I.H. v. HHS - DTaP, seizure disorder (2024)

On January 29, 2016, Paula Heilig, mother of I.H., filed a petition for compensation under the National Vaccine Injury Compensation Program on behalf of her minor daughter, I.H. The petition alleged that I.H. developed a seizure disorder as a result of the DTaP, hepatitis B, inactivated polio (IPV), haemophilus influenzae type b (Hib), rotavirus, and pneumococcal conjugate (PCV) vaccines she received on March 6, 2013.

The petition also alleged that the drug treatment for her seizure disorder caused neutropenia, but this aspect of the claim was not pursued. I.H. was born on September 7, 2012.

Prior to her vaccinations, she was generally healthy and developing normally. On March 6, 2013, at her six-month well-child visit, she received the aforementioned vaccines.

The following day, March 7, 2013, I.H. experienced a prolonged seizure lasting approximately 30 minutes. She was taken to the emergency room, where her temperature was recorded as 100.8-100.9 degrees Fahrenheit.

She also tested positive for respiratory syncytial virus (RSV), though there were no clear contemporaneous signs of active respiratory illness. Head CT imaging was normal, but an EEG showed generalized spike-and-wave activity indicative of generalized epilepsy.

I.H. was discharged with a diagnosis of febrile convulsions and acute bronchiolitis due to RSV. Over the following years, I.H. experienced recurrent seizures.

Medical records indicated a small, nonspecific abnormality in her left frontal lobe on MRI, and her EEGs showed generalized spike-and-wave activity. Her treating physicians noted a family history of febrile seizures in her father and paternal grandmother.

I.H. was diagnosed with neutropenia in June 2013, which was later deemed most likely autoimmune. Petitioner's theory of causation, as refined by her expert Dr.

Marcel Kinsbourne, was that the DTaP vaccine caused a fever, which triggered a prolonged febrile seizure in I.H., who had an underlying cortical dysplasia or susceptibility. This event, a "second hit," lowered her seizure threshold, leading to the development of epilepsy.

Dr. Kinsbourne opined that the DTaP vaccine, specifically its pertussis component, could cause fever and seizures, and that the onset of I.H.'s seizure approximately 18 hours after vaccination was medically appropriate.

He cited medical literature suggesting that cortical dysplasia alone may not cause epilepsy and that a "second hit" is often required. Respondent's expert, Dr.

Shlomo Shinnar, argued that I.H.'s seizure disorder was primarily caused by her underlying cortical dysplasia and family history of febrile seizures, potentially exacerbated by a viral illness (RSV bronchiolitis) rather than the vaccine. He acknowledged that vaccines can cause fever and that fever can cause febrile seizures, but he opined that vaccines do not cause epilepsy and that I.H.'s epilepsy was due to her cortical dysplasia.

He noted that while prolonged febrile seizures can be associated with an increased risk of subsequent epilepsy, the link is not always causal. Special Master Katherine E.

Oler credited Petitioner's theory. She found that the medical literature supported the concept that epilepsy in individuals with cortical dysplasia can be triggered by a "second hit." She concluded that the DTaP vaccine could serve as this trigger, causing a febrile seizure that, in turn, led to epilepsy.

Special Master Oler found that the onset of I.H.'s first seizure, approximately 18 hours after vaccination, was a medically acceptable temporal relationship. She determined that Petitioner had established all three prongs of the Althen test by a preponderance of the evidence.

Entitlement was granted on February 7, 2024. The issue of damages remained unresolved in the public decision.