Zamora v. Secretary of Health and Human Services
21-1414V
Fed. Cl.Apr 14, 2025Background
- Isabel Zamora alleged that a 2019 influenza vaccination caused her to develop chronic fatigue syndrome (CFS).
- Zamora relied on expert testimony from a neurologist; the government relied on a rheumatologist.
- Prior to vaccination, Zamora had some controlled health conditions and had previously received flu vaccines.
- Both parties’ experts agreed Zamora suffers from CFS, but disagreed on the timing and causation.
- The court reviewed the evidentiary record, including medical literature, expert reports, and the procedural history of the vaccine claim.
- The standard of proof required Zamora to show, by preponderant evidence, that the flu vaccine can cause CFS as required by Althen v. Sec’y of Health & Human Servs.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Can the flu vaccine cause CFS? | Flu infection can cause CFS; theory of molecular mimicry should apply to vaccination; points to immunological literature and case reports. | No epidemiologic evidence supports flu vaccine causing CFS; points to large studies finding no increased risk after flu vaccination and challenges theory’s scientific basis. | Zamora did not prove flu vaccine can cause CFS; insufficient persuasive evidence on causation. |
| Reliability of Plaintiff’s Expert Evidence | Dr. Miglis’s theory of causation (molecular mimicry) applies, epidemiology studies are limited, case reports are informative. | Dr. Miglis did not adequately explain specifics; theory lacks empirical support; case reports not persuasive, epidemiology is against causation. | Court found Dr. Miglis’s theory vague and unsupported; no persuasive showing of causation. |
| Timing of onset of CFS (Althen Prong 3) | Symptoms began within medically plausible timeframe post-vaccination (weeks to months). | Onset was vague and not well-defined; Zamora continued working, casting doubt on timing; Dr. Staud claims onset predates vaccination. | Court found plaintiff’s evidence on timing was too vague; did not convincingly establish a medically appropriate interval. |
| Preponderance of Evidence Standard Met | Plaintiff’s evidence sufficient even if not medically certain. | Plaintiff did not meet preponderance standard; evidence and expert opinion lack detail, specificity, and support. | Court held Zamora did not meet preponderance of evidence required under Vaccine Act. |
Key Cases Cited
- Moberly v. Sec’y of Health & Hum. Servs., 592 F.3d 1315 (Fed. Cir. 2010) (articulates preponderance of the evidence standard in vaccine claims)
- Andreu v. Sec’y of Health & Hum. Servs., 569 F.3d 1367 (Fed. Cir. 2009) (clarifies proper evidentiary burden in vaccine cases is preponderance, not medical certainty)
- Bunting v. Sec’y of Health & Hum. Servs., 931 F.2d 867 (Fed. Cir. 1991) (preponderant evidence allows recovery even absent medical certainty)
- Althen v. Sec’y of Health & Hum. Servs., 418 F.3d 1274 (Fed. Cir. 2005) (sets forth three-prong causation test for non-table vaccine injuries)
- Lampe v. Sec’y of Health & Hum. Servs., 219 F.3d 1357 (Fed. Cir. 2000) (addresses burden of proof in vaccine cases)
- Hodges v. Sec’y of Health & Hum. Servs., 9 F.3d 958 (Fed. Cir. 1993) (distinction between medical certainty and preponderant evidence)
- Capizzano v. Sec’y of Health & Hum. Servs., 440 F.3d 1317 (Fed. Cir. 2006) (discusses logical sequence of cause and effect in vaccine injury claims)