## Facts

- A minor claimant, through her parents, sought compensation under the National Childhood Vaccine Injury Act for Juvenile Rheumatoid Arthritis (Still’s disease) allegedly caused by childhood vaccinations including DTaP, MMR, and OPV.
- The alleged injury was not listed on the Vaccine Injury Table, so causation was not presumed and had to be proven as an off-table claim.
- The record included evidence of other possible triggering events around the onset period, including Mycoplasma infection, findings suggestive of sinus infection, tonsillitis, and a recent cold with diarrhea.
- The claimant relied primarily on expert testimony asserting that vaccination can trigger autoimmune disease and on the temporal relationship between vaccination and symptom onset.
- The Secretary relied on contrary medical evidence disputing that the timing supported vaccine causation and pointing to intercurrent infections as alternative causes.

## Issues

1. What showing must an off-table Vaccine Act claimant make to prove causation in fact by a preponderance of the evidence?
2. Whether the claimant proved that the vaccinations were a but-for cause and substantial factor in causing her Juvenile Rheumatoid Arthritis, given competing potential causes and disputed timing.

## Decision

- The en banc Federal Circuit reversed the Court of Federal Claims and reinstated the special master’s decision denying compensation.
- The court held that off-table claimants must prove causation in fact by a preponderance of the evidence, including but-for causation, and may use the three-part Althen framework as a method of proof.
- The court concluded that the special master permissibly found the claimant’s proof insufficient because temporal association and generalized theories did not establish that vaccination actually caused the condition in this case.
- The court emphasized the deferential review owed to special master factfinding and held the Court of Federal Claims improperly reweighed the evidence.

## Legal Principles

- For off-table Vaccine Act claims, the petitioner bears the burden to prove causation in fact by a preponderance of the evidence; no presumption of causation applies.
- Causation in fact requires proof that the vaccine was a but-for cause and a substantial factor in bringing about the injury.
- A petitioner may prove causation using a three-part showing: (1) a medical theory connecting the vaccine and injury, (2) a logical sequence of cause and effect showing the vaccine was the reason for the injury, and (3) a proximate temporal relationship; this framework does not replace the requirement to prove actual causation in the petitioner’s case.
- Temporal proximity alone is insufficient to prove causation in fact, particularly where the record contains other plausible causes that must be meaningfully addressed.
- In Vaccine Act cases, the Court of Federal Claims must review the special master’s fact findings deferentially and may not substitute its judgment where the findings reflect a rational reading of the record and are not arbitrary or capricious.

## Conclusion

The Federal Circuit held that an off-table Vaccine Act claimant must prove, by a preponderance of the evidence, that vaccination was the actual but-for cause of the injury, and it reinstated the special master’s denial where the claimant’s case rested largely on timing and generalized causation theories amid plausible alternative infectious triggers and disputed medically appropriate latency.


Pafford ex rel. Pafford v. Sec’y of Health & Hum. Servs., 451 F.3d 1352 (Fed. Cir. 2006) (en banc)