three years without enough reimbursement for her suffering, albeit the parties may have been in reimbursement discussions until 2022.

In 2024, the participant sued AstraZeneca AB (Sweden), AstraZeneca Pharmaceuticals LP (Delaware) (collectively, AstraZeneca), and Velocity Clinical Research, Inc. (Velocity). Velocity ran the clinical trial on behalf of AstraZeneca. The participant asserted claims for breach of contract and breach of the duty of good faith and fair dealing, but she voluntarily dismissed her claims against Velocity.

At the dismissal stage, evidence show the participant had signed an informed consent form (ICF) prior to the trial, which described her rights and responsibilities as a trial participant and disclosed possible side effects of the vaccine. The ICF also provided that a “study doctor” would provide medical treatment or refer to treatment in the event of illness or injury during the study, and that AstraZeneca had an insurance policy that would pay the reasonable cost of treatment for research injuries. The ICF defined research injuries as injuries caused by the vaccine, tests, or procedures, but excluded injuries caused by a patient’s usual medical care. The ICF further disclosed that federal law may limit the right to sue for vaccine-related injuries.

AstraZeneca moved for dismissal on the basis that the PREP Act, which limits the liability of certain covered entities during public health emergencies, barred the participant’s claims. However, the federal district court in Salt Lake City, Utah, denied dismissal on the basis that the PREP Act, despite its seemingly broad scope, only shields claims for tortious conduct and does not immunize contract breaches (see Lawsuit against AstraZeneca over injuries from a Covid-19 vaccine clinical trial can proceed, Nov. 6, 2024).

On AstraZeneca’s appeal, the Tenth Circuit, exercising jurisdiction under the collateral-order doctrine, reversed the district court's order, but remanded for the district court to consider whether AstraZeneca waived its immunity in the ICF.

Jurisdiction. Though jurisdiction was not challenged, the court reasoned it had jurisdiction over the appeal of the district court's non-final order by way of the collateral order doctrine, which allows for immediate appeal of orders which have "practical" finality. To be appealable under the doctrine, these orders must “(1) conclusively determine the disputed question, (2) resolve an important issue completely separate from the merits of the action, and (3) be effectively unreviewable on appeal from a final judgment.”

In finding the first two requirements satisfied, the court noted that the district conclusively held the PREP Act did not immunize AstraZeneca from the breach of contract claims because the statute did not cover them, and that the immunity question was important and independent of the merits of the claims for relief. Regarding the third requirement, the court found that the benefit of PREP Act immunity would be effectively lost if a party faces the burden of litigation from an error about such immunity.

Prep Act. The Public Readiness and Emergency Preparedness Act (PREP Act), which limits the liability of certain covered entities during public health emergencies, authorizes the HHS Secretary to limit a covered entity’s legal liability for losses relating to the administration of medical countermeasures such as vaccines during a public health emergency. 42 U.S.C. § 247d-6d(a)(1).

Under the Act, once the Secretary makes such a declaration, “a covered person shall be immune from suit and liability under Federal and State law with respect to all claims for loss caused by, arising out of, relating to, or resulting from the administration to or the use by an individual of a covered countermeasure." However, claims for loss must be causally related to the specified set of immunized activities.

Immunity. Rejecting the district court's findings to the contrary, the Tenth Circuit held the PREP Act's immunity includes breach of contract damages.

The court found that the PREP Act immunity provision said nothing about shielding covered persons from specific causes of action. Instead, it protected against particular claims for loss. The court held this would include breach of contract claims insofar as the statutory definition of loss, which included illness and disability, appeared to encompass many of the damages the participant sought. The participant did not argue the listed losses would only be recoverable in tort. The court concluded here that the very premise of the participant’s argument, that enumerated losses were recoverable only through tort claims, contradicted her own complaint which prayed for economic damages like past and future medical expenses foreseeably suffered.

The court also noted the PREP Act loss definition included business-interruption loss which may support recovery where there is no claim of any tortious action. The loss definition was sufficiently broad to say it encompassed any type of loss, which did not contradict congressional purpose, as Congress knew how to exclude contract claims if it so wished.

As for the remedial scheme, the participant argued that contract damages were not compensable under the Countermeasures Injury Compensation Program (CICP), whereas Congress would have included breach of contract remedies if it had meant to immunize breach of contract claims. The court questioned whether CICP would not compensate contract claim damages, but the argument was also unpersuasive to the extent the participant did not explain why Congress necessarily wanted CICP to address all claims shielded by the immunity clause. CICP only compensates for serious physical injury or death. By the participant’s logic, there would be no immunity for less significant claims.

As for the absurdity canon, the court disagreed that it would be absurd for the PREP Act immunity provision to encompass contract claims. Immunity pertinent to public health emergency was the statute’s purpose. The court footnoted that the participant relied on the least reliable form of legislative history: selective, non-definitive statements.

Without the broadest possible immunity, rapid vaccine development would have been unlikely. The court said it was difficult to see a reason to exempt contract claims, especially given that medical-malpractice claims were often asserted as contract breach claims in the past. The participant claimed there was something special about contract claims, that immunity “would erode public trust, disincentivize ethical conduct, and create lawless economic zones” pertinent to covered countermeasures such that people would choose to avoid dealing with manufacturers. The court did not find these assertions persuasive. The grant of immunity might be bad policy, but it was congressional policy, and the participant did not show absurdity to the point that the policy was so bizarre to be unthinkable and unintended.

The constitutional avoidance doctrine was inapplicable because PREP Act language immunizing “all claims for loss” and congressional intent was clear. Moreover, the court’s construction of the PREP Act did not raise a substantial Taking Clause question. Private contractual provisions could not defeat congressional power to regulate here where the government took nothing for its own use. After all, statutory limits on liability are commonplace. It would be “peculiar” to find them invalid takings of private property rights when they are rarely, if ever, held to be deprivation of property under the Due Process Clause of the Fifth Amendment.

Causation. Next, the court distinguished that even though PREP Act immunity extends to contract breach claims, it does not encompass all contract claims against covered persons. There is a causation requirement encompassing “caused by,” “arising out of,” “relating to,” or “resulting from.” This suggested Congress meant the causation requirement to be comprehensive. In that light, the court found it safe to say that application of the traditional but-for causation standard would suffice. The participant did not argue a foreseeability requirement and appeared to accept but-for causation.

The court rejected the participant's insistence that immunity did not apply because AstraZeneca's refusal to keep its alleged promise to cover injury costs was the "real" but-for cause of her damages, not the administration of the vaccine. Finding that this approach "misconceives the meaning of but-for cause," the court explained that, while AstraZeneca’s breach of promise could be a but-for cause of the alleged damages, that does not undermine the proposition that administration of the vaccine was also a but-for cause and she would have no claim against the company absent the injuries from the vaccine.

Last, the court found that the participant's reliance on the district court statement that the PREP Act did not bar legal injury because the research injury was not a sufficient condition for her claim, was misconceived. While true that research injury, alone, was not sufficient to state a breach of contract claim, the breach of promise was not in itself enough to state the claim without the injection injury. The issue in a but-for cause analysis is not whether an action or event was a sufficient condition, but whether it was a necessary condition. Here, the vaccine—a necessary condition—was the but-for cause.

Potential waiver. The Tenth Circuit remanded the case to the district court to determine whether PREP Act immunity can be waived, and if so, whether it was waived in this case.

The case is No. 24-4114.

Judge: Hartz, H.

Companies: AstraZeneca AB

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