Case Model: Casey
Casey v. Secretary of Health and Human Services,
Office of Special Masters, No. 97-612V
Filed: Dec. 12, 2005
- Varicella vaccine
- Autoimmune reaction affecting the central and peripheral nervous systems
- Entitled to compensation
Petitioner Shannon E. Casey alleged that the varicella vaccination that she received on June 9, 1995 caused her encephalomyeloradiculoneurapathy, an autoimmune reaction affecting her central and peripheral nervous systems.
Special Master Sweeney found that the petitioner demonstrated that the vaccination did in fact cause the petitioner’s encephalomyeloneuritis, and thus she was entitled to compensation.
The petitioner’s evidence satisfied all three prongs of the Althen test of causation in fact.
The reasoning of the Special Master exhibits the following logical features:
- Under the first prong of Althen, the petitioner offered alternative causal chains, which may have operated in combination: a direct viral infection and an immune-mediated inflammatory response;
- Under the first prong of Althen, the petitioner successfully argued that the varicella vaccine can cause a direct viral infection (or an immune-mediated inflammatory response) in part because the natural varicella infection can do so, and because the varicella vaccine contains a live but attenuated varicella virus; and
- Under the second prong of Althen, the petitioner successfully argued specific causation in part on the basis of cerebellitis’s being a distinctive condition particularly associated with a natural varicella infection.