Shingles Vaccine Lawsuit Update: Settlement, Dismissals, Appeal

The shingles vaccine lawsuits against Merck, targeting its older live-virus vaccine Zostavax, have largely ended. A master settlement agreement was signed on June 25, 2025, covering remaining federal and New Jersey state cases, and the federal multidistrict litigation collapsed earlier after courts ruled that plaintiffs could not scientifically prove Zostavax, rather than the dormant chickenpox virus already in their bodies, caused their shingles. More than 1,189 federal cases were dismissed in December 2022, the Third Circuit upheld those dismissals in July 2024, and another 296 cases were thrown out in April 2026 for failing to meet post-settlement deadlines.

What Patients Said the Vaccine Did

Zostavax contained a live but weakened form of the varicella-zoster virus, the same virus responsible for chickenpox and shingles. Plaintiffs argued that Merck sold a vaccine that was unreasonably dangerous and failed to warn patients and doctors about its risks. The central claim was that the live virus in the vaccine could cause the very disease it was supposed to prevent.¹

Beyond shingles, patients blamed the vaccine for blindness and vision loss, hearing loss, Bell’s palsy, Guillain-Barré syndrome, autoimmune disorders, brain inflammation, chronic nerve pain, and in some cases death. The legal theories ran along familiar product liability lines: failure to warn, defective design, negligence, and negligent misrepresentation, with some individual plaintiffs adding breach of warranty and fraud claims.¹²

Merck’s main defense turned on causation. Almost every American adult over 30 already carries the wild-type varicella-zoster virus from a childhood chickenpox infection, and that latent virus can reactivate on its own at any time. Merck argued plaintiffs could not show their shingles came from the vaccine rather than their own dormant virus. The company also invoked the learned intermediary doctrine, which limits a drugmaker’s duty to warn to the prescribing physician rather than the patient.²

Why the Federal Cases Fell Apart

In August 2018 the federal cases were consolidated into In re: Zostavax (Zoster Vaccine Live) Products Liability Litigation, MDL No. 2848, in the Eastern District of Pennsylvania before Judge Harvey Bartle III. The MDL grew to roughly 2,800 plaintiffs and was split into two groups: Group A for claims that the vaccine caused shingles or related injuries, and Group B for autoimmune conditions and other illnesses.³⁴

The PCR Test Problem

To tell a vaccine-strain shingles outbreak apart from a natural reactivation of the wild-type virus, laboratories need a polymerase chain reaction (PCR) test of the rash fluid. Between 2018 and 2021, the court prepared five bellwether cases for trial. None made it to a jury. In each one, the judge excluded the plaintiffs’ causation expert and granted summary judgment to Merck, finding plaintiffs could not establish that the vaccine, rather than the wild-type virus, caused their condition.⁵⁴

The Lone Pine Order

After three years in which plaintiffs produced no medical literature or expert opinion explaining how to prove vaccine causation without a PCR test, Judge Bartle issued a Lone Pine order. It directed the 1,189 remaining Group A plaintiffs to produce PCR test results within 90 days. For most, the rashes had healed years earlier and no such test existed. When no plaintiff complied, Judge Bartle dismissed all 1,189 Group A cases with prejudice in December 2022.⁶⁴

The Third Circuit Appeal

Plaintiffs appealed, arguing the order required evidence that could not exist. On July 16, 2024, the U.S. Court of Appeals for the Third Circuit affirmed the dismissals in an unpublished opinion. The panel held that the order was grounded in “uncontradicted record evidence” that PCR testing was the only way to establish causation, and that plaintiffs had been given three years to propose any alternative method and never did. Keeping nearly 1,200 cases on the docket without a viable causation theory, the court said, would have been “pointless.” The court acknowledged plaintiffs had not acted in bad faith but found that continuing the cases was “severely prejudicial” to Merck.⁶⁷

The 2025 Master Settlement

On June 25, 2025, the parties executed a master settlement agreement in the federal MDL. The total dollar amount, the number of plaintiffs covered, and individual payout figures have not been publicly disclosed. Participating plaintiffs were required to sign releases or file stipulations of dismissal within 90 days. Plaintiffs who chose not to participate were given deadlines to produce medical records, pharmacy records, and expert reports or face dismissal.⁸

Many did not meet those deadlines. On April 8, 2026, Judge Bartle dismissed another 296 cases with prejudice for failure to prosecute.⁹

The New Jersey State Court Cases

A parallel track ran in New Jersey. On July 17, 2018, the state Supreme Court designated all Zostavax injury claims as multicounty litigation (MCL No. 629), centralizing them in Middlesex County before Judge James F. Hyland. Roughly 800 cases were consolidated at the outset.¹⁰¹¹

The state court did not impose the Lone Pine order or the PCR testing requirement that dismantled the federal Group A docket. New Jersey issued its own master settlement on the same June 25, 2025, date, with a 90-day participation window.⁸ As of March 2026, the MCL remains active. The court continues to issue case management orders, amended stay orders, and dismissals for cases that fail to comply with docket control.¹²

This Was Not a Class Action

Despite common references to a “Zostavax class action,” neither the federal MDL nor the New Jersey MCL was ever certified as one. Both consist of individual lawsuits grouped together only for pretrial management. Each plaintiff had to prove their own injuries and their own causation; there was no class representative and no classwide damages determination. That individual-causation requirement is precisely what sank the Group A cases, because each plaintiff needed PCR evidence tying their own illness to the vaccine.¹⁰

What the FDA’s Safety Data Showed

Between Zostavax’s 2006 approval and January 2015, the FDA’s Vaccine Adverse Event Reporting System (VAERS) received 23,092 reports linked to the vaccine. About 4%, or 972 reports, were classified as serious. The most commonly reported serious adverse event was herpes zoster itself, appearing in 29% of serious reports. Other commonly reported serious symptoms included pain, rash, fever, difficulty breathing, and headache.¹³

Laboratory confirmation of the vaccine strain causing infection was rare. Just six cases were confirmed through PCR testing during the surveillance period. Seventy-four deaths were reported, but a review attributed them primarily to heart disease, sepsis, and stroke, causes consistent with expected mortality in the vaccine’s elderly target population. The FDA concluded the post-marketing data “did not detect any new or unexpected safety signals” beyond what pre-licensure clinical trials had already shown.¹³

Merck stopped making Zostavax in June 2020, and the vaccine was officially discontinued in the United States on November 18, 2020, after Shingrix, a more effective non-live vaccine from GlaxoSmithKline, replaced it in CDC recommendations.¹⁴

1
ClassAction.com. Zostavax Lawsuits
2
GovInfo. Zostavax Product Liability Case, Eastern District of Pennsylvania
3
Courthouse News Service. In Re Zostavax MDL Court Filing
4
FDLI. In Re Zostavax Products Liability Litigation
5
Fierce Pharma. Merck Puts More Than 1,000 Zostavax Lawsuits to Bed
6
Washington Legal Foundation. Third Circuit Decision Upholds Lone Pine Order
7
Drug and Device Law Blog. Zostavax Lone Pine: The Appeal
8
New Jersey Courts. Zostavax Master Settlement Agreement CMO
9
HarrisMartin. Zostavax MDL Judge Dismisses 296 Cases for Failure to Prosecute
10
New Jersey Courts. Zostavax Case Information
11
Faegre Drinker on Products. New Jersey MCL Update: Three New Consolidated Litigations
12
New Jersey Courts. Zostavax Orders and Decisions
13
National Center for Biotechnology Information. Post-Marketing Safety Surveillance of Zoster Vaccine Live
14
CDC Archive. Zostavax Vaccination Information