Evans Johnson v. HHS - HPV, immune thrombocytopenic purpura (ITP) (2017)

Lynn Johnson, as legal representative for her minor child E.J., filed a petition on February 7, 2014, seeking compensation under the National Vaccine Injury Compensation Program. The petition alleged that the human papillomavirus (HPV) vaccine administered on July 15, 2011, caused E.J. to develop immune thrombocytopenic purpura (ITP).

The case caption was later amended to identify Evans Johnson as the Petitioner after she reached adulthood. Petitioner's ITP was discovered incidentally on August 24, 2011, approximately 40 days after vaccination, when her platelet count was found to be low.

The public decision does not describe any symptoms experienced by the Petitioner related to ITP. Her condition was characterized as mild and chronic.

An entitlement hearing was held, and the Special Master, Brian H. Corcoran, issued a decision on January 6, 2017, denying the petition.

The resolution of the claim turned on whether the Petitioner's ITP began after she received the HPV vaccine. Petitioner's expert, Dr.

Paula Goodman Fraenkel, a hematologist and oncologist, opined that the HPV vaccine caused Petitioner's ITP, proposing molecular mimicry as the mechanism. She cited case studies and argued that ITP presentations are heterogeneous, not always acute, and that the timing of discovery (40 days post-vaccination) was within a medically acceptable timeframe.

However, Dr. Fraenkel admitted that the exact onset of Petitioner's ITP could not be determined from the record and that it could have begun before the vaccination.

Respondent's expert, Dr. Joan Cox Gill, a pediatric hematologist, testified that Petitioner's ITP was primary and chronic, not vaccine-related.

She argued that vaccine-associated ITP is typically acute and that the Petitioner's presentation was consistent with chronic ITP, which is less likely to be vaccine-related. Dr.

Gill also cited epidemiologic studies suggesting no causal link between the HPV vaccine and ITP. Both experts agreed that a 42-day timeframe post-vaccination would be reasonable for onset if the vaccine caused ITP.

Special Master Corcoran found that Petitioner failed to establish by a preponderance of the evidence that the onset of her ITP occurred after the vaccination, a critical element for an off-Table claim. While the Petitioner proposed a plausible theory of causation and demonstrated that ITP can be vaccine-associated, the inability to pinpoint post-vaccination onset was fatal to the claim.

The Special Master noted that Petitioner successfully established the first Althen prong (medical theory of causation) and argued for the second (logical sequence of cause and effect), but failed on the third (proximate temporal relationship) due to the lack of evidence for post-vaccination onset. The petition was denied.